Timewave PK-900 User guide

OPERATING MANUAL

MODEL PK-900 DATA CONTROLLER

Timewave Technology Inc.

PROPRIETARY INFORMATION

Reproduction, dissemination or use of information contained herein for purposes other than operation and/or maintenance is prohibited without written authorization from Timewave Technology Inc.

PREFACE TO THE PK-900 OPERATING MANUAL

Please read this preface in its entirety. It contains information about how to receive warranty service from Timewave and Timewave's software update policy.

RF Interference Information To User

This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with Timewave's instructions, may cause interference to radio and TV reception. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause interference to radio or TV reception, which can be determined by turning the PK-900 on and off, the user is encouraged to try to correct the interference using one or more of the following measures:

o Re-orient the antenna of the device receiving interference. o Relocate the PK-900 or computer with respect to this device. o Plug the PK-900 into a different outlet so the PK-900 and the device are on different branch circuits.

If necessary, the user should consult the dealer or an experienced radio/TV technician for additional suggestions. The user may find "How to Identify and Resolve Radio-TV Interference Problems", a booklet prepared by the FCC, helpful.

To comply with FCC part 15 limits the following must be followed:

o YOU MUST USE SHIELDED CABLE FOR ALL CONNECTIONS

o INTERNAL MODIFICATIONS TO THE PK-900 MAY INCREASE RF INTERFERENCE AND VOID THE USERS AUTHORITY TO OPERATE THE UNIT

This PK-900 has been certified under Part 15 of the FCC rules. Operation is subject to the following two conditions:

1. This device may not cause harmful interference.

2. This device must accept any interference received, including that which may cause undesired operation.

As part of its continuing program of product improvement, Timewave reserves the right to make changes in this product's specifications or documentation. There may be inaccuracies or typographical errors in this document. Please address comments and corrections to Timewave Technology Inc., 501 W. Law

son Ave,

St. Paul, MN 55117-4771. Timewave reserves the right to incorporate and issue any

information thus supplied in whatever manner it deems suitable without incurring any obligations whatsoever.

12/02 i

Welcome

Congratulations!! You've purchased another fine Timewave product. PLEASE, before we go any further, may we ask you to FILL OUT AND RETURN the Warranty Registration Card, which has been packed with your PK-900.

Product Update Policy

From time to time Timewave may make available updates to the design of its products. We can only tell you about these updates if we have your warranty card on file. PLEASE SEND IT IN if you have not already done so.

In Case of Trouble

Application and troubleshooting assistance may be obtained by calling Timewave during our 8:00- 5:00 working hours in St. Paul, MN. Ask for the Technical Support Department. The phone number is (651) 489-5080. Please have your PK-900's serial number and version date of the software available. The version date is on the first screen that comes up when you turn on the PK-900. We will also need to know the nature of any other equipment connected to the PK-900.

You may wish to attempt to solve problems locally, using other hams or an Timewave dealer. A helpful Amateur with equipment similar to your own may literally be just around the corner. Substituting another PK-900 or Data Controller that you know is working properly for your questionable one is a diagnostic technique that will check out the rest of your station. You may also try running your PK-900 in another station if possible.

Timewave provides email Technical Support for its line of amateur radio equipment.

Email addresses are: [email protected] and [email protected]

If you call for assistance, please have your PK-900 up and running beside the phone. Our Support technician will likely ask you to perform certain keyboard routines to aid in diagnosis. If you have a voltmeter handy, you might have the PK-900 open so you can report measurements to the technician.

Many of the Timewave products that are sent to us for repair are in perfectly good order when we receive them. There is a test and alignment charge for units returned to us in working order. Please perform whatever steps are applicable from the installation sections of this manual to insure that there is a problem.

PLEASE DO NOT RETURN THE PK-900 TO US WITHOUT CONTACTING US FOR PERMISSION AND AN RMA NUMBER. WE WOULD LIKE THE OPPORTUNITY TO TROUBLESHOOT THE PROBLEM OVER THE PHONE FIRST, SAVING YOU BOTH TIME AND MONEY.

If the unit must be sent in, we will give you a Return to Manufacturer Authorization (RMA) number over the telephone. This number allows us to track your unit and provide you with its status. Please write this number on the outside of the box so we may process your unit as quickly as possible.

1/93 ii

If you send us the PK-900 by UPS it must be sent to the street address - not the post office box number. The street address is:

Timewave Technology Inc. 1025 Selby Ave., Suite 101 St. Paul, MN 55104 USA

Attn. Technical Support RMA # S????????? (obtain by telephone or email from Timewave)

We will need YOUR street address for UPS return - be sure to send it. Please include your daytime telephone number in case we need to contact you for further information.

UPS Gound (Brown Label) takes 5-6 days, Blue takes 2-3 days. Red is an overnight service and is expensive. Send the PK-900 in a way that it can be traced if we cannot verify receipt of shipment. We suggest UPS or FEDEX.

If the PK-900 is still under the original owner's warranty, Tmewave will pay the cost of the return shipment to you. The current policy is that it will be returned UPS Ground (Brown). The PK-900 may be returned as the owner states in his letter if he furnishes the return cost for the method he selects.

Typically, we will service the product in five to ten working days after it has arrived at Timewave if we have all the facts. If we must call you, it may take longer. PLEASE include a letter stating the problem and where you can be reached by telephone. If you can be reached by phone in the evening on the East Coast, let us know the number. Our current rate for non-warranty service of the PK-900 is based on time and material and return shipping. Timewave is not responsible for damage such as caused by lightning, nonprofessional alterations, poor storage/handling, etc. We will make note of any shipping damage upon receipt. See the inside back cover for Warranty information.

Should your warranty card not be on file at Timewave, you need to send the proof of purchase date to receive warranty service. Typically a copy of your bill of sale from an Timewave dealer will suffice.

The warranty is for the original owner only and is not transferable.

3/93 iii

TABLE OF CONTENTS

CHAPTER 1 - INTRODUCTION

Paragraph Page

1.1 Overview................................................... 1-1

1.1.1 Capabilities.......................................... 1-1

1.1.2 Included Components................................... 1-1

1.2 Computer or Computer Terminal Requirements................. 1-2

1.3 Station Requirements....................................... 1-2

1.3.1 System Transmitter-Receiver Performance Requirements.. 1-2

1.4 PK-900 Specifications...................................... 1-3

1.4.1 Modem Characteristics................................. 1-3

1.4.2 Processor System...................................... 1-3

1.4.3 Input/Output Connections.............................. 1-4

1.4.4 Controls and Indicators............................... 1-4

1.4.5 General............................................... 1-4

CHAPTER 2 - COMPUTER INSTALLATION

2.1 Overview................................................... 2-1

2.1.1 Equipment Required.................................... 2-1

2.2 Unpacking the PK-900....................................... 2-1

2.2.1 Connecting Power...................................... 2-2

2.3 Connecting Your Computer or Computer Terminal.............. 2-3

2.3.1 IBM-PC/XT/AT and Compatibles.......................... 2-3

2.3.2 Apple Macintosh Series of Computers................... 2-3

2.3.3 Commodore 64 and 128 Computers........................ 2-3

2.3.4 Computer Terminal..................................... 2-4

2.4 Setting Up Your Communications or Terminal Software Program 2-4

2.4.1 Terminal Programs for IBM-PCs and Compatibles......... 2-4

2.4.2 Terminal Programs for the Apple Macintosh............. 2-5

2.4.3 Terminal Programs for the Commodore 64, 64C and 128... 2-5

2.5 System Startup and Loop-back Test.......................... 2-6

2.6 Detailed RS-232 Connections for Other Computers............ 2-9

2.6.1 Apple II Series....................................... 2-9

2.6.2 Commodore C-64, C-128 and Vic 20...................... 2-9

2.6.3 IBM PCjr.............................................. 2-9

2.6.4 Tandy Color Computer.................................. 2-10

2.6.5 Tandy Model 100/102 and NEC 8201...................... 2-10

2.6.6 Other Computers with RS-232-C Ports................... 2-10

2.6.7 Other Computers with Non-Standard Serial Ports........ 2-11

2.7 Terminal (Modem) Software for Other Computers.............. 2-11

2.7.1 Terminal Programs for the Apple II, II+, IIE and IIC.. 2-12

2.7.2 Terminal Programs for the Commodore Vic 20............ 2-12

2.7.3 Terminal Program for the IBM PCjr..................... 2-12

2.7.4 Terminal Programs for the Tandy Color Computer........ 2-12

2.7.5 Terminal Programs for the Tandy 100/102 and NEC 8201.. 2-12

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CHAPTER 3 - RADIO INSTALLATION

Paragraph Page

3.1 Overview................................................... 3-1

3.1.1 Equipment Required.................................... 3-1

3.2 Receive-Only Radio Connections............................. 3-1

3.3 Transmit and Receive Radio Connections..................... 3-2

3.3.1 Transceiver's Microphone or Accessory Connector?...... 3-2

3.3.2 Connections for Specific Transceivers................. 3-2

3.3.3 Check Your Transceiver's Operating Manual............. 3-3

3.3.4 Specific Connection Points............................ 3-3

3.3.5 Begin Assembling your Radio Cable..................... 3-4

3.3.5.1 Prepare the Radio Cable.......................... 3-4

3.3.5.2 Verify the Connection Points with Your Manual.... 3-4

3.3.5.3 Prepare the Connector............................ 3-4

3.3.5.4 Wire the Connector............................... 3-4

3.3.6 Wiring Your HF Transceiver for Direct CW Keying....... 3-6

3.3.7 Connections for Direct FSK Operation on RTTY.......... 3-6

3.4 PK-900 Configuration Jumpers and Connections............... 3-7

3.4.1 Push-To-Talk (PTT) Configuration...................... 3-7

3.4.2 PK-900 Connections.................................... 3-8

3.5 Transceiver Adjustments.................................... 3-8

3.5.1 FM Transceiver Final Adjustments...................... 3-8

3.5.2 SSB Transceiver Final Adjustments..................... 3-10

3.6 Oscilloscope Connections................................... 3-12

CHAPTER 4 - PACKET RADIO

4.1 Overview................................................... 4-1

4.1.1 Getting Started....................................... 4-1

4.1.2 Making the Loopback Connection........................ 4-1

4.2 Packet Introduction........................................ 4-2

4.3 VHF/UHF Packet Operation................................... 4-4

4.3.1 What You Should See................................... 4-6

4.3.2 What It Means......................................... 4-6

4.3.3 What Happens When You Connect......................... 4-9

4.3.3.1 Standard TNCs.................................... 4-9

4.3.3.2 Mailbox Message Systems.......................... 4-9

4.3.3.3 Packet Switches.................................. 4-10

4.3.4 Who Can I Talk To?.................................... 4-12

4.3.5 Your First Real Connect............................... 4-12

4.3.6 I'm Having Trouble Connecting......................... 4-13

4.4 More Packet Features....................................... 4-14

4.4.1 LCD Status and Mode Indicators........................ 4-14

4.4.2 Automatic Greetings................................... 4-16

4.4.3 Beacon Operation...................................... 4-17

4.4.4 Digipeater Details.................................... 4-17

4.4.4.1 Are You a Digipeater?............................ 4-18

4.4.5 Monitoring Other Stations............................. 4-18

4.4.5.1 Monitoring the Packet Networking Switches........ 4-19

4.4.5.2 Monitoring Other Stations While Connected........ 4-19

4.4.5.3 Selective Monitoring............................. 4-19

4.4.5.4 The MFILTER Command.............................. 4-20

4.4.5.5 Monitor Without Callsign Headers................. 4-19

4.4.5.6 MSTAMP, The Monitor Time-Stamp Command........... 4-20

4.4.6 Packet Connects....................................... 4-20

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CHAPTER 4 - PACKET RADIO (Continued)

Paragraph Page

4.4.6.1 Time-Stamping Connects........................... 4-20

4.4.6.2 Connect Alarm.................................... 4-20

4.4.7 Packet Formatting and Editing......................... 4-21

4.4.7.1 Carriage Returns and Linefeeds in Packets........ 4-20

4.4.7.2 Canceling Lines and Packets...................... 4-21

4.4.7.3 Redisplay........................................ 4-21

4.4.7.4 The PASS Character............................... 4-21

4.4.8 Packet Transmit Timing................................ 4-22

4.4.8.1 TXDELAY and AUDELAY.............................. 4-22

4.4.8.2 AXDELAY and AXHANG............................... 4-22

4.5 Packet Protocol Basics..................................... 4-23

4.5.1 Unconnected Packets................................... 4-23

4.5.2 Connected Packets..................................... 4-23

4.5.3 FRACK and RETRY....................................... 4-23

4.5.4 PACLEN and MAXFRAME................................... 4-24

4.5.5 Reducing Errors Through Collision Avoidance........... 4-24

4.5.6 CHECK and RELINK...................................... 4-24

4.6 Multiple Connection Operation.............................. 4-25

4.6.1 Multiple Connection Description....................... 4-25

4.6.2 The Channel Switching Character....................... 4-25

4.6.3 Will You Accept Multiple Connects..................... 4-26

4.6.4 Display Multiple Connected Callsigns.................. 4-26

4.6.5 Doubling Received CHSWITCH Characters................. 4-26

4.6.6 Checking Your Connect Status with the CSTATUS Command. 4-26

4.6.7 The MULT LCD.......................................... 4-26

4.7 HF Packet Operation........................................ 4-26

4.7.1 Where to Operate HF Packet............................ 4-27

4.7.2 PK-900 HF Packet Settings............................. 4-27

4.7.3 HF Receiver Settings.................................. 4-27

4.7.4 Tuning in HF Packet Stations.......................... 4-27

4.7.5 Transmitter Adjustments............................... 4-29

4.7.6 Going On The Air...................................... 4-29

4.8 Controlling the Radio Ports................................ 4-30

4.8.1 Selecting and Loading Modems.......................... 4-30

4.8.2 Displaying Received Data.............................. 4-31

4.8.3 Controlling Your Transmitted Text..................... 4-32

4.8.3.1 Define the Channel Switching Character CHSWITCH.. 4-32

4.8.3.2 Switching Between Radio Ports.................... 4-33

4.8.3.3 More Thoughts on Port Switching.................. 4-35

4.9 Advanced Packet Operation.................................. 4-36

4.9.1 Transparent Mode...................................... 4-36

4.9.2 Gateway Operation..................................... 4-36

4.9.3 Sending 8-bit Data in Converse Mode................... 4-37

4.9.4 The Packet QRA Feature................................ 4-37

4.9.5 The CFROM Command..................................... 4-37

4.9.6 Operating in Full-Duplex.............................. 4-37

4.9.7 Identifying as a Digipeater........................... 4-37

4.9.8 Digipeater Alias Callsign............................. 4-37

4.9.9 Morse ID in Packet.................................... 4-38

4.9.10 Sharing Packet Channels With Voice Operation.......... 4-38

4.9.11 Disabling Transmit Operation.......................... 4-38

4.10 Seldom Used Commands....................................... 4-38

1/93 TOC-3

CHAPTER 4 - PACKET RADIO (Continued)

Paragraph Page

4.11 Packet Lite HF Packet Protocol Extension................... 4-38

4.11.1 Enabling Packet Lite.................................. 4-39

4.11.2 Compatibility With Standard AX.25 Stations............ 4-39

4.11.3 Packet Lite Protocol Enhancement Summary.............. 4-40

4.12 Packet Meteor Scatter Extension....................... 4-42

CHAPTER 5 - MAILDROP OPERATION

5.1 Overview of PakMail Operation.............................. 5-1

5.1.1 RAM Space for Message Storage......................... 5-1

5.1.2 System Commands....................................... 5-1

5.1.3 Your MailDrop Callsign................................ 5-1

5.1.4 Start and Stop MailDrop Operation..................... 5-1

5.2 Local Logon................................................ 5-2

5.2.1 Monitor MailDrop Operation............................ 5-2

5.2.2 Caller Prompts........................................ 5-2

5.3 SYSOP MailDrop Commands.................................... 5-3

5.4 Remote User MailDrop Commands.............................. 5-3

5.4.1 A (ABORT)............................................. 5-3

5.4.2 B (BYE)............................................... 5-4

5.4.3 E (Edit #)............................................ 5-4

5.4.4 H (HELP).............................................. 5-4

5.4.5 J (JLOG).............................................. 5-5

5.4.6 K n (KILL n [Mine])................................... 5-5

5.4.7 L (LIST [Mine])....................................... 5-5

5.4.8 R n (READ n [Mine])................................... 5-5

5.4.9 S callsign (SEND callsign)............................ 5-5

5.4.9.1 Sending Other Types of Messages with SEND........ 5-6

5.4.10 V (VERSION)........................................... 5-7

5.4.11 ? (HELP).............................................. 5-7

5.5 Sample MailDrop Session - The Remote User's Point of View.. 5-7

5.5.1 Connect and Logon..................................... 5-8

5.5.2 LIST Messages......................................... 5-8

5.5.3 READ Messages......................................... 5-8

5.5.4 KILL Messages......................................... 5-8

5.5.5 SEND Messages......................................... 5-9

5.5.6 Log Off and Disconnect................................ 5-9

5.6 Sample MailDrop Session - MailDrop SYSOP's Point of View... 5-10

5.6.1 Message Numbers....................................... 5-11

5.7 Auto-Forwarding with the PK-900 MailDrop................... 5-11

5.7.1 MailDrop Settings for Auto-Forwarding................. 5-11

5.7.2 Entering a Message for Reverse Forwarding............. 5-12

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CHAPTER 6 - BAUDOT AND ASCII RTTY OPERATION

Paragraph Page

6.1 Overview................................................... 6-1

6.2 Where to Operate Baudot and ASCII RTTY..................... 6-1

6.2.1 PK-900 Baudot RTTY Parameter Settings................. 6-1

6.2.2 HF Receiver Settings.................................. 6-2

6.2.3 Tuning in Baudot and ASCII Stations................... 6-2

6.3 Transmitter Adjustments.................................... 6-4

6.3.1 Going On The Air...................................... 6-4

6.4 A Typical Baudot RTTY Contact.............................. 6-4

6.4.1 Calling CQ............................................ 6-5

6.4.2 Answering a CQ........................................ 6-5

6.5 Baudot RTTY Operating Tips................................. 6-5

6.5.1 Changing Speed........................................ 6-6

6.5.2 Formatting Your Transmitted and Received Text......... 6-6

6.5.3 Sending a Synchronous Idle or DIDDLE.................. 6-7

6.5.4 Echoing Transmitted characters As Sent................ 6-7

6.5.5 Sending Only Complete Words........................... 6-7

6.5.6 Operating on the Wrong Sideband....................... 6-7

6.5.7 Framing Errors........................................ 6-7

6.5.8 UnShift-On-Space (USOS)............................... 6-7

6.5.9 Operating at Commercial or VHF Wide RTTY Shifts....... 6-8

6.5.10 The CODE Command for International RTTY Compatibility. 6-8

6.5.11 Copying Encoded RTTY Transmissions.................... 6-8

6.6 ASCII RTTY Operation....................................... 6-8

6.6.1 Starting ASCII Operation.............................. 6-8

6.6.2 ASCII RTTY Operating Tips............................. 6-9

6.6.3 Changing ASCII Baud Rates............................. 6-9

6.6.4 Operating at Commercial or Wide ASCII RTTY Shifts..... 6-10

6.6.5 Other RTTY Commands for ASCII Operation............... 6-10

6.7 Simultaneous RTTY and Packet Operation..................... 6-10

6.7.1 Selecting Modems...................................... 6-11

6.7.2 Displaying Received Data.............................. 6-12

6.7.3 Switching Between Ports............................... 6-12

6.7.4 More Thoughts on Port Switching....................... 6-14

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CHAPTER 7 - AMTOR AND NAVTEX OPERATION Paragraph Page

7.1 Overview................................................... 7-1

7.2 Where to Operate AMTOR..................................... 7-1

7.2.1 PK-900 AMTOR Parameter Settings....................... 7-1

7.2.2 Entering Your SELective CALling Code (MYSELCAL)....... 7-1

7.2.3 Entering Your SELective CALling Code (MYIDENT)........ 7-2

7.2.4 Enter the AMTOR Mode.................................. 7-2

7.2.5 HF Receiver Settings.................................. 7-2

7.2.6 Tuning in AMTOR Stations.............................. 7-3

7.3 Transmitter Adjustments.................................... 7-5

7.3.1 Going On The Air...................................... 7-5

7.3.2 Calling CQ in FEC AMTOR............................... 7-5

7.3.3 Answering an FEC AMTOR CQ............................. 7-6

7.3.4 ARQ AMTOR Operating Fundamentals...................... 7-6

7.3.5 Ending an ARQ AMTOR Contact........................... 7-6

7.3.6 LCD Status and Mode Indicators........................ 7-7

7.4 AMTOR Operating Tips....................................... 7-8

7.4.1 ARQ Break-In (ACHG Command)........................... 7-8

7.4.2 Entering Your Auto-AnswerBack (AAB)................... 7-8

7.4.3 Operating AMTOR with Other Modems and Shifts.......... 7-9

7.4.4 Speed Change Not Permitted............................ 7-9

7.4.5 Echoing Transmitted Characters as Sent (EAS).......... 7-9

7.4.6 Sending Only Complete Words (WORDOUT)................. 7-9

7.4.7 Operating on the Wrong Sideband....................... 7-10

7.5 Monitoring ARQ AMTOR Contacts with ALIST................... 7-10

7.6 AMTOR MailDrop Operation................................... 7-10

7.6.1 Special Operation Considerations...................... 7-10

7.6.2 Settings For AMTOR MailDrop Operation................. 7-11

7.6.3 Starting AMTOR MailDrop Operation..................... 7-11

7.6.4 Local Logon to the MailDrop........................... 7-11

7.6.4.1 Remote Logon to your AMTOR MailDrop.............. 7-11

7.6.5 Caller Prompts........................................ 7-12

7.6.6 Monitor MailDrop Operation............................ 7-13

7.6.7 SYSOP MailDrop Commands............................... 7-13

7.6.8 Remote User MailDrop Commands......................... 7-13

7.6.8.1 A (ABORT) (Remote only).......................... 7-13

7.6.8.2 B (BYE).......................................... 7-13

7.6.8.3 H (HELP)......................................... 7-13

7.6.8.4 J (JLOG) (Remote Only)........................... 7-13

7.6.8.5 K n (KILL n [Mine]).............................. 7-13

7.6.8.6 L n (LIST [Mine])................................ 7-14

7.6.8.7 R n (READ n [Mine]).............................. 7-14

7.6.8.8 S callsign (SEND callsign)....................... 7-14

7.7 Simultaneous AMTOR and Packet Operation.................... 7-14

7.7.1 Selecting Modems..................................... 7-15

7.7.2 Displaying Received Data.............................. 7-16

7.7.3 Switching Between Ports............................... 7-16

7.7.4 More Thoughts on Port Switching....................... 7-18

7.7.5 Dual Port AMTOR/Packet MailDrop Operation............. 7-18

7.7.5.1 Packet MailDrop Command Settings................. 7-19

7.7.5.2 AMTOR MailDrop Command Settings.................. 7-19

7.7.5.3 Dual Port MailDrop Operation Notes............... 7-19

7.8 AMTOR Switching-Time Considerations........................ 7-19

7.8.1 Suggested AMTOR Operating Settings.................... 7-20

7.8.2 Possible Areas for AMTOR Performance Improvement...... 7-20

7.9 NAVTEX Operation........................................... 7-21

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CHAPTER 8 - MORSE OPERATION

Paragraph Page

8.1 Overview................................................... 8-1

8.2 Where to Operate Morse..................................... 8-1

8.2.1 Entering the Morse Mode............................... 8-1

8.2.2 HF Receiver Settings.................................. 8-1

8.2.3 Tuning in Morse Stations.............................. 8-1

8.3 Going On The Air........................................... 8-2

8.3.1 A Typical Morse Contact............................... 8-3

8.4 Morse Operating Tips....................................... 8-3

8.4.1 The PK-900 Morse Modem................................ 8-4

8.4.2 Speed Change (MSPEED)................................. 8-4

8.4.3 Echoing Transmitted Characters As Sent (EAS).......... 8-4

8.4.4 Sending Only Complete Words (WORDOUT)................. 8-4

8.4.5 Speed Lock (LOCK)..................................... 8-4

8.5 Special Morse Characters................................... 8-5

8.6 Morse Code Practice........................................ 8-5

CHAPTER 9 - FACSIMILE (FAX) OPERATION

9.1 Overview................................................... 9-1

9.1.1 Facsimile............................................. 9-1

9.1.2 Slow Scan Television.................................. 9-2

9.2 Finding FAX Frequencies.................................... 9-2

9.2.1 Finding SSTV Frequencies.............................. 9-3

9.3 FAX and SSTV Analog Signal Operation....................... 9-3

9.4 Black & White FAX Operation................................ 9-4

9.4.1 HF Receiver Settings.................................. 9-4

9.4.2 Tuning In HF Facsimile Stations....................... 9-4

9.4.3 PK-900 Facsimile Parameter Settings................... 9-5

9.5 Receiving Facsimile Broadcasts............................. 9-5

9.6 Facsimile Operating Tips................................... 9-6

9.6.1 Setting PRTYPE ....................................... 9-6

9.6.2 Printing Direction (LEFTRITE)......................... 9-6

9.6.3 Inverting Black and White (FAXNEG).................... 9-7

9.6.4 Display Density (GRAPHICS)............................ 9-7

9.7 Displaying Other Services.................................. 9-7

9.7.1 The PK-900 FAX Modem.................................. 9-7

9.8 Transmitting FAX........................................... 9-7

9.9 Adjusting the PK-900 4.0 MHz Master Oscillator............. 9-8

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CHAPTER 10 - SIGNAL IDENTIFICATION AND TDM OPERATION

Paragraph Page

10.1 Overview................................................... 10-1

10.2 SIAM Operation............................................. 10-1

10.2.1 Tuning In FSK Narrow and Wide Stations................ 10-2

10.3 Using the SIAM Mode........................................ 10-4

10.3.1 Copying Encoded RTTY Transmissions.................... 10-4

10.3.2 The CODE Command for International RTTY Compatibility. 10-5

10.4 TDM Receive Operation...................................... 10-5

10.4.1 TDM Parameters........................................ 10-5

10.4.2 Monitoring TDM Signals................................ 10-5

10.4.3 Where to Find TDM Signals............................. 10-6

CHAPTER 11 - PACTOR OPERATION

11.1 Overview................................................... 11-1

11.2 Where to Operate PACTOR.................................... 11-1

11.3 PK-900 Parameter Settings.................................. 11-2

11.3.1 Entering Your Callsign (MYPTCALL)..................... 11-2

11.3.2 Entering the PACTOR Mode.............................. 11-2

11.4 HF Receiver Settings....................................... 11-3

11.5 Tuning in PACTOR Stations.................................. 11-3

11.6 Operating on PACTOR........................................ 11-4

11.6.1 Going On the Air...................................... 11-5

11.6.2 Calling CQ in Unproto Mode............................ 11-5

11.6.3 Answering an Unproto PACTOR CQ........................ 11-6

11.6.3.1 Ending an ARQ PACTOR Contact..................... 11-7

11.6.4 Long Path Contacts.................................... 11-7

11.6.5 LCD Status and Mode Indicator......................... 11-8

11.7 PACTOR Operating Tips...................................... 11-9

11.7.1 ARQ Break-In (ACHG Command)........................... 11-9

11.7.2 Entering Your Auto-Answer Back (AAB).................. 11-9

11.7.3 Operating PACTOR on Other Modem Frequencies and Shifts 11-10

11.7.4 Automatic Speed Change................................ 11-10

11.7.5 Echoing Transmitted Characters As Sent (EAS).......... 11-10

11.7.6 Sending Only Complete Words (WORDOUT)................. 11-11

11.7.7 Operating on the Wrong Sideband....................... 11-11

11.7.8 Little Used PACTOR Commands........................... 11-11

11.8 Monitoring ARQ PACTOR Contacts with PTL.................... 11-12

11.9 PACTOR MailDrop Operation.................................. 11-12

11.9.1 Special Operating Considerations...................... 11-12

11.9.2 Settings For PACTOR MailDrop Operation................ 11-13

11.9.3 Starting PACTOR MailDrop Operation.................... 11-13

11.9.4 Local Logon to the MailDrop........................... 11-13

11.9.4.1 Remote Logon to your PACTOR MailDrop............. 11-13

11.9.5 Caller Prompts........................................ 11-13

11.9.6 Monitor MailDrop Operation............................ 11-14

11.9.7 SYSOP MailDrop Operation.............................. 11-14

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Paragraph Page

11.9.8 Remote User MailDrop Commands......................... 11-14

11.9.8.1 A (ABORT) (Remote Only).......................... 11-14

11.9.8.2 B (BYE).......................................... 11-14

11.9.8.3 H (HELP)......................................... 11-14

11.9.8.4 J (JLOG)......................................... 11-14

11.9.8.5 K n (KILL n [MINE]............................... 11-14

11.9.8.6 L (LIST [MINE]).................................. 11-15

11.9.8.7 R n (READ n [MINE]).............................. 11-15

11.9.8.8 S callsign (SEND callsign)....................... 11-15

11.9.8.9 V (VERSION)...................................... 11-15

11.9.8.10 ? (HELP)......................................... 11-15

11.10 Simultaneous PACTOR and Packet Operation.............. 11-15

11.10.1 Selecting Modems................................. 11-16

11.10.2 Displaying Received Data......................... 11-16

11.10.3 Switching Between Ports.......................... 11-17

11.10.4 More Thoughts on Port switching.................. 11-19

11.10.5 Dual Port PACTOR/Packet Maildrop Operation....... 11-19

11.10.5.1 Packet MailDrop Command Settings............ 11-20

11.10.5.2 PACTOR MailDrop Command Settings............ 11-20

11.10.5.3 DualPort MailDrop Operation Notes........... 11-20

11.11 PACTOR Switching Time Considerations.................. 11-21

11.11.1 Suggested PACTOR Operating Settings.............. 11-21

11.11.2 Possible Areas For PACTOR Performance Improvement 11-21

APPENDICES

APPENDIX A PK-900 COMMAND SUMMARY

APPENDIX B PK-900 SCHEMATIC DIAGRAM

APPENDIX C PK-900 PARTS PICTORIAL

APPENDIX D SELF TEST ROUTINE

APPENDIX E SPECIFIC RADIO CONNECTIONS

APPENDIX F WARRANTY

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The rest of this page is blank.

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CHAPTER 1

INTRODUCTION

1.1 Overview

The PK-900 was designed by AEA to provide you the Amateur the complete digital operating position when coupled with a Personal Computer or Computer Terminal. The PK-900 couples your HF or VHF/UHF (or both) voice transceivers to your computer or terminal so you can use its keyboard and display to "talk" to other Amateurs.

1.1.1 Capabilities

The PK-900 allows you to transmit and receive all legal Amateur digital modes that are popular on both HF and VHF. In addition you can send and receive black-and-white Weather FAX. The PK-900 can receive other modes such as TDM, NAVTEX and bit-inverted Baudot RTTY. These capabilities together with SIAM (Signal Identification and Acquisition Mode) make the PK-900 ideal for the digital Short Wave Listener as well.

The PK-900 with your Computer or Terminal allows you to transmit and receive the following modes:

o AX.25 Packet, both HF and VHF (Chapter 4) o Baudot and ASCII RTTY (Chapter 6) o AMTOR/SITOR CCIR Rec. 476 and 625 (Chapter 7) o Morse Code (Chapter 8) o HF Weather FAX (Chapter 9) o PACTOR (Chapter 11)

In addition the PK-900 receives the following modes: o NAVTEX marine broadcasts (Chapter 7) o TDM (Time Division Multiplex) signals (Chapter 10) o Bit-inverted Baudot RTTY (Chapter 10)

The PK-900 also has the following special features:

o SIAM for SWLing (Chapter 10) o PakMail Maildrop for Automatic Packet Message Handling (Chapter 5) o AMTOR MailDrop Operation (Chapter 7) o KISS mode for TCP/IP and special Packet applications (Appendix A) o HOST mode for Host application programs (Technical Manual) o Dualport operation with gateway (Chapter 4)

1.1.2 Included Components

Your PK-900 Data Controller package contains the following items:

o One PK-900 Data Controller o PK-900 Operating Manual (this manual) o Cables to connect your PK-900 to two separate radios o Connector package to help set up your PK-900 o Radio Port "Loop-back" connector with jumper o RS-232 Serial Cable with a DB-25 connector

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1.1.3 OPTIONS

o 9600 Baud internal G3RUH/K9NG compatable modem. o AEA-FAX 900 HF Gray-scale fax reception program

1.2 Computer or Computer Terminal Requirements

You will need a Computer or Computer Terminal to "talk to" or control your PK-900. If you are using a Computer, you will need a Communications Program or Terminal Program as it is sometimes called. The most popular computers are the IBM-PC and its compatibles, the Apple Macintosh and the Commodore-64/128. These, and most other computers can be made to work with the PK-900.

Although not required, AEA has program packages for the IBM-PC and the Macintosh computers that are customized for radio communications. These packages are PC-PAKRATT II with FAX for the IBM-PC and compatibles, and MACRATT with FAX for the Apple Macintosh. Details of how to connect each of these computers to the PK-900 can be found in Chapter 2 of this manual. You may use other computers than those mentioned above if the following technical requirements are met.

The Computer or Computer Terminal you plan to use must have an RS-232 Serial Communications port. You will also need a Communications Program that allows your computer to communicate over the RS-232 port using the ASCII character set. Details for connecting many computers can be found in Chapter 2 of this manual.

1.3 Station Requirements

We presume that you already have an operating radio transceiver or Short-Wave receiver to which you will connect your PK-900. In the Amateur bands most of the VHF activity occurs on the 2-meter FM band, while most of the HF activity occurs on the 20-meter band. An HF receiver or transceiver must be capable of SSB operation. While no specific brand of transceiver is required, we recommend that a modern transceiver (built in the last 20 years) capable of operation on one of the two frequency bands mentioned above be used. Specific transceiver connections are described in Chapter 3 of this manual.

1.3.1 System Transmitter-Receiver Performance Requirements

Most modern radio transceivers are capable of excellent performance in Morse, Baudot and ASCII RTTY, AMTOR and packet radio. Although AMTOR Mode A (ARQ) operation imposes more demanding switching speed requirements than the other operating modes, most radios will operate in both AMTOR modes without any modifications. Radio switching times are less critical in packet radio operation. See the AMTOR operating section for further details on timing requirements.

Your PK-900 provides software-controlled timing variations that permits operation with nearly all the HF and VHF/UHF radios in general use today.

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1.4 PK-900 Specifications

As part of its program of product improvement, AEA reserves the right to make changes in this product's specifications. Changes may also be made to the information in this document and incorporated in revisions to this manual. Prices and specifications are subject to change without notice or obligation.

1.4.1 Modem Characteristics

Port 1: Demodulator: Programmable Limiter-discriminator type, preceded by an 8-pole Chebychev 0.5-dB ripple bandpass filter. Receive Band-pass: Automatically switched by operating mode VHF packet: Center frequency 1700 Hz,

HF (except CW) Center frequencies: 1700, 2210,

2337.5 or 2550 Hz depending on frequency shift chosen. Bandwidth: 200, 470, 725, or 1150, optimized for operating mode.

CW Center frequency 750 Hz, bandwidth 200 Hz

Modulator Crystal controlled, 1 Hz step programmable, phase-continuous, Direct Digital Synthesis sine wave generator

Output Level: 5 to 100 millivolts RMS into 600 Ohms, adjustable by a rear-panel control

Port 2: Modulator/Demodulator AMD 7910 'World Chip' FSK Modem

Modem Tones: Bell 103 and 202

Output Level: 5 to 100 millivolts RMS into 600 Ohms, adjustable by a rear-panel control

Options: 9600 baud direct FSK packet modem (G3RUH/K9NG compatible)

Grey scale HF FAX receiving program

1.4.2 Processor System

Protocol conversion: Zilog Z-180 (64180) microprocessor RAM: 64 Kilobytes ROM: Up to 256 Kilobytes of ROM may be used

Display and memory ARQ processor: 68HC05B4 DSS processor: 68HC05C4

Hardware HDLC: Zilog 8530 SCC

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1.4.3 Input/Output Connections

Radio Interface: Two five-pin DIN connectors; Input/Output Lines Receive audio Transmit audio +/- Push-To-Talk (PTT) (+25 / - 40 VDC) External squelch input Ground

Direct FSK Outputs: Normal and reverse for each radio port

CW keying Outputs: Positive: +100 VDC max, at up to 100 mA Negative: -30 VDC max, at up to 20 mA

Terminal Interface: RS-232-C 25-pin DB-25S connector Input/Output RS-232-C with full handshake (hardware and software)

Terminal Data Rates Autobaud selection of 110, 150, 300, 600, 1200, 2400, 4800, 9600 and 19200 BPS.

1.4.4 Controls and Indicators

Front Panel Indicators: Twenty-segment, selectable display type: discriminator, magic eye or zero center bargraph indicator for tuning radio port 1.

Power Switch Front panel push-on push-off

Threshold Control Front panel knob controlling DCD sensitivity of radio port 1 demodulator

Status Display LCD Status Display, with variable intensity backlight, showing Mode and data controller status for both radio ports

1.4.5 General

Power Requirements: +13 VDC (12 to 16 VDC) at 1100 mA (max) 880 mA with LCD back light off

Mechanical: Overall, W 11 13/16" x D 12" x H 3.1/2" (300 mm X 305 mm X 89 mm) Weight 6 pounds 4 oz. (2.84 kilograms)

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CHAPTER 2

COMPUTER INSTALLATION

2.1 Overview

In this chapter we will connect the PK-900 to the RS-232 Serial port of your Computer or Computer Terminal. After the Serial connection has been made we will perform a quick check of the internal software. Finally we will check the PK-900's modem by performing a Packet "loop-back" test. When you have completed this chapter, you will be ready to connect the PK-900 to your receiver or transceiver and begin using it on the air.

2.1.1 Equipment Required

You will need the following for this chapter:

o your PK-900 Data controller;

o a 13.6-volt DC, 1.5-amp (or greater) regulated power supply such as those sold by Radio Shack (or a Timewave AC-5 or AC-4); (the power supply must be able to supply at least 13 VDC to the PK-900 while it is operating under load)

o the included PK-900 DC power cord unless the AC-4 is used;

o your Computer or Computer Terminal;

o a Communications or Terminal Emulation program for your computer; (not needed if a Computer Terminal is being used)

o the included RS-232 cable with a 25-pin "D" connector on each end;

o one of the included 5-pin shielded "radio cables"; (note that the radio cables may arrive as a single 10-ft. cable which should be cut in half producing two 5-ft. cables.)

o The two, wire "Loop-back" jumpers necessary for testing;

o wire cutters and strippers or a small pocket knife, a small straight-blade screwdriver and a medium Phillips-head screwdriver.

2.2 Unpacking the PK-900

Carefully remove the PK-900 from the box and its plastic bag. Inspect the unit for signs of damage that may have occurred in shipping. If there is visible damage, please contact the dealer or shipper. Do not attempt to install or use a damaged PK-900.

We will be discussing some of the Controls, Indicators and Connections in this installation so take a few moments to familiarize yourself with them. The figures on the next pages may help with their locations.

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2.2.1 Connecting Power

MAKE SURE YOUR POWER SUPPLY IS OFF AND UNPLUGGED BEFORE WIRING

1. If you are using the AEA AC-4 or Timewave AC-5, skip to 5. Otherwise, locate the PK-900 Power Cable in the accessory bag . Strip off just enough insulation from the ends to connect it to your 13-14 Volt DC regulated power supply.

2. The Center pin of the coaxial power plug is POSITIVE. Connect the lead with the White stripe to the POSITIVE (+) lead on your power supply. Check this with an Ohm-meter if you have one.

3. Connect the solid Black (GROUND) lead to the NEGATIVE (-) lead of your power supply.

4. Connect the power plug to the 13 VDC Power Receptacle on the left rear of the PK-900. DO NOT CONNECT YOUR COMPUTER YET.

5. Plug in your power supply or AC-4 and turn on power. Turn on the PK-900 by depressing the Power Switch on the front of the unit. At power-on, the LCD Status display on the left should light. At this point, turn OFF the PK-900 and move on to section 2.3.

If the Status display does not light, then re-check the above steps to insure that 12-14 VDC is available at the power plug and the center pin is POSITIVE.

If the Status display lights, and status indicators other than the DCD indicators are displayed, then the PK-900 has already been initialized. If the PK-900 has been initialized it is ready to communicate with a computer or terminal at a specific baud rate (probably 300, 1200, 2400, 4800 or 9600 baud). If you know what this baud rate is then you should continue with the installation at section 2.3 keeping this in mind.

If you do not know the baud rate the PK-900 has been initialized to then you should reset the PK-900 by holding the rear-panel RESET switch at the same time you turn on the power switch. After this is done, no status indicators on the LCD Status display should be on with the possible exception of either or both of the two DCD indicators.

If the above did not produce the blank status indication, (ignoring the DCD indicators) contact the Timewave Technical Support Department as described in the front of this manual.

Figure 2-1 PK-900 Front Panel Controls and indicators

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Figure 2-2 PK-900 Rear Panel Connections and Controls

2.3 Connecting Your Computer or Computer Terminal

MAKE SURE THE PK-900 AND YOUR COMPUTER ARE SWITCHED OFF o Locate the PK-900 Serial Cable. Connect the 25-pin Female connector to the RS-232 connector on the PK-900 rear panel.

o Connect the other end of this cable (Female DB-25) to the RS-232 Serial Port of your personal computer or Computer Terminal. Details on connecting to common machines are listed below.

NOTE: This cable was designed to connect directly to a 25-pin IBM-PC compatible RS-232 port. Many machines on the market today support this configuration. Some less-common machines are listed in section

2.6. Please be certain you have properly connected the PK-900 to your RS-232 computer or Terminal then proceed to section 2.4.

2.3.1 IBM-PC/XT/AT and Compatibles

IBM compatible 25-pin RS-232 serial ports should connect directly to the supplied serial cable. Some IBM compatible machines are equipped with a 9-pin serial port. For these machines a DB-9 to DB-25 adapter should be obtained from a Radio Shack store or a computer dealer.

2.3.2 Apple Macintosh Series of Computers

AEA presently sells the program MacRATT with FAX which contains the serial cable for the newer models of the Macintosh (models Mac + and later). If you intend to use another communications program with the PK-900 a Modem adapter cable must be purchased from your Apple dealer to connect the Mac to your PK-900. For the newer machines such as the Mac +, Mac SE and Mac II, a mini-8 to DB-25 adapter cable is required (included with the AEA MACRATT with FAX program). For the older Mac 128 and 512 machines, a DB-9 to DB-25 adapter cable from your Apple dealer is needed.

2.3.3 Commodore 64 and 128 Computers

The Commodore 64/128 computers do not have an RS-232 port as standard equipment. For these machines RS-232 adapters are available from manufacturers such as Commodore or OMNITRONIX. These may work with modem or terminal programs for your Commodore. Section 2.4 of this chapter deals more with programs for personal computers. The AEA Program COM-PAKRATT With FAX is NOT recommended for the PK-900.

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2.3.4 Computer Terminal

If you have an RS-232 Computer Terminal, sometimes called a Dumb Terminal, Smart-Terminal or ASCII-Terminal, you may need to change the gender of the cable provided with your PK-900. This can be accomplished with an inexpensive double-male RS-232 gender changing adapter available from Radio Shack and other computer dealers. The Radio Shack part number is 26-243.

2.4 Setting Up Your Communications or Terminal Software Program

If you will be using your PK-900 with a Computer, you will need to read parts of this section to set up your Communications or Terminal Software. If you will be using your PK-900 with a Terminal you will not need any software and may skip to section 2.5.

Setting up a communications program for your PK-900 is very important. How your screen looks when you use your PK-900 depends completely on your Communications program. AEA currently makes available programs for the IBM-PC and compatibles and the Apple Macintosh computers. These products are customized for radio communications and are available at extra cost from your AEA dealer.

The PK-900 operates in much the same manner as a telephone modem and most modem Terminal Programs will control a PK-900 quite nicely. Some of these programs are "Public Domain" which means they are FREE. Other Terminal Programs are "Share-ware" which means you may get them from a friend and try them before you buy them. Whether you are using an AEA program or one of your own choosing, see the section below for the particular type of computer you plan to use.

2.4.1 Terminal Programs for IBM PCs and Compatibles

Although you can use almost any terminal program with your IBM PC or close compatible, AEA currently sells the PC-PAKRATT II w/FAX program which provides many features not available in "telephone modem" programs. See your AEA dealer for information on PC-PAKRATT II w/FAX.

If you already have the PC-PAKRATT II program, follow the program manual and install the software on your computer. You should also read through the PACKET OPERATION chapter of the PC-PAKRATT II manual. Familiarity with Packet operation of PC-PAKRATT will be necessary for performing a quick-check of the PK-900 in section 2.5 of THIS manual.

As we mentioned above, an AEA program is not required to use the PK-900. Many terminal programs can be found throughout the amateur radio community or can be downloaded from Compuserve, GEnie and from many telephone bulletin boards.

A partial list of PC programs tested with the PK-900 includes:

PROCOMM, CROSSTALK-XVI, SMARTCOMM, RELAY, BITCOM, QMODEM, PC-TALK, CTERM, HAMCOM, HAMPAC, YAPP and the terminal program included with Microsoft Windows 3.0 (tm).

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Follow the installation directions that come with the Terminal program you wish to use. Once installed on the computer, you should start the program and set the communication parameters for the following:

Data Rate = 1200 bits per second (Bauds) Data bits = 7 Parity = EVEN Stop bits = 1

Once these settings have been achieved and the correct serial communications port chosen, you may proceed to section 2.5.

2.4.2 Terminal Programs for the Apple Macintosh

Although you can use almost any terminal program with your Macintosh, AEA presently sells the MACRATT with FAX program which provides many features not available in "telephone modem" programs. See your AEA dealer for information on MACRATT with FAX.

If you already have the MACRATT program, please follow the program manual and install the software on your Mac. You should also read through the PACKET OPERATION chapter of the MACRATT manual. Familiarity with Packet operation of MACRATT will be necessary for performing a quick check of the PK-900 in section 2.5 of THIS manual.

As we mentioned above, an AEA program is not required to use the PK-900. Many terminal programs can be found throughout the amateur radio community and can be downloaded from Compuserve, GEnie and from many telephone bulletin boards.

A partial list of Mac programs tested with the PK-900 includes:

MAC TERMINAL, RED RYDER, MICROPHONE, SMARTCOMM II and MOCK TERMINAL

Follow the installation directions that come with the Terminal program you wish to use. Once installed on the computer, you should start the program and set the communication parameters for the following:

COMPATIBILITY: 1200 bauds, 7 bits/character, even parity, Handshake XON/XOFF, FULL-DUPLEX, Modem connection, "telephone" port.

Once these settings have been achieved, proceed to section 2.5.

2.4.3 Terminal Programs for the Commodore 64, 64C and 128

Although AEA presently sells the COM-PAKRATT with FAX program package for the PK-232, this program cannot access all the features of the PK-900. AEA therefore cannot recommend using the COM-PAKRATT package with the PK-900. If you already have this package, it will certainly get you started with the PK-900 by using the "Dumb Terminal" mode. You may wish to find another program which provides more features than are available in the COM-PAKRATT program in the Dumb Terminal Mode. Other ideas for terminal programs for the Commodore-64 series of computers are listed below.

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Many terminal programs can be found throughout the amateur community or can be downloaded from Compuserve and from many telephone bulletin boards. In addition a BASIC communications program is listed in the Programmer's Reference Guide published by Commodore. Use the program listing for "True ASCII". We suggest you operate your PK-900 at 300 bauds with these computers to avoid possible speed difficulties.

Follow the installation directions that come with the Terminal program you wish to use. Once installed on the computer, you should start the program and set the communication parameters for the following:

Data Rate = 300 bits per second (Bauds) Data bits = 7 Parity = EVEN Stop bits = 1

Once these settings have been achieved, proceed to section 2.5.

2.5 System Startup and Loop-back Test

Make sure that you have connected your PK-900 to a 12-14 Volt DC power source and to the RS-232 port of your computer or Terminal. If you are using a computer, you must also have a communications program and be familiar with its operation. You are now ready to begin the following PK-900 Startup and Loop-back test procedure.

1. Don't connect any cables to your radio yet!

2. Remove the 16 gauge wire "Loop-back" connectors from the PK-900 accessory bag.

3. Plug these into pins 1 and 4 of each of the radio connectors on the PK-900's rear panel.

4. Set both AFSK levels on the back panel of the PK-900 to 50% rotation (straight up and down) using a small screwdriver.

5. Turn on your computer. Load and run your communications program.

If you are using an AEA PAKRATT program, follow the program instructions to enter the Packet mode, then skip to step 11.

If you are using another Terminal Program or a Computer Terminal, Set your computer's terminal program to:

o 1200 bauds (if available); o seven-bit word; o even parity; o one stop bit.

NOTE: You may use other terminal baud rates with the PK-900 - we recommend 1200 baud here to keep this procedure easy and consistent.

6. Press the PK-900's power switch to the ON position. At power-on, the LCD Status display on the left should light,

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showing either no status indications or one or both of the DCD indicators. If the Status display lights and other status indicators are displayed, then the PK-900 has already been initialized. If you know the terminal baud rate the PK-900 has been set to, you may proceed to step 11; otherwise you must reset the PK-900 as described below.

To reset the PK-900, simply hold the rear-panel RESET switch in at the same time you turn on the power switch. After this is done, then the only LCD Status indicators showing may be the DCD indicators. If your serial port is operating at 1200 bauds as we recommend, you'll see the "autobaud" message:

Please type a star ( * ) for autobaud routine.

If your serial port is operating at 300, 2400, 4800 or 9600 bauds, you may see some "garbage" characters. This is normal and you should proceed with step 7.

7. Type an asterisk (*). When the PK-900 has "recognized" your computer's data rate, the CMD LCD will light. Your screen will then display the sign-on message:

PK-900 is using default values.

Make note of the Release date on the first page of this manual. This is important should you ever call AEA for technical support. It should match the firmware release sticker on the bottom of your PK-900.

8. If you are using an AEA program, follow the instructions in the program manual to enter the packet callsign (MYCALL) of AAA into the PK-900. Even though this is not your callsign, please do this for this procedure. You must change it to YOUR OWN CALLSIGN after completing this procedure.

If you are using a Computer Terminal or a non-AEA terminal program the following will set your packet callsign to AAA:

Enter MYCALL by typing MY AAA <Enter> (or <RETURN>). (<RETURN> or <Enter> means type the single key on your keyboard.) Your monitor should display:

MYcall was PK900/PK900 MYcall now AAA/PK900

9. If you are using an AEA program follow the instructions to CONNECT in packet mode to AAA. Since you have just entered your callsign as AAA, you will connect to yourself.

If you are using a Computer Terminal or a non-AEA program,

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entering the following after the "cmd:" command mode prompt will cause the PK-900 to Connect to AAA:

C AAA <Enter>

After a few moments, your monitor should display:

*** CONNECTED to AAA

10. Type HELLO SELF <Enter> After a few moments, your monitor should echo the same message.

If you have gotten this far then the digital section of the PK-900 and the VHF packet modem of port 1 are both working.

11. We will now check the PK-900's HF modem. If you are using an AEA program, follow the instructions to select the HF modem by turning the VHF Parameter OFF; this will automatically set the radio baud rate HBAUD to 300 for HF packet work.

If you are using a Computer Terminal or a non-AEA terminal program, the following sets the HF mode of the PK-900:

Type <CONTROL-C>. (Type C while pressing the <Ctrl> key down.) Your monitor should respond with the command prompt:

cmd:

Then enter VHF OFF <Enter> Your monitor should respond with:

Vhf was ON/ON Vhf now OFF/ON

Then enter HB 300 <Enter> Your monitor should respond with:

HB was 1200/1200 HB now 300/1200

12. If you are using an AEA program type HELLO SELF <Enter> Your monitor should soon echo the message you've just typed.

If you are using a Computer Terminal or a non-AEA terminal program, you must first type CONV or K followed by a <Enter>. Now you may type a few characters. Your monitor should soon echo the characters you've just typed.

13. If you are using an AEA program, follow the instructions to DISCONNECT from a Packet station.

If you are using a Computer Terminal or a non-AEA terminal program the following will cause the PK-900 to DISCONNECT:

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Enter <CONTROL-C> Your monitor should respond with the command prompt:

cmd:

Enter D <Enter> Your monitor should respond with:

cmd:*** DISCONNECTED: AAA p1 AAA*>AAA (UA)

If all of the above steps were successful, you've completed the quick check and are ready to proceed to Chapter 3. In Chapter 3 you will connect your PK-900 to your radio and begin using it "on the air".

If you have problems with the steps shown above, go back to Step 1 AFTER checking all cables and connectors. Read each step again carefully. The most common problems are trying to connect to a call different from AAA, not having the "loopback" jumpers in the correct pins, or not setting the AFSK levels to 50% rotation.

If you still have problems, leave your PK-900 ON and contact AEA's Technical Support Department as suggested in the front of this manual.

2.6 Detailed RS-232 Connections for Other Computers

If the type of computer you plan to use with the PK-900 was not mentioned in the beginning of this chapter, you may find specific connection information in the sections below. You will also need a Communications program to use with your computer which AEA can not provide. See section 2.7 for information regarding Communication programs for many of these machines.

Some computers require a serial port adapter card that incorporates the necessary RS-232-C interface circuitry. The IBM-PC and Apple II series of computers are good examples of this.

Computers that do not have a serial port or do not permit use of a suitable adapter or level converter cannot be used with the PK-900.

2.6.1 Apple II Series

The Apple II, II+ and IIe computers require an RS-232 Serial card to connect to your PK-900. The most popular we know about is the Super-Serial Card which should be available from your Apple dealer.

2.6.2 Commodore C-64, C-128 and Vic 20

Commodore, OMNITRONIX and other manufacturers sell a signal level converter that is installed in the User Port Connector on the rear of the computer. The converter changes the computer's internal TTL voltage levels to the proper RS-232-C voltage levels and polarities.

2.6.3 IBM PCjr

The PCjr uses standard RS-232-C voltage levels; however, the

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connector is not standard and is hard to find. Pin-out information can be found in the IBM PCjr Technical Reference Manual. Some dealers sell a 'IBM PCjr Adapter Cable for Serial Devices' that converts the connector on the PCjr to standard RS-232-C. The cable attaches between the PCjr and the PK-900 Serial Cable.

2.6.4 Tandy Color Computer

The CoCo series (except for the Micro CoCo) uses a four-pin DIN connector for its serial interface. Wire a cable as shown below. All necessary parts should be available from your Radio Shack dealer.

CoCo PK-900 (DB25P)

4 ..................... 2

2 ..................... 3

3 ..................... 7

2.6.5 Tandy Model 100/102 and NEC 8201

The Model 100/102 and NEC 8201 have built-in standard RS-232 serial ports which are compatible with the PK-900. You'll need a DB-25 male-male gender changing adapter to use the supplied PK-900 Serial Cable.

2.6.6 Other Computers with RS-232-C Ports

If your computer has an RS-232 port, consult your computer manuals to see which pins are used for Transmit-Data, Received-Data and Signal Ground. Read the manufacturer's recommendations for connecting the serial port to a modem and connect your PK-900 in the same way.

Your PK-900 is configured as Data Communications Equipment (DCE) which receives data on pin 2 of the 25-pin DB-25 connector or pin 2 of the 25 pin cable supplied with the unit. Most computers and terminals are configured as Data Terminal Equipment (DTE) transmitting data on pin 3 of a DB-9 or pin 2 of a DB-25 RS-232 connector.

o If your computer is configured as DTE:

Use the supplied RS-232 cable with a Gender changing adapter if necessary. These are available from Radio Shack (Part # 26-243) and other computer stores.

o If your computer is configured as DCE:

You may want to purchase a Null Modem adapter from Radio Shack (Part # 26-1496) or other computer store.

You may also wire your own cable directly to the PK-900's DB-25 connector by wiring the Transmit Data (TXD), Receive Data (RXD), and the Signal Ground (GND) to a DB-25P (Male) connector as diagramed below:

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Computer PK-900 (DB25)

TXD .......................... 2

RXD .......................... 3

GND .......................... 7

o As a default the PK-900 provides XON/XOFF software flow-control to the computer or terminal. The command XFLOW can be turned OFF to enable hardware handshake if your computer requires it. Hardware flow control is achieved with RTS/CTS (pins 4 and 5) of the 25-pin connector on the PK-900's rear panel.

2.6.7 Other Computers with Non-Standard Serial Ports

Computers with non-standard serial ports must meet the following conditions:

o The signal levels must be compatible with RS-232-C. The PK-900 requires the voltage levels from the computer be greater than +3 volts in the "asserted" state and 0 volts or less in the "non asserted" state.

o The signal polarity must conform to the RS-232-C standard. The 0 or negative-voltage state must correspond to logical "1" and the positive-voltage state to logical "0."

o The computer must be able to correctly receive a signal that meets asynchronous RS-232-C specifications. The PK-900 supplies signals that meet this specification.

Make or buy a cable that provides the following connections:

o The computer's serial port signal ground or common pin must be connected to pin 7 of the PK-900's 25-pin connector.

o The pin on which the computer SENDS data must be connected to pin 2 of the PK-900's 25-pin serial connector.

o The pin on which the computer RECEIVES data must be connected to pin 3 of the PK-900's 25-pin serial connector.

If your computer requires any other signals, you must arrange to provide them. The PK-900 has the standard hardware handshake lines available. As a default the PK-900 provides XON/XOFF software flow control to the computer or terminal. The command XFLOW can be turned OFF disabling software flow control and enabling hardware handshake if your computer requires it. The documentation provided with your computer or serial card should clarify any special requirements.

2.7 Terminal (Modem) Software for Other Computers

Any communications program that enables your computer to emulate or act as an ASCII terminal with a telephone modem should work with your PK-900. If you have a familiar program you have used successfully, use it to communicate with your PK-900.

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2.7.1 Terminal Programs for the Apple II, II+, IIe and IIC

The PK-900 operates well with the Apple II family of computers using both Apple-supplied or third-party serial interface cards. Terminal programs include Modem Manager, ASCII EXPRESS PRO, Hayes SMARTCOMM II, and DataCapture 4.0.

2.7.2 Terminal Programs for the Commodore Vic 20

A BASIC communications program is printed in the VIC 20 Programmer's Reference Guide published by Commodore. Use the program listing for "True ASCII"; Commodore computers internally use a modified ASCII format. We suggest you operate your PK-900 at 300 bauds with these computers to avoid possible data speed difficulties.

2.7.3 Terminal Program for the IBM PCjr

The PCjr's BASIC cartridge contains a terminal program. Start the program by typing TERM. Refer to the PCjr's BASIC manual for details on the program. For best results with the PCjr do not run the PK-900's serial port baud rate faster than 1200 bauds.

2.7.4 Terminal Programs for the Tandy Color Computer

Several terminal programs are available for the CoCo. We suggest that you use a commercial program rather than writing your own. The CoCo's "software UART" may be difficult to program in BASIC.

2.7.5 Terminal Program for the Tandy 100/102 and NED 8201

The Model 100, 102 and NEC 8201 have built-in terminal programs in ROM which control the modem and the RS-232C port. Consult the computer documentation for instructions in their use. Make sure that you do not use the program to control the built-in telephone modem.

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CHAPTER 3

RADIO INSTALLATION

3.1 Overview

This chapter describes how to connect the PK-900 to your radio receiver or transceiver. To receive digital transmissions you must connect the receiver audio and Ground to your PK-900. To transmit you will have to add connections to the microphone or low-level transmit audio and to the Push-To-Talk (PTT) circuit of your transceiver.

The most convenient way to connect your transceiver is through a rear panel ACCESSORY Connector (if your transceiver has one). You may also use the Mic connector if you prefer. Appendix E contains connections for many specific radios. MAKE SURE THAT YOU REMOVE POWER FROM THE PK-900 AND YOUR RADIO BEFORE MAKING ANY CONNECTIONS.

3.1.1 Equipment Required

You will need the following for complete transmit/receive connections:

o your PK-900 Data Controller, computer or Computer Terminal and software as discussed in Chapter 2 of this manual;

o AEA-supplied shielded cable for each radio you wish to connect;

o your radio and its power supply;

o microphone or accessory-plug connector(s) required by your radio;

o soldering iron and solder if the radio connectors require it;

o wire cutters and strippers and/or a small pocket knife;

3.2 Receive-Only Radio Connections

If you are a Short Wave Listener (SWL) or only interested in receiving signals, the connections to the PK-900 are simple. Even if you are planning on transmitting and receiving, you may initially want to just receive to become familiar with the PK-900. Taking a little time to tune in and "read the mail" is an excellent way to get acquainted with the various modes before going on the air.

For receive operation, only the audio from the receiver or transceiver (and Ground) needs to be connected to the PK-900. This can often be accomplished by simply connecting the included 3.5 mm audio cable between the PK-900 and your receiver as shown in figure 3-1 below. The audio cable can then be connected to the External Speaker/Earphone jack on the radio you will be using.

NOTE: Some Short Wave receivers come with low-level outputs designed for use with a tape recorder. These outputs typically do NOT have enough level to drive the PK-900.

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Figure 3-1 Receive audio connection to the PK-900.

If you are using an HF transceiver or Short-Wave receiver you should consult Chapter 10 for information on the Signal Identification mode. Chapters 4, 6, 7, 8 and 9 talk specifically about some of the modes you may encounter on the HF and Short-Wave bands.

If you are connecting to a VHF scanner or VHF/UHF transceiver you should look over Chapter 4 on VHF Packet operation.

3.3 Transmit and Receive Radio Connections

To connect your PK-900 to a HF or VHF/UHF TRANSCEIVER you will need access to the Receive-Audio, Transmit-Audio (mic-audio), Push-To-Talk, Ground and optionally a Squelch input for shared voice/data channels. Most of these signals are typically available on the Mic connector and also often on a rear-panel Accessory connector of the transceiver. If you will be wiring the PK-900 to more than one radio, repeat the procedures in section 3.3.5 for each radio you will connect.

3.3.1 Transceiver's Microphone or Accessory Connector?

The most convenient way to connect your transceiver is through a rear panel Accessory connector if one is available. If the PK-900 is connected as an accessory, the microphone used for voice operation can sometimes be left connected to the transceiver. This makes changing between voice and data modes easier than if the microphone must be unplugged in order to connect the PK-900. On most HF radios however, the mic is "hot" and should be unplugged during data operation.

3.3.2 Connections for Specific Transceiver Models

APPENDIX E of this manual contains information and diagrams for connecting the PK-900 to many modern HF and VHF transceivers. Please turn to APPENDIX E and locate the transceiver model you will be connecting to your PK-900. If you do not find the exact model of your transceiver in APPENDIX E, then locate a model from the same manufacturer that has the same Accessory or Microphone connector as the unit you will be connecting.

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3.3.3 Check Your Transceiver's Operating Manual

Locate the Operating Manual for your transceiver and turn to the page describing the connector to which you will attach your PK-900. Even if you found the exact model of your transceiver in APPENDIX E, it is a good idea to verify that your transceiver's manual agrees with the information in the appendix. If the information does not agree, or you could not find the exact transceiver model in APPENDIX E, then you should use the information contained in your transceiver's manual to connect the PK-900.

3.3.4 Specific Connection Points

Whether you are connecting an HF Single Side Band transceiver for RTTY/FAX operation, or a VHF/UHF transceiver exclusively for packet, the minimum connections to your transceiver will be almost identical. HF transceivers have a few optional connections that will be covered after the basic connections have been made.

The following table and figure will be helpful in identifying the proper basic connection points to the PK-900 radio cable.

_______________________________________________________________________________ Wire Pin Signal Name Color Description _______________________________________________________________________________

1 Microphone audio White AFSK from PK-900 to transceiver 2 Ground Brown Audio and PTT common return 3 Push-To-Talk Red PK-900 keys transmitter 4 Receive audio Green Audio from receiver to PK-900 5 Squelch Input Black Allows PK-900 to detect activity on a shared mode channel (optional) Shield/Drain Wire Silver Shield of cable / Microphone Ground _______________________________________________________________________________

Table 3-1 Radio Port 1 and 2 Cable Connections

Figure 3-2 PK-900 to Radio Cable Connections

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3.3.5 Begin Assembling your Radio Cable

Assemble the tools, PK-900 Radio cable and connectors you will need for each radio you wish to connect. You will probably also need a small soldering iron (20-40 watts) and solder at your work area.

3.3.5.1 Prepare the Radio Cable

1. Locate one of the 5 ft PK-900 radio cables included with your PK-900. Note that the Radio cables may have been shipped as a single 10 ft cable which should be cut in half before use.

2. Prepare the bare end of one of the radio cables by removing an appropriate amount of the jacket for the connector you will be attaching. Usually this is 1/2 to 3/4 inch.

3. Carefully remove the foil shield exposing the colored wires underneath. Be careful not to nick or cut the bare shield wire.

4. Strip back 1/8 inch of colored insulation from the GREEN, RED, WHITE and BROWN wires.

NOTE: The BLACK wire is the squelch input and normally not used. The black wire is only needed for Packet operation if the channel you plan to operate on is used for both voice and data. If you need this connection, strip away 1/8 inch of BLACK insulation as done with the other four wires. If this wire is not needed, then leave the insulation intact.

3.3.5.2 Verify the Connection Points with Your Manual

Look at the connector closely (with a magnifying glass if necessary) and locate pin 1. Compare this to the location of pin 1 on the connector drawing in your transceiver's manual and also in APPENDIX E. This is important as some diagrams show the connector from the inside of the transceiver, not the outside of the plug you are wiring. This will help insure that the plug is not wired backwards.

3.3.5.3 Prepare the Connector

Now that the cable is prepared, you are ready to prepare the connector for wiring. If the connector you are wiring has a shell, be sure that it is placed over the cable before any connections are made. If this is not done, an otherwise perfect wiring may have to be redone.

3.3.5.4 Wire the Connector

The following connections must be made for transmit and receive operation of the PK-900. Refer to table 3-1 and figure 3-2 as well as APPENDIX E and your transceiver's manual when making these connections.

HINT: When wiring a Connector, it is often easier to wire the inside or middle connections first and work your way to the outside pins. For this reason the following steps are not numbered and may be done in any convenient order.

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o Connect the Shield/Drain wire (Silver wire with no insulation) to the Microphone GROUND connection if your transceiver has one. If your transceiver does not have a separate Microphone or Audio in Ground connection, then this wire should connect to the single Ground along with the Brown wire. See the next step.

o Connect the BROWN wire to the main GROUND on the connector. This Ground is the one used for the PTT and receive audio. You should connect the Silver Shield/Drain wire to this GROUND only if there is not a separate Microphone Ground as described in the previous step.

o Connect the RED wire to the Push-To-Talk (PTT) terminal on the connector. At this time, check the manual to determine whether your transceiver uses positive (+) or negative (-) PTT. The PK-900 comes from the factory set for Positive PTT since most transceivers use this method of keying. This will be discussed in more detail in the Adjustment sections below. If you are connecting a Handheld transceiver to your PK-900, you will probably need a resistor and/or capacitor to isolate this connection from the AFSK audio. Check APPENDIX E.

o Connect the WHITE wire to the MICROPHONE AUDIO terminal on the connector. This connection carries the low level Audio Frequency Shift Keying (AFSK) to the transmitter's microphone audio section. If you are connecting a Handheld transceiver to your PK-900, you will probably need a resistor and/or capacitor to isolate this connection from the PTT. Check APPENDIX E.

o Connect the GREEN wire to the RECEIVER AUDIO terminal on the connector. For the PK-900 to operate properly, we recommend at least 200 mV RMS of receive audio be available. If you are connecting to an Accessory Jack, make sure the available level is at least 200 mV RMS. For CW work 400 mV may improve operation.

o If you will be using a Packet Radio channel that is shared with voice users then you should connect the BLACK wire to the SQUELCH status pin of the connector. This will prevent the PK-900 from transmitting when there is a received signal strong enough to open the Squelch. If you connect this pin you may have to change the setting of the SQUELCH command in the PK-900. Most VHF/UHF Packet channels are no longer shared with voice users so this connection will probably not be needed.

This completes the minimum necessary connections for transmit and receive operation with the PK-900. If you are interested in using the PK-900 to transmit Morse code (CW) or transmit RTTY using FSK inputs on your HF transceiver, the following three sections (3.3.6 and 3.3.7) should be read.

If you will not be using any of the connections described in the following sections, then skip ahead to the Final Adjustment section

3.4 where you will set levels and prepare to go "On the Air".

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3.3.6 Wiring Your HF Transceiver for Direct CW Keying

The PK-900 can directly key CW with HF and VHF multi-mode transceivers. This requires that a cable be wired from the CW KEY OUT jack on the PK-900's rear panel to the CW keying input of your transceiver on the correct Radio Port. Refer to the instructions below and Figure 3-3 to wire the PK-900 side of the cable.

Figure 3-3: Direct CW Keying Cable diagram

1. Locate a 5 pin DIN connector from the PK-900's accessory bag.

2. Consult your radio's instruction manual to determine if your radio uses negative (Grid Block) or positive keying polarity. Locate some shielded audio cable from Radio Shack or other cable house and solder the DIN connector to the cable as shown above.

3. Locate the connector for the CW keying input to your transceiver. These are often supplied in your transceiver's accessory kit.

4. Wire the transceiver connector as per the instructions in your transceiver's manual for a "Straight key".

Connect the shielded cable you just wired from the PK-900's positive or negative keying output to your radio's CW key input connector. See the Specifications on page 1-4 for maximum limits.

3.3.7 Connections for Direct FSK Operation on RTTY

Some HF SSB radios provide direct FSK (Frequency-Shift Keying) for RTTY operation. Direct FSK can be an advantage when using RTTY and AMTOR and can sometimes help in HF packet operation. FSK operation may be helpful if your transceiver can switch in filters. Be cautious of narrow filters as they can limit your data rate. Direct FSK is not always recommended for data speeds above 110 bauds. Consult your transceiver's manual for further recommendations on direct FSK.

To install and operate your PK-900 and radio in the FSK mode:

1. Connect a shielded cable from the PK-900's FSK receptacle, pins 1 or 4, to the radio's FSK input for radio port 1. Pins 3 or 5 are the FSK outputs for radio port 2.

NOTE: Polarity of the FSK signals is not standardized by the radio manufacturers. We have observed that Icom radios most often use FSKN (pins 3 and 4), while Kenwood radios most often use FSKR (pins 1 and 5). Consult your transceiver's manual to identify the proper polarity.

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2. Connect the FSK lines from the PK-900 to your radio's FSK or RTTY input in accordance with your radio's requirements.

See Figure 3-4 below.

Figure 3-4 FSK Connector Connections

NOTE: When using FSK, the same power and duty cycle limits apply as cited earlier for AFSK operation. Consult your radio's operating manual for any power or transmit time limits.

3.4 PK-900 Configuration Jumpers and Connections

Before operating the PK-900, you must first make sure it is correctly configured for your radio's PTT. After this has been checked you should then connect the cables you constructed above.

3.4.1 Push-To-Talk (PTT) Configuration

Before you connect the radio cable(s) you just made to the PK-900, consult your transceiver's manual for Push-To-Talk keying polarity. Most transmitters and transceivers made in the last 15 years use Positive PTT keying. However some gear, especially if it contains vacuum tubes, may use a negative PTT keying voltage.

The PK-900 is configured for positive PTT at the factory so it will operate with most equipment without changes. However, if necessary, you can change the polarity of the PTT configuration on either Port 1 or Port 2. Follow these steps:

o Remove four screws from the top of the PK-900 chassis cover and lift off the cover.

o Locate Jumper posts JMP1 and JMP2 which are about 4 inches in from the right-rear corner of the PCB.

o JMP1 configures Port 2 and JMP2 configures Port 1.

o When the shorting jumpers are towards the fuse, the port is configured for Positive (+) PTT. When the shorting jumpers are towards the center, the port is configured for Negative (-) PTT.

Replace the cover and four screws when you are finished configuring the polarity of the PK-900 PTT circuit.

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3.4.2 PK-900 Connections

Remove power from the PK-900, your transceiver and all accessories before making any connections.

Connect the radio cable(s) you constructed in section 3.3.5 between a Radio port on the PK-900 and your transceiver(s).

If you wired cables for CW keying or Direct FSK then connect these to the appropriate point on your equipment.

3.5 Transceiver Adjustments

This section is split into separate procedures for FM and SSB radios. You may adjust either port at any time without affecting the other.

3.5.1 FM Transceiver Final Adjustments

1. Turn on your computer and PK-900 and start your terminal program.

2. Connect the radio to a dummy load. Be prepared to monitor your transmissions with another nearby radio such as a handheld transceiver.

3. Verify that your PK-900 and FM radio are connected as shown in Figure 3-5 below.

Figure 3-5 Radio-to-PK-900 Connections

4. If you are using an AEA program such as PC-PAKRATT II or MACRATT, you must enter the Dumb Terminal mode to access the CALIBRATE Mode as described below.

5. Enter the Calibrate mode by typing: "CAL <Enter>."

NOTE: In the Calibrate mode only, the "K" key toggles the transmitter PTT line on and off. The "SPACE BAR" toggles the PK-900's tone generator from "Mark" (the lower pitched tone) to "Space" (the higher pitched tone). The PK-900 has a transmit watchdog timer circuit that unkeys your transmitter automatically after sixty (60) seconds. As you perform the following adjustments, unkey periodically, then rekey the transmitter by typing "K."

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6. Press the "K" key on the keyboard to key the transmitter. You should hear a continuous tone in the monitor receiver.

7. Tap the space bar several times until the higher pitched of the two tones ("Space") is heard.

8. Refer to the figure below of the PK-900's rear panel and locate the AFSK TX level potentiometer adjustment for the radio port you are calibrating.

Figure 3-6 PK-900 Rear Panel AFSK TX level Controls

9. With the PK-900 keying the transmitter and sending the higher of the two tones, adjust the transmit audio level for the port you are calibrating as follows:

o Listen to the monitor receiver; turn the PK-900's rear panel AFSK Output Level adjustment screw clockwise (CW) until you hear no increase in output level in the receiver.

o Rotate the AFSK Output Level adjustment screw counterclockwise (CCW) until the audio signal on the monitoring receiver is slightly but noticeably reduced from the maximum level. This is the proper AFSK level setting.

NOTE: If you find the "correct" AFSK level setting occurs in the first 20% of the potentiometers range, the adjustment may be difficult. If you find this adjustment difficult, the internal AFSK level jumper may be moved to the LOW setting which will improve the adjustment range of the potentiometer.

To locate the internal AFSK level jumpers in the PK-900, remove the four screws that secure the top chassis, and carefully remove it by lifting straight up.

Look for jumpers JP5 and JP6 near the radio port connectors at the rear of the PK-900 as shown in figure 3-7 below.

Jumper JP6 controls the output level of radio port 1, and jumper JP5 controls the output level of port 2. When the jumper is towards the front, the output level is HIGH. Move the jumper for the radio port being adjusted to the rear two pins to set the AFSK output level to LOWer range. Repeat step 9 when this has been completed.

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Figure 3-7 PK-900 AFSK HI/LOW Level Jumpers

10. Type "K" to return to receive mode.

11. Type "Q" to "Quit" (exit) the calibration routine.

You've now set your FM transmitter's deviation to an approximate level which will be adequate for operation.

12. With your radio in the receive mode, open the squelch control so that a steady hiss or noise is heard on a speaker.

13. If using radio port 1, set the receiver's volume control to a comfortable listening level. With the receiver unsquelched but with no signal present, adjust the THRESHOLD control so the DCD LCD on your PK-900 just lights. This is the approximate proper level for best receive performance from your PK-900's modem. If using radio port 2. Normal listening levels will activate the DCD with received signals.

14. Reset your receiver's squelch control for normal operation.

3.5.2 SSB Transceiver Final Adjustments

Digital modes with an SSB radio require some different settings of the radio's operating controls for proper AMTOR and packet operation. Be sure to observe the following setting recommendations:

o Set VOX to OFF. o Set speech compression to OFF. o Set AGC to FAST (if available). o If you wish to use an external RF amplifier in AMTOR, PACTOR or Packet, disconnect the ALC cables between your SSB radio and the external RF amplifier.

Remember - Baudot and ASCII RTTY and Mode B (FEC) AMTOR are continuous key-down conditions - Your radio's duty cycle is 100% for the duration of each transmission. If your SSB radio isn't designed for continuous full-power operation, you must operate your radio at reduced output power. Consult the manufacturer's specifications for details on the operating duty cycle.

NOTE: Make all connections with all power off.

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1. Connect your PK-900 and SSB radio as shown in Figure 3-5.

2. Turn on your PK-900 and your computer and start your terminal program.

3. Connect your SSB radio to a dummy load.

4. If your SSB radio has a "monitor" facility, i.e., an audio output that lets you listen to the audio signals entering the microphone or phone patch jacks, turn that monitor circuit on.

5. Set the radio's MODE selector to LSB (lower sideband).

6. Set the radio's meter switch to the "ALC" position. If the radio doesn't have an "ALC" indication, set the meter switch to "Ip" or "Ic" to read plate/collector current. If a current reading isn't available, set the meter to indicate power output.

7. If you are using an AEA program such as PC-PAKRATT, COM-PAKRATT or MACRATT, you must enter the Dumb-Terminal mode (see program manual) to access the CALIBRATE Mode described below.

8. Enter the Calibrate mode by typing: "CAL <Enter>."

NOTE: In the Calibrate mode only, the "K" key toggles the transmitter PTT line on and off. The "SPACE BAR" toggles the PK-900's tone generator from "Mark" (the lower pitched tone) to "Space" (the higher pitched tone). The PK-900 has a transmit watchdog timer circuit that unkeys your transmitter automatically after sixty (60) seconds. As you perform the following adjustments, unkey periodically, then rekey the transmitter by typing "K."

9. Adjust the transceiver's Microphone Gain control to its minimum setting.

10. Press the "K" key on the keyboard to key the transmitter. Increase the transceiver's microphone gain control until you hear a continuous tone in the radio's monitor output.

11. If you are able to hear the tones in radio's speaker, tap the space bar several times until you hear the lower pitched of the two tones ("Mark").

12. With the PK-900 keying the transmitter and transmitting the lower of the two tones, adjust the transmit audio level as follows:

I. Rotate the microphone gain control clockwise (CW) approximately in the one-quarter ON position. You may also set it to the position used for SSB operation.

II. Turn the PK-900's rear-panel AFSK Output Level adjustment screw clockwise (CW) until the ALC meter shows a small deflection from the unmodulated reading. Check the radio's plate/collector current or output power indicators.

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III. Adjust the AFSK Output Level control until the radio's indicators show approximately thirty percent (35%) of the manufacturer's rated full-power reading.

EXAMPLE: If the manufacturer's plate/collector current specification for CW operation is 200 mA, set the AFSK Output Level control and your microphone gain control so that the plate/collector current indicates 75 mA.

IV. Your radio may be able to operate at higher output levels. Consult your radio manual.

NOTE: If you find the "correct" AFSK level setting occurs in the first 20% of the potentiometers range, the adjustment may be difficult. If you find this adjustment difficult, see the NOTE in step 9 of the FM adjustment section on page 3-9 of this manual. Repeat step 12 when this has been competed.

13. Type "K" to return to receive mode.

14. Type "Q" to "Quit" (exit) the calibration routine.

You have now set the PK-900's transmit audio output level and your SSB radio's microphone gain control to an approximately correct level for all operating modes.

NOTE: For packet radio operation, the radio's microphone gain control can be adjusted to produce the full output power recommended by the radio manufacturer. Packet is a "bursty" mode and the transmitter is keyed on and off automatically by the PK-900. The resulting duty cycle is much less than 100% and full-power operation is generally acceptable.

15. With your radio in receive mode, tune the receiver to a clear, unoccupied frequency.

16. Set the receiver's audio volume control (AF GAIN) to the position you would normally use for CW reception. This is the approximate receiver audio output level for best receive performance from your PK-900's modem.

3.6 Oscilloscope Connections

Some operators prefer to use an oscilloscope for tuning. Radio port 1 provides mark and space outputs for driving the vertical and horizontal inputs of an oscilloscope as shown below.

Figure 3-8 PK-900 Oscilloscope Connections

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CHAPTER 4

PACKET RADIO

4.1 Overview

In the last several years Packet has grown to become perhaps the most popular digital mode on the amateur bands. Although Packet can be found on HF (primarily on the 20 meter band) it is most popular on the VHF and UHF FM bands. This chapter will start with general Packet operation and then discuss VHF and UHF Packet. Packet on the HF bands requires some special considerations, so we will leave it until the end of this chapter.

Your PK-900 can operate HF or VHF Packet (on Radio port 2) and any other digital mode on Radio port 1 at the same time. This feature can come in handy allowing you to keep an "ear" on local packet activity while operating on any of the other digital modes normally found on HF. Sorting out the data from both Radio ports also requires some special considerations and will be discussed later in the chapter after HF Packet operation has been covered.

4.1.1 Getting Started

You can learn quite a bit about Packet operation with the PK-900 before even connecting it to a transceiver. For your first packet practice, the PK-900 will be connected in a "loopback" circuit as done in the "Quick Check" performed in Chapter 2. In this configuration, the PK-900 will "talk to itself" which allows you to become familiar with packet before actually going on the air.

4.1.2 Making the Loopback Connection

Make sure the PK-900 is turned OFF and power is removed before performing one of the following.

I Locate the WIRE "Loop-back" jumper and insert it into pins 1 and 4 of the RADIO-1 connector on the PK-900 rear panel.

II If you cannot locate the wire "Loop-back" jumper and have a spare Radio cable, you may construct the following:

1. Get the unused Radio Cable mentioned in Chapter 3.

2. Strip about 1/4 inch of insulation from the Green and White wires at the "radio" end of the cable.

3. Join the Green and White wires by twisting them together gently.

4. Insert the 5-pin DIN connector end of the cable into the "RADIO-1" connector on the PK-900's rear panel.

5. Go on to section 4.2.

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4.2 Packet Introduction

You've now connected your PK-900's transmit audio output to its receive audio input. Your PK-900 can now "talk to itself" in packet.

1. Set the rear-panel AFSK level control for RADIO-1 at 50% (straight up and down) for the following Packet introduction.

NOTE: If you have adjusted the RADIO-1 rear-panel AFSK level control for a particular transceiver in chapter 3, then mark this setting with a pencil so it can be reset when finished.

2. Turn on your computer. Load and run your communications program.

If you are using an AEA PAKRATT Program, follow the program manual's instructions to enter the Packet mode on Radio Port 1, and then skip to step 4.

If you are using another Computer program or a Terminal, set the communication parameters as done in Chapters 2 and 3.

3. Press the PK-900's front panel power switch to the ON position if you have not already done so.

You should notice the sign-on message seen in chapter 2. The LCD Status display should indicate you are in the Packet mode.

4. After you have seen the sign-on message and/or entered the Packet mode, you must enter your own callsign (with the MYCALL Command) if you are to converse with any other Packet stations. If you try to connect to a station without entering your call sign, your PK-900 will send you the following message:

?need MYcall

If you are an SWL and do not intend to transmit, you should enter "AAA" as a Callsign (MYCALL).

If you are using an AEA PAKRATT program, follow the instructions in the Program Manual to enter your callsign. If you are using a terminal or terminal emulating program on your computer, you must use the MYCALL command to install your call sign.

Note that since the PK-900 has two radio ports, you must enter a callsign for each port. The callsigns may be the same, or can be different to make life a little easier in the "two Ham" family. You must change the callsign from the default "PK900" on each radio port, or that port will not transmit packets. For example, if your Callsign is WX2BBB, enter the following:

cmd:MYCALL WX2BBB/WX2BBB <Enter>

The PK-900 will respond with:

MYcall was PK900/PK900 MYcall now WX2BBB/WX2BBB

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Both Packet radio ports will now assume the callsign WX2BBB.

5. If you are using an AEA program follow the instructions in the Program manual to CONNECT in packet mode to your own callsign (the one you just entered in MYCALL).

If you are using a Computer Terminal or a non-AEA program, entering the following after the "cmd:" command mode prompt will cause the PK-900 to Connect to yourself:

CONNECT (your callsign) <Enter>

After pressing <Enter>, you should observe the RADIO 1 TX LCD and DCD LCD light briefly, and the TUNING bar graph spread. After a few moments, your monitor should display:

*** CONNECTED to (your callsign)

Notice that the front panel RADIO 1 Connect LCD shows CONNECTED. You may also notice that the CONVERSE LCD is also on indicating that the PK-900 is ready to CONVERSE with the station (in this case it is yourself).

This is how a packet connection is established. Whether you are "Connecting" to another Amateur, a Packet Bulletin Board System (PBBS) or a Networking Switch (more on this later) this initial procedure must be used to establish each and every Connection.

6. Type a few characters to yourself such as "Hello this is my first packet Connect. My name is ..." then press the <Enter> key.

Shortly after pressing the <Enter> key, you should see the message you typed reappear on your screen. If you had connected to a distant station, they would have seen the message you typed appear at nearly the same time.

7. After you have typed a few lines (packets) to yourself, you will probably want to end the connection or "DISCONNECT". If you are using an AEA program, follow the instructions to DISCONNECT from the packet station you are talking to.

If you are using a Computer Terminal or a non-AEA terminal program, the following will cause the PK-900 to DISCONNECT:

Enter <CONTROL-C> (hold down the Ctrl and then type the letter C). Your monitor should respond with the command prompt:

cmd:

Enter the following: D <Enter>. Your monitor should respond with:

cmd:*** DISCONNECTED: (your callsign) p1 (your call)*>(your call) (UA)

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Note that the front panel CONNECT LCD will change to DISCONNECTED indicating that you are no longer connected.

8. You have just done the three things necessary in any Packet QSO.

o You started the QSO (with yourself) by CONNECTing. (Step 5) o You sent some information (to yourself) and then received the information that you sent. (Step 6) o You then ended the QSO by DISCONNEcting. (Step 7)

Repeat steps 5, 6 and 7 above until you feel comfortable with Connecting, exchanging information and Disconnecting. These operations will be performed each time you use Packet so they should be second nature to you before going on the air.

When you feel comfortable Connecting, sending information and Disconnecting, you are ready to start listening to VHF packet.

9. Turn OFF and remove power from the PK-900.

o Return the Port 1 rear-panel AFSK level potentiometer to the setting you marked in Step 1, if any.

o Remove the "Loop-back" jumper from the RADIO-1 port and reconnect your transceiver or receiver set-up in Chapter 3.

4.3 VHF/UHF Packet Operation

We will first listen to (and watch) some of the VHF or UHF Packet activity in your Local Area. This will allow you to become a little better acquainted with packet in your area before going "On The Air".

1. Construct a Radio Cable for the VHF/UHF transceiver you intend to use for Packet as described in Chapter 3 and connect your transceiver to the RADIO-1 connector on the PK-900 rear panel.

2. Load and run your communications program and enter the Packet Mode as done in the Packet Introduction section above.

3. Set Radio Port 1 for VHF Packet operation (default) as follows.

If you are using an AEA program, follow the instructions to select the VHF modem on Port 1 by turning the VHF Parameter ON, this will automatically set the radio baud rate HBAUD to 1200.

If you are using a Computer Terminal or a non-AEA terminal program, the following sets the VHF mode of the PK-900:

Type <CONTROL-C>. (Type C while pressing the <Ctrl> key down.) Your monitor should respond with the command prompt:

cmd:

Then enter VHF ON <Enter> Your monitor should respond with:

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Vhf was OFF/ON Vhf now ON/ON

Then enter HB 1200 <Enter> Your monitor should respond with:

HB was 300/1200 HB now 1200/1200

4. Turn ON your VHF or UHF FM transceiver and tune to a known packet channel in your area. Most packet operation is on simplex, so the repeater offset on your transceiver should be disabled. If you know there is packet in your area, but do not know the frequency, you should try some of the following frequencies:

2 meter (144 MHz) band:

145.01 MHz, 145.03 MHz, 145.05 MHz, 145.07 MHz, 145.09 MHz

144.99 MHz, 144.97 MHz, 144.95 MHz, 144.93 MHz, 144.91 MHz

1-1/4 meter (220 MHz) band:

223.40 MHz, 223.42 MHz, 223.44 MHz, 223.46 MHz, 223.48 MHz

70 cm (440 MHz) band:

440.975 MHz, 441.000 MHz, 441.050 MHz, 441.025 MHz, 441.075 MHz

You know you've found a packet channel when you hear the characteristic "Braaaaaap" sound of packet transmissions.

5. Once you've found an active packet channel, you must make sure you have enough receive audio (volume) from your transceiver to light the DCD LCD on the PK-900 when a packet is being received. If the DCD LCD does not light when packets are received, either there is not enough receiver audio or the Threshold control is turned too far counter clockwise.

You must also make sure that the DCD LCD goes out when no packet signals are present on the channel. If the DCD LCD does not go out when the channel is clear, make sure the Squelch control on your transceiver is set high enough to silence the speaker. If the DCD LCD stays on when the packet channel is quiet, your PK-900 will not send packets to other stations.

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4.3.1 What You Should See

If all is operating properly, you should see some packets on your screen. Some typical packets you might "Monitor" are shown below:

p1 N7ALW*>WA7GCI [C] p1 WA7GCI*>N7ALW (UA)

p1 K6RFK>N7ALW*>N7GMF: Goodnight John, its been nice talking to you.

p1 N7ALW*>WA7GCI: Hi Bob, how are you this evening?

p1 KD7NM*>MAIL: Mail for: K6RFK N7ML

p1 N7HWD-8*>ID: NET/ROM 1.3 (SEA)

p1 SEA*>N7ML: SEA:N7HWD-8> Connected to #SEA:N7HWD-7

p1 K6RFK>N7ALW*>N7GMF [D] N7GMF>N7ALW*>K6RFK (UA)

NOTE: You will probably see data (Packets) on the tuning bar-graph which do not print on the screen. This is normal and is a function of the MONITOR and the MPROTO commands.

4.3.2 What It Means

There are different types of packets that mean different things to the PK-900. Your PK-900 keeps track of and knows what to do with the packets so users need not be concerned with them most of the time. Since the PK-900 can "Monitor" all Packet activity on a channel, we'll briefly discuss the types of packets you will most often see. Skip to the next section if you do not plan on doing much monitoring.

Let's look at the first packet in the examples above and get acquainted with what it all means.

p1 N7ALW*>WA7GCI [C]

The first two characters in monitored packets represents which radio port "heard" the packet and will be either "p1" or "p2". Every single packet you send will have your callsign (the one you just entered in MYCALL) as the first callsign of the packet. The callsign after the ">" is the next station the packet will go to. So the packet listed above originates from N7ALW and is being sent to WA7GCI. All packets will have at least these two callsign fields.

The "[C]" immediately following the two callsigns identifies this packet as a CONNECT Request. So we see that N7ALW is requesting a packet CONNECTION with WA7GCI.

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The second packet in the above examples is a response to the first.

p1 WA7GCI*>N7ALW (UA)

In this case we see that WA7GCI is sending to N7ALW by the order of the callsigns. This packet acknowledges the Connect request as shown by the "(UA)" which stands for Un-numbered Acknowledge.

One benefit of packet radio is that packets can be relayed or "digipeated" by stations on the same frequency. In fact, packets can be relayed by up to eight stations to reach a distant station that cannot be heard directly. In practice, digipeating through many stations does not work very well, but you will often see packets digipeating through one or two stations to reach their destination. The packet shown below is an example of a digipeated packet.

p1 K6RFK>N7ALW*>N7GMF: Goodnight John, its been nice talking to you.

This packet originated from K6RFK and is being sent to N7GMF but is "Digipeated" through the station N7ALW. We also see that this packet contains data by the text "Goodnight John...". Another thing that should be noticed in this packet is the asterisk (*) in the first line. The asterisk tells which station was actually heard sending the packet. In this case, we can see that we actually heard the digipeating radio station N7ALW. Without the asterisk, we could not tell whether the transmission came from radio station K6RFK or N7ALW. More will be discussed about digipeating later, but the above example is typical.

The following packet is a data packet from N7ALW to WA7GCI.

p1 N7ALW*>WA7GCI: Hi Bob, how are you this evening?

Remember that in the first example we saw the two stations Connect. Now that they are connected, they may exchange data packets.

The following packet is a Beacon packet from KD7NM. Since we see the packet is addressed to "MAIL" we know KD7NM is probably a Packet Bulletin Board System (PBBS).

p1 KD7NM*>MAIL: Mail for: K6RFK N7ML

The data section of this packet says "Mail for: K6RFK N7ML". This Beacon lets people know that K6RFK and N7ML have mail waiting on the KD7NM PBBS without having to connect.

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The following Beacon packet is intended as identification for a NET/ROM level-3 packet networking switch.

p1 N7HWD-8*>ID: NET/ROM 1.3 (SEA)

In this case, the Packet Switch is using the callsign N7HWD-8, but also uses the alias SEA as a callsign. There are many types of Packet Switches now in use, but NET/ROM is one of the most popular. We will briefly discuss using a NET/ROM switch later in this chapter since most switches operate in much the same way.

The packet below was sent by the network switch SEA to N7ML.

p1 SEA*>N7ML: SEA:N7HWD-8> Connected to #SEA:N7HWD-7

The packet above from SEA contains the data "SEA:N7HWD-8> Connected to #SEA:N7HWD-7". This message tells N7ML that he is now connected to another port on the SEA Node named #SEA. Again, we will talk more about how and why N7ML might want to do this later in the chapter.

The following packet is again from K6RFK to N7GMF and is being digipeated through N7ALW. This packet indicates that K6RFK is finished talking to N7GMF and wants to Disconnect. Again we see that we are not hearing K6RFK, rather we are hearing N7ALW as indicated by the asterisk (*) after the callsign.

p1 K6RFK>N7ALW*>N7GMF [D]

The following packet is an acknowledgment (or simply called an ACK) that lets K6RFK know that N7GMF has acknowledged the Disconnect request sent above. K6RFK and N7GMF are no longer Connected.

p1 N7GMF>N7ALW*>K6RFK (UA)

As can be seen, all of the above examples were heard on radio port 1 of the PK-900. If a second radio was connected to radio port 2, we would have seen some monitored packets prefaced with a "p2" as well. See section 4.8 for more information on controlling both radio ports when you are ready.

NOTE: Some applications software such as PB and PG for Amateur Satellite use have problems with the port designators "p1" and "p2" in front of monitored packets. To disable the port designators "p1" and "p2" from appearing turn OFF User Bit 19 (UBIT 19) by typing "UBIT 19 OFF <Enter>" at the command prompt.

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4.3.3 What Happens When You Connect

If you are working with a friend who is familiar with packet, you may want to skip to section 4.4. If you are on your own, the following three sections will help you learn what to expect on VHF/UHF packet.

There are three different kinds of packet stations you are likely to encounter in your first Connects: Standard TNCs, Mailbox Systems and Network Switches. The following sections discuss each station type.

4.3.3.1 Standard TNCs

When you first turn on your PK-900, it becomes a standard AX.25 packet TNC (Terminal Node Controller). All TNCs and Multimode controllers have this capability. When you Connect to a TNC, in most cases you will be connecting directly to someone's computer screen. If you see an automatic Connect Message (CMSG) similar to the one below, you know you have reached a TNC.

Welcome to my packet station. If I don't respond, please leave a message and Disconnect.

If you get a message like this when you connect to another station, usually you would type something like "Are you there?". If you do not see a response from the other station in a minute or so, simply leave a message - just like a telephone answering machine.

The TNC at the other station should then hold your message until the operator returns to his computer. Later we will discuss how your PK-900 can do the same for messages it receives from others.

4.3.3.2 Mailbox Message Systems

Although Standard TNCs allow incoming messages to be saved, there is no way for the owner to leave a message for someone who will connect at a future time. The ability to both send and receive messages without the owner being present is accomplished by a Mailbox.

There are many different Packet Mailbox systems in use. Some systems are large and require the use of a dedicated computer. Other systems are small like the personal MailDrop built into your PK-900.

Large systems are often called Packet Bulletin Board Systems (PBBS) since they serve as electronic message centers for a local area. PBBS's are a source of information as well as a gateway for messages that can be sent to and received from other parts of the country or world. You will probably want to locate the local area PBBS nearest you and connect to it from time to time.

Mailbox systems are easy to use and most operate in much the same way. Most Mailboxes and other automatic systems usually have Help available by sending an "H" or "?". If you connect to a Mailbox such as a PK-900 MailDrop you will see something like the following:

*** CONNECTED to KD7NM [AEA PK-900] 17480 free (A,B,H,J,K,L,R,S,V,?) >

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If you get something like this when you connect to another station, try typing an "H" or a "?" to get a help list as shown below:

A(bort) Stop Read or List B(ye) Log off H(elp) Display this message J(log) Display stations heard K(ill) K n: Kill message number n KM : Kill messages you have read L(ist) L : List message titles LM : List messages to you R(ead) R n: Read message number n RM : Read all your unread messages S(end) S : Send a message to SYSOP S n: Send a message to station n ? Same as H(elp) [AEA PK-900] 17480 free (A,B,H,J,K,L,R,S,V,?) >

There are quite a few options available on the MailDrop, but the most commonly used commands are L(ist), R(ead), S(end) and K(ill) message.

For example, you may first want to LIST all the messages that are available on a mailbox that you connect to. This is done by simply sending "L" or "LIST" command to the system you have just connected.

If you are interested in any of the message subjects that appear, you may then READ the messages that interest you. To read a message, simply send the command "R (message number)", where (message number) is the number of the message you are interested in.

After you are finished reading messages, you may want to SEND a message to the SYSOP (short for System Operator) or to another user. To send a message simply enter "S (callsign)" where (callsign) is the call of the station you are sending the message to.

When you are finished Listing, Reading and Sending messages, you will want to send the Bye command to log-off (disconnect) from the Mailbox.

Feel free to experiment with Mailboxes and other packet systems. Remember that most automatic systems will send you help on commands if you send an "H" or "?". For more information on setting up and using your own PK-900 Maildrop, see Chapter 5 on MailDrop Operation.

4.3.3.3 Packet Switches and "Nodes"

When Amateur Packet radio was first beginning there were not many stations on the air. Amateurs at that time "digipeated" through many stations (up to 8) to connect to others over long distances. As more users became active on packet, digipeating quickly proved to be an inefficient way of relaying packets through even a very few stations.

To solve this problem, Amateurs began working on more efficient "higher level" ways of routing packets over long distances. NET/ROM (tm), ROSE, TCP/IP and TEXNET are some of the higher level protocols that emerged and are currently in use around the world.

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NET/ROM, developed by Software 2000, quickly became a standard that others imitated. Many networking "Nodes" today use a similar if not identical set of commands. We will discuss the typical NET/ROM commands you will likely encounter when connecting to a packet switch.

When you connect to a NET/ROM Node you will not initially get any prompt. Since NET/ROM commands are few and easily memorized, they did not see a need to clutter the channel with prompts. Like other automatic systems however, if you send an "H" or a "?" for Help you can expect to get a "Help" response similar to the following:

SEA:N7HWD-8> Invalid Command (CONNECT INFO NODES ROUTES USERS)

In our example, the line above is from the Seattle node, simply known as SEA. The callsign for the node is N7HWD-8. "Invalid Command" means that the node did not understand the command you sent, so it returned the above "help" line to remind the user of the commands it knows. These are CONNECT, INFO, NODES, ROUTES and USERS.

Most often you will use the nodes CONNECT command to connect to other stations. Once you have connected to the node, simply send the command "CONNECT (callsign)" or simply "C (callsign) where (callsign) is the call of the packet station you want to connect to that is in range of the node.

Not everyone you want to talk to is in range of your local Node. Fortunately, NET/ROM will learn about other nodes it can reach and allow you to connect to these nodes as well. To find out what other nodes your local station can reach, simply type the command "NODES" after you connect. This will display something like the following:

SEA:N7HWD-8> Nodes: BALDY:WB6VAC-8 BOI:W7SC BOISE:N7FYZ-8 COE:KK7X-4 ELN:N7HHU-8 EVT:KA7VEE-8 LSO:K7ZVV-8 MCW:WB7DOW-12 MSO:W7DVK-5 OLY:K7APT-8 PDT:N7ERT-5 PDX7:KA7AGH-8 PTN:K7TPN-8 RLIMB:W0RLI-2 SALEM:AF7S-1 SEAW:N8GNJ-8 SPOKN:WB7NNF-8 SVBBS:KA7RNX TAC:W7DK-8 YKM:K3GPJ-8

When you connect to a node (either directly or through another node) you may want to know who else is using that particular node. Type the command "USERS" to find out who is using the system. You will see your own call in the list as well as anyone else who is using the node. An example is shown below:

SEA:N7HWD-8> NET/ROM Version 1.3 (662) Uplink(W7MCU) <--> Downlink(W7MCU-15 WA7ZUE) Circuit(SEAW:N8GNJ-8 KA7RZK) Uplink("your callsign")

The IDENT command simply sends you an identification packet from the node that may give its location and owner as shown below:

SEA:N7HWD-8> NORTHWEST AMATEUR PACKET RADIO ASSOCIATION

145.01 MHZ, USER LAN, GRASS MTN. Local BBS is N7HFZ

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The ROUTES command provides routing information about other nodes that can be reached.

A complete discussion of NET/ROM is beyond the scope of this manual, but we hope the above information will help get you started. Certainly the CONNECT, NODES and USERS commands will allow you to navigate through the network, and find new people to talk to.

4.3.4 Who Can I Talk To?

Now that you understand a little about the different packets and packet stations, you are ready to make your first real connection.

If you do not have a friend on Packet in your local area, then you will want to choose a station you can reach. Fortunately the PK-900 has a command called MHEARD that displays the list of the 18 most recently heard stations. Check this list in one of the following ways:

I If you are using an AEA PAKRATT program, follow the instructions in the program manual for checking the Packet MHEARD list.

II If you are using a Terminal or Terminal Program on your computer, then first type a <CTRL-C> to make sure you are in the PK-900 Command (cmd:) mode. Then type the command MHEARD as shown. You should then see a display similar to the one below.

cmd:MHeard

........ p1 N7GMF

........ p1 K6RFK

........ p1 SEA*

........ p1 N7HWD-8*

........ p1 KD7NM*

........ p1 N7ALW*

........ p1 WA7GCI*

cmd:

The callsigns in the list are the stations heard by your PK-900 with the most recently heard station at the top of the list. As in the Monitored packets, the asterisks (*) indicate that the station was heard directly by the PK-900. The callsigns without an asterisk were relayed by another station and so cannot be connected to directly. The "p1" means the station was heard on radio port 1.

4.3.5 Your First Real Connect

Choose one of the stations with an asterisk displayed in YOUR MHEARD list, or a friend that you know is "on the air" near to you.

If you are using an AEA PAKRATT program, follow the instructions to CONNECT in Packet mode to the callsign you chose above.

If you are using a Computer Terminal or a non-AEA program, entering the following after the "cmd:" command mode prompt will cause the PK-900 to Connect to the station (Callsign) chosen above:

CONNECT (Callsign) <Enter>

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After pressing <Enter>, you should observe the TX LCD light. Your monitor should soon display:

*** CONNECTED to (Callsign)

If you see this, you have just Connected to your first packet station. Identify what type of station you have connected to, and respond appropriately. After you have connected to a few stations, you should skip to section 4.4 to learn more about the PK-900 packet features.

4.3.6 I'm Having Trouble Connecting

If the station you are trying to connect to is connected to someone else, you may see the following message:

*** BUSY from (Callsign) DISCONNECTED

If you see this, simply wait a few minutes and try again or try connecting to a different station from your MHEARD list.

If the distant station cannot hear you, you may see the following:

*** Retry count exceeded *** DISCONNECTED:

A number of different things can cause this to occur. It may simply be that the station you are trying to connect to is out of your transmitter's range. It is possible however that something more serious is wrong, so you should check the following before proceeding:

o The Loopback Test in section 4.2 functions properly. o Your PK-900's AFSK Output Level control, radio microphone gain, and deviation are set properly as discussed in Section 3.5.1. o All cables and connectors are properly installed. o Your radio's volume and squelch are set for local conditions. o You are following the correct procedure for Connecting. Remember that this procedure is slightly different for AEA PAKRATT programs than it is for terminals or terminal-programs. o The "VHF" command is "ON" for VHF/UHF operation. o HB is set to 1200 o RESET the PK-900 with the RESET command or RESET switch and start over with section 4.2 of this chapter.

If none of the above correct the problem, ask one of your area's experienced packet operators to listen to your transmissions. Both you and your partner should set MONITOR and MCON to 6, and then send some packets. Each station should display packets sent by the other.

o If only one station is "hearing" packets, check the modulator and transmitter of that station and the demodulator and receiver of the other station. o Experiment with the TXDELAY parameter for the sending TNC. Try setting TXDELAY 64 for a long delay. If this solves the problem, decrease TXDELAY to the smallest value that works all the time.

If you still cannot connect to other stations, then you should contact AEA Technical Support as outlined in the PREFACE of this manual.

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4.4 More Packet Features

Now that you have worked a few packet stations, it is time to learn a little more about the other packet capabilities of the PK-900. Rather than explain all the features in detail, we will leave the specifics to the command descriptions in the Command Summary Appendix.

4.4.1 LCD Status and Mode Indicators

Your PK-900 front panel display is divided into four sections as shown below:

PK-900's Front Panel LCD Indicators.

The left two thirds of the LCD display contain information relating to the operation of radio port 1.

The upper right third of the LCD display contains information about the operation of Radio port 2.

The middle of the right third of the LCD display contains system information.

The very bottom of the LCD display is a 20 segment bargraph used for tuning Radio port 1.

Your PK-900's front-panel LCD display shows the Status of each Radio Port at a glance. The following describes the function of each of the LCD annunciators.

NAME DESCRIPTION LCD FUNCTION

RADIO 1 Column Heading On when port 1 enabled RADIO 2 Column Heading On when port 2 enabled

DCD Data Carrier Detect Lit when data signals are received

TX Send Lit when PTT line is active

MODE Column Heading Always on. Indicates operating mode of port 1

MORSE Morse Code Mode Lit when in Morse mode

BAUDOT 5 Level RTTY Mode Lit when in Baudot mode

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NAME DESCRIPTION LCD FUNCTION

ASCII 7 Level RTTY Mode Lit when in ASCII mode

FAX Facsimile Mode Lit when in Facsimile

SSTV Slow Scan TV Mode Lit when in SSTV mode

SIAM Signal Identification Lit when in SIAM mode Mode

TDM Time Division Multiplex Lit when in TDM mode Mode

EXP Used for testing Lit when test inpt high

PACKET Packet Mode Lit when in packet

DISCONNECTED Packet status Lit when not connected

DISCONNECT Packet status Lit when disconnecting

CONNECT Packet status Lit when connecting

CONNECTED Packet status Lit when connected

UNACKNOWLEDGED Packet status Lit when you have sent a packet that has not yet been acknowledged

ACKNOWLEDGED Packet status Lit when all your packets have been acknowledged.

TOR AMTOR Mode Lit when TOR mode

FEC AMTOR or PACTOR Mode Lit when in FEC mode

ARQ AMTOR or PACTOR Mode Lit when in ARQ mode

ARQ L ARQ Listen mode Lit when in ARQ L mode

SEL-FEC AMTOR Selective Calling ModeLit when is SEL-FEC

NAVTEX NAVTEX Mode Lit when in NAVTEX

PACTOR PACTOR Mode Lit when in PACTOR

IDLE TOR Status Lit when no data is received from an active channel

REQUEST TOR Status Lit when data receiving station requests repeat.

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NAME DESCRIPTION LCD FUNCTION

PHASE TOR Status Indicates synchroniza tion of the ARQ calling ARQ listen signal

OVER TOR Status Indicates changeover of data transmission direction

TRAFFIC TOR Status Indicates data reception or transmission.

ERROR TOR Status Indicates reception of erroneous data

STANDBY TOR Status Lit when not receiving transmitting

COMPRESS TOR Status Lit when sending or receiving compressed data

SYSTEM Column Heading Always on.

HOST System status Indicates system is in host mode. Used for PCPackratt program

MULT System Status Lit when multiple con nections exist Blinks when receive buffer is full

TRANSPARENT System Status Indicates transparent mode.

COMMAND System Status Indicates the PK-900 is able to accept commands

CONVERSE System Status Lit when the PK-900 is ready to send data

MAIL Mailbox Status Lit when mailbox contains information

MARK Bargraph Indicates mark end of tuning indicator

SPACE Bargraph Indicates space end of tuning indicator

4.4.2 Automatic Greetings

You can tell your PK-900 to send an automatic greeting (CTEXT) to any station that connects to you. This can be used to tell others

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that you are out of the shack and to leave you a message or for any other message you would like to send.

To enable the CTEXT message, set your Connect Text message using the CTEXT command. Then set CMSG ON to enable the Connect Message feature. Think of the CTEXT message as the message your telephone answering machine might give to a caller.

4.4.3 Beacon Operation

Your PK-900 can send an automatic "beacon" message at a specified time interval. A beacon can send special announcements, or let others know you are on the air. To enable beacon operation do the following:

o Set your beacon message with the BTEXT command. o Set the beacon interval using the BEACON EVERY or AFTER command. o A beacon frame is sent to the path given in the UNPROTO command.

In the early days of packet, the beacon was useful to show your presence on the packet channel. With the growth of packet, many users feel that beacons have outlived their usefulness and interfere with traffic. Use your beacon with consideration for others.

As a reminder, if you set the BEACON timing at a value considered too small for busy channels (less than "90"), you'll see:

WARNING: BEACON too often

4.4.4 Digipeater Details

You may wish to connect to a packet station that is beyond your direct radio range. If a third packet station is on the air and both you and the station you want to talk to are in range of that third station, the third station can relay or "digipeat" your packets. You simply set the "digipeater" routing when you connect. Here's a sketch that shows how digipeating can solve problems:

WX2BBB / \ WX1AAA _______/ \_________ WX3CCC

You are station WX1AAA - you want to have a packet QSO with WX3CCC. There is a mountain between you and WX3CCC; you're out of simplex range of each other. However, you know that there's a packet station located on the ridge - WX2BBB - which is in range of you and WX3CCC.

Instruct your PK-900 to set up a connection to WX3CCC using WX2BBB as an intermediate digipeater. When you initiate the Connect, type: "CONNECT WX3CCC VIA WX2BBB".

If WX2BBB has turned off his station, you can still contact WX3CCC by going around the ridge through WX2DDD and WX2EEE as shown:

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xxxx / \ WX1AAA _________/ \__________ WX3CCC . . . .

WX2DDD . . . . . . . . WX2EEE

This time, type the connect command like this:

CONNECT WX3CCC VIA WX2DDD,WX2EEE

Type the digipeaters' call signs in the exact order of the intended path from your station to the station with which you wish to connect. You can specify a routing list of up to eight intermediate stations.

In practice this does not work very well, and Networking Switches such as NET/ROM have replaced digipeating for the most part. Still, it is sometimes necessary to digipeat through one or two stations.

4.4.4.1 Are You a Digipeater?

Your packet station can be a digipeater for other stations. You don't have to "do" anything - your PK-900 will digipeat other stations - unless you tell it not to! with the DFROM command.

If your transmitter is keyed when you're not using it, or during lulls in your own conversations, you're being used as a digipeater by some other stations. This won't bother your chat with your partner.

If you wish to monitor the other stations that are using you as a digipeater then set the command MDIGI ON.

4.4.5 Monitoring Other Stations

Use the MONITOR command to determine what kinds of packets you will see when you are NOT connected to another station. "MONITOR" takes a numerical value between "0" and "6." Each higher number adds more detail to your monitoring. The meanings of the MONITOR numbers are:

0 Monitoring is disabled.

1 Only unnumbered, "unconnected" frames are displayed. This setting will display Beacons, but not display connected stations.

2 Numbered (I) frames are also displayed. Use this setting to monitor connected conversations in progress on the channel.

3 Connect request ("C") frames and disconnect ("D") request packets in addition to the above are displayed.

4 This is your PK-900's default value. Unnumbered acknowledgment (UA) of connect and disconnect frames are also displayed.

5 Receiver Ready (RR), Receiver Not Ready (RN), Reject (RJ), and Frame Reject (FR) supervisory frames are also displayed.

6 Poll/Final bit and sequence numbers of monitored frames are shown.

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Understanding all types of packet frames is not necessary to operate packet. Packet operators should however understand that there are many types of control frames that do not contain printable data.

Your PK-900 can display these frames, but most users only want to see frames with information. For this reason, the MONITOR command default (4) does not display all the packets that the PK-900 hears.

NOTE: If you will be leaving your PK-900 on to accept connects from others while your computer is off, set MONITOR to 0 (zero) and type a <CTRL-S> to hold the data. If you are using an AEA program, you must set the MONITOR command to 0, but our programs automatically perform the <CTRL-S> function for you. If this is not done, the PK-900 memory will be filled with useless data and prevent others from connecting with you.

4.4.5.1 Monitoring the Packet Networking Switches

There are other types of AX.25 frames used by networking switches that the PK-900 does not normally display. These other frames can be seen by turning the MPROTO command ON. Some of the packets monitored with MPROTO ON will contain information that may interfere with the screen on your terminal or computer causing it to look "funny". For this reason the MPROTO command default is OFF.

If you are hearing packets that sound strong but are not displayed, setting MONITOR to 6 and MPROTO ON should show them. If you are curious about the packets that do not print, you may find the command WHYNOT useful. When WHYNOT is turned ON, the PK-900 will give a reason why each packet was not displayed. If you are interested in exactly how the packets are represented, turn on the TRACE command. See the Command Summary for more information about WHYNOT and TRACE.

4.4.5.2 Monitoring Other Stations While Connected

When you are NOT connected to another station, the MONITOR command discussed above determines what packets are displayed. When you ARE connected, the MCON command determines what packets are shown.

The default of MCON is 0 which tells the PK-900 NOT to monitor any packets while you are connected. Most users like this so they are not disturbed with monitored channel data when they are communicating with another station. If it is desired to monitor channel activity while you are connected, then remember to set MCON to an appropriate Monitor number from the list in 4.4.5 or the in command summary.

4.4.5.3 Selective Monitoring

After you have monitored channel activity for a while, you may decide there are only a few stations you wish to display. The PK-900 will let you do this with the Monitor-TO (MTO) and Monitor-FROM (MFROM) commands. With the MBELL command, you can even be alerted when a certain station transmits on the frequency. These commands work in conjunction with MONITOR and MCON commands.

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4.4.5.4 The MFILTER Command

Some terminals and computer programs are sensitive to certain characters that may appear in monitored packets. You will know this is happening if occasionally the cursor on your screen moves to strange places causing the copy to be garbled.

The PK-900 default for MFILTER is $80 which prevents most control characters from interfering with your display. If you find a terminal or printer is bothered by certain characters, see the Command Summary for more information on the MFILTER command.

4.4.5.5 Monitor Without Callsign Headers

Sometimes you may wish to monitor certain stations without wanting to look at the packet callsign headers. This can be useful when monitoring message traffic from a large Packet Bulletin Board System (PBBS). The MBX command allows you to choose the callsign of a station, or a pair of stations you wish to monitor without seeing the packet headers. See the Command Summary for details.

4.4.5.6 MSTAMP, The Monitor Time-Stamp Command

Monitored packets can be time-stamped if the real-time clock has been set with the DAYTIME command. To timestamp monitored packets, turn the MSTAMP command ON. Turning the DAYSTAMP command ON adds the date to the timestamp provided by the MSTAMP command.

4.4.6 Packet Connects

When you turn your PK-900 on and enter your callsign, anyone can Connect to you. If you are at your terminal or computer when this occurs you will see the LCD for the appropriate channel showing the word CONNECTED.

When a packet connection occurs, the PK-900 automatically switches to the Converse mode so what you type on the keyboard will be sent to the connected station. The NEWMODE and NOMODE commands control when and how the PK-900 changes to and from Command mode in response to packet connects and disconnects. You will probably never need to change these settings.

4.4.6.1 Time-Stamping Connects

Sometimes it is useful to know what time someone connected to you - perhaps for logging. To time-stamp your connects and disconnects turn the command CONSTAMP ON. As discussed in the Monitoring section above, turning the command DAYSTAMP ON adds the date to this as well. The DAYTIME command must first be set for this to operate.

4.4.6.2 Connect Alarm

If you busy doing other things, you may want to be alerted when someone connects to you. Turning the command CBELL ON rings the bell on your terminal when a station connects to, or disconnects from you.

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4.4.7 Packet Formatting and Editing

Some of your PK-900's command parameters affect how your packets are formatted - how your typing appears to the rest of the world. Other commands let you correct typing errors before your packet is sent, cancel lines or cancel packets if necessary.

4.4.7.1 Carriage Returns and Linefeeds in Packets

Most people use packet radio for sending and receiving messages or conversing with other Amateurs. The character used to send a packet is defined with the command SENDPAC which defaults to a Carriage Return ($0D). The SENDPAC character may be changed, but most will find the Carriage Return or Enter key to be a natural choice. Similarly, your PK-900 will include a Carriage Return in the packet you send to other stations since this makes for a more natural conversation. The ACRPACK command (default ON) controls this feature, but most people never want to change this.

The PK-900 also has the capability of adding a linefeed character ($0A) automatically to packets that you send to others. If you encounter a station that says your packets are overprinting, you may want to turn the ALFPACK or the ILFPACK command ON temporarily.

4.4.7.2 Canceling Lines and Packets

Most of the time, the Backspace key (or the Delete key on some computers) is all that is needed to edit a line before it is sent. Occasionally it may be helpful to cancel the line, or the entire packet you are entering with one key stroke. The CANLINE character (default <CTRL-X>) will cancel the entire line you are typing. The CANPAC character (default <CTRL-Y>) will delete the entire packet you are entering. These commands can be helpful, but use them with care.

4.4.7.3 Redisplay

If you have erased and retyped many characters, you may want to see the sentence you are currently entering "redisplayed" by the PK-900, especially if BKONDEL is OFF. Your PK-900 will show the line you're entering when you type the REDISPLAY character (default <CTRL-R>). This will also allow you to display any packets you might have received while you were typing.

4.4.7.4 The PASS Character

If you are using a terminal or terminal program, the following may be useful. Sometimes you may want to include a special input character such as a Carriage Return (the SENDPAC character) in a packet. For example, to send several lines in the same packet, you must include <CR> at the end of each line. You can include any character in a packet (including all special characters) by prefixing that character with the PASS character (default <CTRL-V>):

I wasn't at the meeting.<CTRL-V><CR> What happened?

Without the PASS character, this message would go out as two packets.

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By prefixing the first <CR> with <CTRL-V>, you send it all at once, while maintaining the <CR> as part of the text. The PASS character can be useful in formatting text Messages such as CTEXT as well.

4.4.8 Packet Transmit Timing

Your PK-900 has a number of built-in timers used to control the packet protocol and transmit timing. The default values have been set at the factory to provide reasonable performance, but the values may not be optimum for your local area. Most protocol parameters should be adjusted only after carefully reading about them later in the chapter. You SHOULD however adjust TXDELAY for your transmitter as indicated below.

4.4.8.1 TXDELAY and AUDELAY

Radios vary in the time it takes to switch from receive to transmit. If your PK-900 starts sending data before your transmitter is up to power, the packet will not be received properly at the distant end.

TXDELAY controls the delay between your transmitter's key-up and the moment when your PK-900 starts sending data. The default value of 30 corresponds to a time of 300 ms and works with most VHF/UHF FM transceivers. With modern transceivers TXDELAY can often be reduced which will improve packet performance in your area. You should perform the following procedure to optimize TXDELAY for your radio.

o Find another station who can reliably digipeat your signals.

o Set your UNPROTO path to TEST via the callsign of the station who can digipeat your signals. Example: UNPROTO TEST VIA WX2ABC

o Set the MONITOR command to at least 1.

o Go to CONVERSE mode and send a few packets by pressing the <Enter> key. Note that you should see them on your own screen when they are digipeated by the other station.

o Start reducing TXDELAY by units of 5 each time making sure the other station is still digipeating ALL your UNPROTO packets. Eventually you will find a value where the other station can no longer copy your packets to digipeat them.

o When this happens, increase TXDELAY in units of one or two until the other station again digipeats ALL of your packets. This will be the optimum setting of TXDELAY.

After TXDELAY is adjusted as indicated above you may want to adjust the audio delay (AUDELAY) as indicated in the Command Summary.

The next sections of this chapter will discuss some of the more advanced packet features including Multiple Connects, Packet Timing and Protocol, and HF Packet Operation.

4.4.8.2 AXDELAY and AXHANG

Although it is not common, packet can be used through voice repeaters.

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When sending packets through an audio repeater you may require a longer key-up delay than is normally needed for direct communications. The AXDELAY command adds more key-up delay in your PK-900 so that the repeater can stabilize. The AXHANG command sets the time your PK-900 assumes is needed for the repeater to drop.

4.5 Packet Protocol Basics

Here we will talk a little about the AX.25 packet protocol. You do not need to know the protocol to use packet, but it helps in understanding the protocol parameters.

There are two modes of packet transmissions, Connected mode and Unconnected mode. Usually you will converse with another packet station in Connected mode. Still, the Unconnected or Unprotocol mode comes in handy for beacon transmissions and roundtable conversations.

All packets have basically the same construction. Packets contain source and destination callsigns (and any digipeaters if used), as well as information identifying the type of packet. This packet identification can be seen with the MONITOR command discussed earlier. All packets contain an error check code called the CRC. This virtually ensures that when a packet is received, it will not con tain a single error. The command PASSALL can disable the CRC error check, but this should only be done for experimental purposes.

4.5.1 Unconnected Packets

In order to allow amateurs to send message beacons and to call CQ, the AX.25 protocol has the ability to send packets that are intended for more than one specific packet station to see. Since all packets must have a destination "callsign", the PK-900 sends Unprotocol packets TO the callsign of CQ. This can be changed with the UNPROTO command, but most people like this since it makes calling CQ easy.

4.5.2 Connected Packets

When you Connect to another station, the AX.25 packet protocol ensures that the station to whom you are connected receives all the packets that you send. Similarly, the protocol ensures you will receive all the packets that the other station sends to you. The following describes briefly how the protocol does this.

4.5.3 FRACK and RETRY

When the PK-900 sends a packet to a Connected station, it expects an acknowledgment (ACK) packet from the other station to confirm that the packet was received. The AX.25 packet protocol will automatically retransmit (Retry) packets when an acknowledgment is not received from the distant end of the link within a specified time.

The FRACK command (FRame ACKnowledge time) sets the time lapse allowed before the originating station retransmits (retries) the packet.

The RETRY command sets the maximum number of retransmissions before the sending station terminates the connection (DISCONNECTS).

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The TRIES counter keeps track of the retries that have occurred on the current packet.

4.5.4 PACLEN and MAXFRAME

Packets will be sent either when the <Enter> key is pressed or when the maximum packet size is exceeded. The maximum packet size is set by the PACLEN command which defaults to 128 characters. When large amounts of data need to be sent, this value can be increased to 256. When conditions are poor or the channel is crowded as on HF packet, this value should be reduced to 64 or less.

The packet protocol allows more than one frame to be sent in a single transmission. The default is set to 4 by the MAXFRAME command. When conditions are good up to 7 frames can be sent to speed data transfer. When conditions are poor or the channel is crowded, MAXFRAME should be reduced to only 1 frame.

4.5.5 Reducing Errors through Collision Avoidance

If every packet station could hear every other station, there would be very few "collisions" due to stations transmitting at the same time. Since packet operates over radio, there are often many stations on the same frequency that cannot hear each other. Digipeaters and network nodes allow these stations to communicate with each other, but this increases the chances of collisions.

The first attempt to avoid collisions was through the use of the DWAIT and RESPTIME timers. DWAIT forced the TNC to delay the transmission of any packet except for digipeated frames by the time selected. This fixed timer helped, but packet was still plagued by collisions. The RESPTIME was added to help with large file transfers. Still, more needed to be done to reduce collisions.

Another attempt to reduce collisions was the introduction of AX.25 version 2 protocol. On VHF packet, most everyone uses version 2 which is controlled by the AX25L2V2 command (default ON). On VHF this helps, but some users on HF packet are turning this command OFF.

An exponentially distributed random wait method was proposed by Phil Karn (KA9Q) called P-persistent CSMA. When the command PPERSIST is ON (default) the PK-900 uses the number set in PERSIST and the time value set by the SLOTTIME command to more randomly distribute the transmit wait time. This is more efficient than using the DWAIT time.

As a further attempt to improve packet performance, Eric Gustafson (N7CL) proposed giving priority to acknowledgment packets (ACKs). This protocol is controlled by the ACKPRIOR command which currently defaults OFF. Check with experienced packet users in your area and find out if they are using priority acknowledge or have changed any other packet parameters.

4.5.6 CHECK and RELINK

If someone connects to you and then turns his TNC off, you would probably not want to stay connected to the station forever. The CHECK timer determines the amount of time the PK-900 will wait before

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testing the link if no data has been sent or received.

The RELINK command sets what happens when the CHECK timer expires. If RELINK is OFF, the PK-900 changes to the Disconnected state. If ON, the PK-900 attempts to reconnect to the other station.

4.6 Multiple Connection Operation

Since packet radio allows many stations to share the same channel, many QSOs can be going on at the same time. Because packet has this channel sharing capability, there is no reason you cannot connect to more than one station at the same time. Being connected to multiple stations at once is a powerful feature of your PK-900.

4.6.1 Multiple Connection Description

The PK-900 offers 10 logical packet channels on Radio Port 1 and 26 logical packet channels when using Radio Port 2. Each logical channel can support a connection with another packet station. So with the PK-900, you may be connected to a total of 36 other packet stations simultaneously.

Multiple connect operation is much like a multi-line telephone with automatic hold. When you are connected to multiple stations you will automatically receive everything sent TO you. You must select the proper channel (in effect push the proper line button on the telephone) to send data to a particular station.

If you are using an AEA PAKRATT program, this is described in the program manual. If you are using a terminal, the rest of this section will describe how to set up the PK-900 for multiple connections.

4.6.2 The Channel Switching Character

The logical channels are selected with the CHSWITCH character. You must choose a CHSWITCH character that you do not normally type such as the vertical bar "|" (ASCII $7C), or the tilde "~" (ASCII $7E). Once this has been selected and entered into the PK-900, you may initiate multiple connections with others on your radio channel.

The ten logical channels on Radio Port 1 are numbered 0-9. The 26 logical channels on Radio Port 2 are labeled A-Z. After the CHSWITCH character has been selected, you can now initiate connects on any of the logical channels numbered zero through nine (0-9) on Port 1 or "A" through "Z" on Port 2.

To change logical channels on Radio Port 1, press the CHSWITCH character you just defined, and then a number from 0-9. Remember that the text that you type will only be sent out to the station connected to the logical channel your PK-900 is currently on.

This same procedure is used to select a logical channel on Radio Port 2, only instead of pressing a channel "number" from 0-9, a "letter" from A-Z is pressed. This is in fact the method used to switch back and forth between Radio Ports 1 and 2. Please see the

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section on switching between Radio Ports later in this chapter for a more complete description of this process.

4.6.3 Will You Accept Multiple Connects

Setting the CHSWITCH character only allows you to make outgoing multiple connects. For the PK-900 to allow multiple incoming connections, you must set the USERS parameter to more than one (1) for each Port that you wish to allow incoming multiple connections. The number you enter in the USERS command tells the PK-900 how many other users you will allow to connect to you at one time. If more than this number try to connect, they will get the "busy" response.

4.6.4 Display Multiple Connected Callsigns

Multiple Connection operation can be confusing - especially remembering who is connected on what channel. To help this, you may want to turn ON the CHCALL command to display the callsign of the station who is connected to you on a given channel.

4.6.5 Doubling Received CHSWITCH Characters

If you want to be able to tell the difference between the CHSWITCH characters you type, and characters from other stations that happen to be the same as your CHSWITCH character, then set CHDOUBLE ON.

4.6.6 Checking Your Connect Status with the CSTATUS Command

To check what channels your PK-900 is currently set to, as well as who is connected to you, you may find the CSTATUS command helpful. CSTATUS is an immediate command that shows you the status of all packet channels as well as the channel you are currently on.

4.6.7 The MULT LCD

You will know you are connected to more than one packet station on each Radio Port when the MULT LCD the PK-900 lights.

NOTE: The MULT LCD will blink if the PK-900's receive buffer is filled. This can happen if your computer is not connected to the PK-900 and the MONITOR command was left ON, or if for some reason, your communications program no longer can accept any further inbound data.

4.7 HF Packet Operation

HF Packet is much trickier than operating on VHF. In this section we will assume you have as completed section 4.2 of this chapter and at least read section 4.3 and the MONITORING sections of 4.4. If at all possible, get some experience with VHF packet before trying packet on HF. Although this is not absolutely required, the experience will help you make HF packet contacts.

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4.7.1 Where to Operate HF Packet

Before you can operate HF Packet, you must first find the activity. Most HF packet operation is on the 20-meter amateur band starting at

14.103 MHz and every 2 kHz above that up to 14.111 MHz. Note that

14.103 MHz is the HF Packet calling frequency and a good place to start. The higher frequencies such as 14.109 and 14.111 are used mostly by HF PBBS systems and are not good places to look for a QSO.

4.7.2 PK-900 HF Packet Settings

Radio Port 1 on the PK-900 is intended for multi-mode operation so either a VHF or HF transceiver may be connected. The packet parameter defaults have been set for VHF Packet operation on both radio ports and should be changed for HF packet operation as shown in the table below.

The table below shows the parameters that should be set differently for HF and VHF packet operation. If you will be operating HF Packet, you should make note of these parameters and change them accordingly.

Recommended Port 1 & 2 Defaults 300 baud HF Packet 1200 baud VHF Packet SLOTTIME 12 SLOTTIME 30 PACLEN 64 or less PACLEN 128 MAXFRAME 1 MAXFRAME 4 FRACK 8 FRACK 5 VHF OFF VHF ON HBAUD 300 HBAUD 1200 MODEM 10 MODEM 11/4

Note that the HF (VHF OFF) modem number is tied to the QHPACKET command and the VHF (VHF ON) modem number is tied to QVPACKET. The Radio Port baud rate is not changed when you change modems. You select the appropriate baud rate with the HBaud command.

You should set MONITOR to 6 on the port used for HF Packet when tuning in your first HF Packet stations.

4.7.3 HF Receiver Settings

Set your HF receiver (or transceiver) to Lower Sideband (LSB) unless you connected your PK-900 through the direct FSK keying lines, in which case you should select the FSK or RTTY operating mode. Adjust the volume to a comfortable listening level.

4.7.4 Tuning in HF Packet Stations

Perhaps the most difficult thing about HF Packet operation is making sure the station is tuned properly and stays tuned. Since HF packet uses 200 Hz Frequency Shift Keying to send data (2110/2310 Hz), tuning accuracy is very important. Being off frequency by only 20 Hz can make a noticeable difference in the PK-900's ability to copy packet stations. Your have a choice of three types of tuning indi cator types. Use the BARgraph command to change the indicator type.

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Follow the tuning procedure below carefully for the best results in tuning in HF packet stations.

o Make certain your HF receiver is either in LSB or FSK depending on your PK-900 set-up.

o Turn any IF-Shift and Passband-Tuning controls to the Center or OFF position.

o Tune your receiver to 14.103 MHz (or another frequency where you know there is HF packet activity) and listen to the packets.

o Slowly vary the tuning knob on your receiver and look for a display on the PK-900 tuning indicator like the one below.

—————————————————————————————————————————————————————————————— MARK |       | SPACE —————————————————————————————————————————————————————————————— Tuning correct for discriminator indicator (BAR 0)

—————————————————————————————————————————————————————————————— |                 | —————————————————————————————————————————————————————————————— Tuning correct for magic eye indicator (BAR 3)

—————————————————————————————————————————————————————————————— |   | —————————————————————————————————————————————————————————————— Tuning correct for center tune indicator (BAR 2)

If the tuning indicator looks like the one below, the audio frequency from your speaker is too low for the PK-900 to copy packets. Slowly tune the VFO and make the frequency higher.

—————————————————————————————————————————————————————————————— MARK |        | SPACE —————————————————————————————————————————————————————————————— Tuning too low for discriminator indicator (BAR 0)

—————————————————————————————————————————————————————————————— |          | —————————————————————————————————————————————————————————————— Tuning too low for magic eye indicator (BAR 3)

—————————————————————————————————————————————————————————————— |   | —————————————————————————————————————————————————————————————— Tuning too low for center tune indicator (BAR 2)

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If the tuning indicator looks like the one below, the audio frequency from your speaker is too high for the PK-900 to copy packets. Slowly tune the VFO and make the frequency lower.

—————————————————————————————————————————————————————————————— MARK |         | SPACE —————————————————————————————————————————————————————————————— Tuning too high for discriminator indicator (BAR 0)

—————————————————————————————————————————————————————————————— |           | —————————————————————————————————————————————————————————————— Tuning too high for magic eye indicator (BAR 3)

—————————————————————————————————————————————————————————————— |   | —————————————————————————————————————————————————————————————— Tuning too high for center tune indicator (BAR 2)

o Adjust the volume on the receiver so that the DCD LCD lights when a properly tuned packet is being received. You must also make certain that the DCD LCD goes out when no packet signals are present on the frequency.

After you have a packet station tuned in, you should start seeing HF packet stations on your display.

4.7.5 Transmitter Adjustments

Make sure your PK-900 is adjusted for your SSB transmitter as described in section 3.5 and 3.5.2 of this manual before transmitting. These are very critical adjustments. If the AFSK level and transmitter microphone gain are not adjusted properly, other stations will not be able to copy your packets. Check your plate or collector current or the power output of your rig before going on the air.

4.7.6 Going On The Air

Make sure your transmitter and antenna are tuned and adjusted for the band and operating frequency you are using.

On HF there are two ways you can go about talking to another station.

o First, you can look at the packets you have just MONITORED (or in your MHEARD list) and choose one of them to connect to.

o You can also "Call CQ" by entering the CONVERSE mode and pressing the <Enter> key a few times.

Either way you decide to go on the air, remember that things happen much more slowly on HF packet than they do on VHF packet. HF packet requires patience and careful tuning in order to be used successfully.

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If you are having problems connecting to other HF packet stations, try working with an experienced HF packet operator in your area and listen to each other's signals. See if you can copy each other's packet signals. If he cannot copy your signals, have him listen to your signal in the CALIBRATE mode to make sure you are transmitting a pure tone. As mentioned earlier, any distortion caused by overmodulation or RF feedback will make your signal difficult or impossible to copy.

4.8 Controlling the Radio Ports

If you are using an AEA PAKRATT program designed for the PK-900, switching between Radio Ports is described in the program manual. If you are using a computer terminal, terminal program or the "Dumb Terminal Mode" of an older PAKRATT program, this section will describe how to control and switch between the radio ports. The RADIO command allows either (or both) Radio Port(s) to be disabled. Before the second radio port can be used for packet operation, the proper modem must be selected using the 2MODem command.

Radio Port 2 Modems

1: Internal 200: 1070/1270 2: Internal 200: 2025/2225 3: Internal 1000: 1200/2200 4: Internal 1000: 1200/2200 eq. 5: Internal 200: 1180/980 6: Internal 200: 1850/1650 7: Internal 800: 2100/1300 8: Internal 800: 2100/1300 eq. 9: Internal option 10: Modem disconnect header

4.8.1 Selecting Modems

The various modems available in the PK-900 can be seen with the DIRECT(ory) command. To display all the available modems simply enter the Command Mode of the PK-900 and then type DIR as shown.

DIR <Enter>

The PK-900 will respond with the following:

- Port 1 - - Port 2 1: FSK 45 bps 170: 2125/2295 1: Internal 200: 1070/1270 2: FSK 100 bps 170: 2125/2295 2: Internal 200: 2025/2225 3: FSK 45 bps 200: 2110/2310 3: Internal 1000: 1200/2200 4: FSK 100 bps 200: 2110/2310 4: Internal 1000: 1200/2200 eq. 5: FSK 100 bps 425: 2125/2550 5: Internal 200: 1180/980 6: FSK 100 bps 850: 2125/2975 6: Internal 200: 1850/1650 7: FSK 100 bps 850: 1275/2125 7: Internal 800: 2100/1300 8: Analog 900/2500 8: Internal 800: 2100/1300 eq. 9: FSK 2400 bps 800: 1300/2100 9: Internal option 10: FSK 300 bps 200: 2110/2310 10: Modem disconnect header 11: FSK 1200 bps 1000: 1200/2200 12: Morse 750

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Any modem from this list may be selected with the command MODEM. For example, let's say that you want to operate 300 bps HF packet on radio port 1 and 1200 bps VHF packet on radio port 2. This operation is achieved with radio port 1 modem 10 and radio port 2 modem 4. To load these modems, first enter the Command Mode of the PK-900 and then type MODEM 10/4 as shown below:

MODEM 10/4 <Enter>

The PK-900 will respond with the following:

MODem was x/x (whatever modems were in use) MODem now 10/4 cmd:*** HBaud now 300/1200

Either modem may be selected individually. To change only radio port one's modem, for example, type MODEM 10 <Enter>. To change only radio port two's modem, you would type MODEM /4 <Enter>.

4.8.2 Displaying Received Data

When radio port 2 is active in the PK-900, received data is displayed from both Radio Ports at the same time. This allows you to operate on HF and not miss any local Packet connects or information from VHF DX spotting nets.

The PK-900 displays monitored packets by prefacing each packet with a port designator "p1" for radio port 1 and "p2" for radio port 2. For instance, let's say that modems 10/4 are selected and you are monitoring HF packet activity on Radio Port 1, and VHF packet activity on Radio Port 2. You might see something like the following:

p1 WX1AAA*>CQ [UI]: { WX1AAA calling CQ on Radio Port 1 (HF) } p1 WX1AAA*>CQ [UI]:

p2 WY7DDD*>WY7EEE [I,P;1,1]: { An Information Frame from Hello Bob, how are you? WY7DDD to WY7EEE monitored on Radio Port 2 (VHF) }

p2 WY7EEE*>WY7DDD (RR,F;1) { Acknowledgment of the above I-Frame on Radio Port 2 }

p1 WX2BBB*>WX1AAA [C,P] { WX2BBB attempting to connect to WX1AAA on Radio Port 1 }

p1 WX1AAA*>WX2BBB (UA,F) { WX1AAA acknowledging the connect request }

p1 WX2BBB*>WX1AAA [I,P;0,0]: { An Information Frame from Hello Bob, how are you? WX2BBB to WX1AAA monitored on Radio Port 1 (HF) }

The first packet shown above is an Unprotocol "CQ" packet from WX1AAA that was received on Radio Port 1. We know this was received on Port 1 because of the "p1" shown in front of the packet. (Remember from

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the section on Multi-connect packet operation that Packets received on Radio port 1 will be on one of the ten logical channels numbered 0-9.) The second packet is another "CQ" from WX1AAA. Again, there is a "p1" in front of it so we know it was also received on Radio Port 1.

The third packet is an Information-Frame, or simply an "I-Frame" that was monitored on Radio Port 2. We know this was received on Radio Port 2 because of the "p2" shown before the packet. Remember that Packets received on Radio port 2 will be on one of the 26 logical channels designated A-Z.

The fourth packet is an acknowledgment to the previous I-Frame received on Radio Port 2. Again, the "p2" in front of the packet tells us it was received on Radio Port 2.

The fifth packet is a Connect Request from WX2BBB to WX1AAA that was monitored on Radio Port 1. The "p1" in front tells us so. The sixth packet is an acknowledgment by WX1AAA to the connect request. The seventh and last packet shown above, is the first I-Frame that WX2BBB is sending to WX1AAA after they have connected.

4.8.3 Controlling Your Transmitted Text

If you are using an AEA PAKRATT program designed for the PK-900, switching between Radio Ports is described in the program manual. If you are using a computer terminal, terminal program or the "Dumb Terminal Mode" of an older PAKRATT program, this section will describe how to control and switch between the radio ports.

4.8.3.1 Defining the Channel Switching Character CHSWITCH

Before you can switch between logical channels or Radio Ports you must define a Channel Switching character that you will use to signal the PK-900 that you want to redirect your transmitted text. This special character is defined with the CHSWITCH command and should be one that you do not normally type in conversational text such as the vertical bar "|" ($7C), or the tilde "~" ($7E). To enter the vertical bar "|" as the CHSWITCH character, first enter the Command Mode of the PK-900 and then type CHSWITCH $7C as shown below:

CHSWITCH $7C <Enter>

The PK-900 will respond with the following:

CHSWitch was $00 CHSWitch now $7C (|)

Once a CHSWITCH character has been entered, you may switch Radio Ports or Packet logical channels of the PK-900 at will.

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4.8.3.2 Switching Between Radio Ports

The ten logical channels on Radio Port 1 are labeled 0-9. The 26 logical channels on Radio Port 2 are labeled A-Z. To select Radio Port 1, press the CHSWITCH character you just defined, followed by a number from 0-9. To select Radio Port 2, press the CHSWITCH character, followed by a letter from A-Z.

After you change Radio Ports or logical channels, the text you type in the CONVERSE mode will be sent to the port and channel selected. If you are connected to another packet station, the text you type will be sent to him or her. If the channel is not connected, the text will be sent in the Unprotocol or unconnected mode.

For example, let's say that you are operating HF Packet on Radio Port 1 and are also available for connects on the local VHF Packet channel on port 2. You connect to an HF packet station and are in the middle

of a QSO when a station on VHF connects to you. The following shows how your screen would look and suggests how you might handle such an occurrence. The underlined text is the text that you have typed.

p1 WX1AAA*>CQ [UI]: { WX1AAA calling CQ on Radio Port 1 (HF) } p1 WX1AAA*>CQ [UI]:

cmd:C WX1AAA { You attempt to connect to station WX1AAA on HF }

*** CONNECTED to WX1AAA { You're connected to WX1AAA }

Hello, name here is Bob. { You send him your name }

Hi Bob, name here is Jim and the { The other station responds QTH is Boston Mass. with his name and location }

A:*** CONNECTED to WX7EEE { WX7EEE connects to you on VHF (Radio Port 2) }

Nice to meet you Jim, QTH here is { You send another packet Seattle, WA. You have a nice signal. to Jim on HF }

Hey Bob, I'm going to the hamfest { Your friend on VHF packet this weekend if you want a ride. wants to go to the hamfest }

|AHello Mike, I am on HF right { You switch ports by typing now talking to a station in Boston. |A and respond on VHF }

0:Thanks Bob, your signal is S-7 { Jim on HF gives you a signal here. I am running 100 Watts into a report. The "0:" shows you tri-bander at 50 ft. this was from Port 1 (HF) }

|0Thanks for the report Jim, you're { You switch back to HF with S-8 and the antenna here is a quad. the |0 and respond to Jim }

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|AYes, I was planning to go Saturday. { You switch to Port 2 with What time do you want to leave? |A to say you want to go }

A:I'll pick you up at 8:00 Bob. { Your friend on VHF responds I'm looking forward to it. to you }

0:Well, it's getting late here and { Jim on HF tells you he has time to pull the plug Bob. shut down for the night }

Sounds good, I'll see you on { You last sent data on Port 2 Saturday morning. and do not need to send |A }

|0Take care Jim, and 73. { You say 73 to Jim on HF }

A:73 Bob. { Your friend on VHF says 73 }

|A<Ctrl-C>A:cmd:D <Enter> { You switch to Port 2 and Disconnect from WX7EEE }

*** DISCONNECTED: WX7EEE { You're now disconnected from WX7EEE on VHF. The A: doesn't show because you last received data on port 2. }

0:*** DISCONNECTED: WX1AAA { WX1AAA disconnects from you on HF (Port 0 }

As you may have noticed, the above technique of communicating on more than one Port at the same time is almost identical to that used for single-port multiconnect packet operation. Let's discuss the sample QSOs above to see how the Port switching occurs.

The first packet frame, we see is a CQ from WX1AAA. This frame is preceded by a "p1" which shows it was received on Radio Port 1.

You have seen WX1AAA calling CQ and decide to connect to him on HF. You simply go to the Command mode (by typing <CTRL-C>) and issue the CONNECT command C WX1AAA as shown on the third line. The fourth line shows that you are now Connected to WX1AAA. Note that you did not have to type "|0" before sending the connect request since the PK-900 defaults to Port 1 until it has been changed to Port 2. If you want to be sure of which channel you want to be on, you could type |0.

Now that you are connected to WX1AAA you greet him and send your name. WX1AAA then gives you his name (Jim) and location which is the way most QSOs begin. Remember in the above example, the underlined text is the text you would have typed.

You have just begun your QSO with WX1AAA when all of a sudden your friend WX7EEE connects to you. WX7EEE has connected on Radio Port 2 (VHF) which is shown by the "A:" before the connect message. Remember that the 26 channel designators for Radio Port 2 are A-Z.

Before you respond to WX7EEE on VHF, you send a packet to Jim on HF giving him your location. After sending this packet, you see WX7EEE on VHF has offered you a ride to the hamfest. We know this packet is from Radio Port 2 since the previous packet displayed by the PK-900

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was the "A:*** CONNECTED" message from Port 2.

Now you want to let WX7EEE on VHF know that you are there, but that you are involved in another QSO on HF. This way he will understand that it may take you a little longer to respond to his packets. Before you can send data to Radio Port 2, you must switch to this Port with "|A" or the text you type will be sent to Radio Port 1.

You receive another packet from Jim on HF giving you a signal report and describing his antenna. Again, the "0:" in front of the text shows this was received on Port 1.

Now you want to give Jim a signal report so you must switch to Port 1 with |0 before your text or it will be sent to WX7EEE on Port 2.

After sending Jim a signal report, you tell your friend on VHF that you want to go to the hamfest with him. You must switch back to Port 2 by typing |A before sending to WX7EEE.

In the next received packet, we see that WX7EEE on VHF agrees to pick you up at 8:00 to go to the hamfest. The "A:" in front of the packet shows that this packet was received on Port 2.

Immediately following, you see a packet from Jim on HF saying it's time to shut down. The "0:" identifies this as a Port 1 packet.

The last packet you sent was to WX7EEE on VHF so you decide to reply to him first. This way you do not have to change Ports. After your reply to WX7EEE, you change to Port 1 with |0 and send your good-byes to Jim on HF.

Your friend WX7EEE on VHF says 73 and signs off with you. After two stations agree to sign off, one of them must initiate a Disconnect. You decide to disconnect from WX7EEE by first switching to Port 2 with |A and then entering Command mode with a <Ctrl-C>. Once you see the Command prompt (cmd:), enter the Disconnect "D" command. Shortly after you do this you see the display "*** DISCONNECTED: WX7EEE" from the PK-900.

Jim on HF has decided to initiate the disconnect with you so the final packet you see is the "0:*** DISCONNECTED: WX1AAA" frame from Port 1.

4.8.3.3 More Thoughts on Port Switching

One problem of having more than one Radio Port is remembering which port you are currently using. In the dual port sample QSOs above, this was not a problem, but after it has been hours or days since you have used your PK-900, you may forget which port you last used.

With AEA Pakratt Software programs, the on-screen status will always show which port you are using so this is not a problem. With other programs, you will have to query the PK-900 with the CSTATUS SHORT command. The CSTATUS command displays the status of the logical channels of Port 1 and Port 2 of the PK-900. The CSTATUS SHORT command displays the status of the active channel and any other connected packet channels. After completing the sample QSOs above, the PK-900 would display the following.

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cmd:CSTATUS S

Ch. A - IO DISCONNECTED

This reminds you that Channel A is your current I/O channel. Any text that you type in the Converse mode will be sent to channel A on Radio Port 2. If you had been connected to any other packet stations, the callsign and channel would have also shown in the display.

Sometimes you might not want to be bothered with anything from the Radio Port you are not using. For these times either Radio Port may be turned OFF with the RADIO command. For example, let's say that in the above example QSO you wanted to work HF packet and did not want to be interrupted with any VHF connects. Typing the following command would cause Radio Port 2 to be disabled.

cmd:RADIO /0 RAdio was 1/2 RAdio now 1/0

When a PK-900 Radio Port is disabled, the front panel LCD Status indicator for that port will be extinguished as a reminder.

4.9 Advanced Packet Operation

Your PK-900 has many commands and features that are not used for day-to-day connects conversations. Still, as you become more familiar with packet, some of these features may become important to you.

4.9.1 Transparent Mode

The TRANSPARENT mode allows any 8-bit binary character to be sent by your packet station. You usually must use the TRANSPARENT mode to transfer binary and program files to and from other stations.

You can enter the TRANSPARENT mode either by typing TRANS at the cmd: prompt after you connect, or by setting CONMODE to TRANS. Either way, once in the transparent mode, any character you type will be sent automatically after the PACTIME setting. This way the PK-900 can send any character. We recommend using HARDWARE flow control in transparent mode but SOFTWARE flow control is available with the TRFLOW and TXFLOW commands. To get back to Command mode after you are finished with transparent mode, you must type the COMMAND character (default <CTRL-C>) 3 times within the "Guard time" set by the CMDTIME command (default 1 second). (Hold down the CTRL key and press C three times rapidly.)

4.9.2 Gateway Operation

The PK-900 can allow packet stations on one radio port to communicate with stations on the other port. When the PK-900 bridges two packet frequencies in this manner, it is said to be a "Gateway." Gateway operation is a dual port feature and requires that the correct port 2 packet modem be loaded. Once this has been done the gateway function is enabled by entering a callsign in MYGATE. The callsign must not be the same call sign and SSID as MYCALL or MYMAIL.

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When another station digipeats via the callsign in MYGATE, your PK-900 will Gateway between Radio Port 1 and Radio Port 2. If you provide this feature to users in your area, you may want to BEACON a message on both ports informing users that your gateway is available.

At this time however, unattended operation below 30 MHz is not legal for US amateurs unless they hold a Special Temporary Authorization (STA) from the FCC. This restriction may someday change, but until then US amateurs must always have control of their HF transmitters when an automatic device such as the PK-900 Gateway is in use.

4.9.3 Sending 8-bit Data in Converse Mode

Sometimes you may need to send a file that contains some 8-bit data, but not need all the features of the TRANSPARENT mode. In this case, you may find turning the command 8BITCONV ON is all that is needed.

4.9.4 The Packet QRA Feature

The PK-900 recognizes UI frames with a destination field of "QRA" and will respond by sending an ID packet. This is helpful for others new to your area that are looking for other packet stations to talk to. To disable this feature and remain anonymous, simply set User BIT 22 OFF (UBIT 22 OFF). The default is ON.

If you wish to see who is available in your local area, simply set your UNPROTO path to QRA and send a packet. Within 1 to 16 seconds other stations should respond to your QRA request by sending an ID packet of their own. This feature is compatible with TAPR's QRA feature introduced in the 1.1.8 firmware release.

4.9.5 The CFROM Command

If you ever want to exclude certain stations from connecting or only allow friends to connect, you may do so with the CFROM Command. See The Command Summary for details of its operation.

4.9.6 Operating in Full-Duplex

Most packet operation is carried on over Half-Duplex transceivers that can transmit and receive but not do both at the same time. When a separate transmitter and receiver is used such as in satellite operation, you may want to use the FULLDUP Command in the PK-900.

4.9.7 Identifying as a Digipeater

If your PK-900 is being used as the primary digipeater in a local area, you may want to enable the HID command. HID will automatically identify your station for others to see.

4.9.8 Digipeater Alias Callsign

If your packet station is being used as the primary digipeater in your local area, you may want to choose a simpler identifier for others to use with the MYALIAS Command.

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4.9.9 Morse ID in Packet

In most countries, packet is an accepted mode of identification so this command should be left OFF. In some countries, however, a Morse ID is required when packet is used and so the MID command should be enabled.

4.9.10 Sharing Packet Channels with Voice Operation

Although it is seldom needed, the PK-900 does have an input for SQUELCH information from a transceiver on the RADIO connectors. This input should be used and the SQUELCH command set if the packet channel is to be shared with voice operation.

4.9.11 Disabling Transmit Operation

Occasionally for test purposes it may be desired to disable the PTT circuit in the PK-900. This is done with the XMITOK Command.

4.10 Seldom Used Commands

The following commands operate in Packet, but are seldom needed. They are listed for reference and described in the Command Summary.

AFilter BBSmsgs CONPerm CPactime DCdconn Flow HEAderln MDMon MRpt MXmit

4.11 Packet Lite HF Packet Protocol Extension

Amateur radio needs a better communications mode for HF operation. Baudot and ASCII have no provision for error detection. AMTOR FEC and ARQ are more resistant to errors, but do not carry the full ASCII character set. 300 baud AX.25 packet is undesirable because the long transmissions are prone to bit errors, any one of which invalidate the whole frame. PACTOR is a recent protocol improvement.

Packet Lite is, as its name suggests, an abbreviated form of packet. It is designed as a transparent extension to the AX.25 protocol that reduces the "overhead" of all HF packet frames without digipeaters. Packet Lite does not solve HF packet's problems, but it should provide some throughput improvement on HF where it is desperately needed.

AEA's engineering department is interested in hearing from Packet Lite users with any comments or suggestions on improving the protocol.

A Brief Description of the Packet Lite Protocol

The main feature of Packet Lite that reduces overhead is that it uses an address field of only 4 bytes. A standard AX.25 header without digipeaters uses 14 bytes of addressing. Shortening the packet frame header lessens the possibility of any given frame taking a hit.

Packet Lite reduces the length of an I-frame slightly, but its real strength is the shortening of the acknowledgment frames, resulting in

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fewer garbled acks and therefore fewer unnecessary retries. An ack (RR, RNR or REJ frame) in standard AX.25 consists of 19 consecutive bytes that must be copied with no hits; Packet Lite reduces the length to 9 bytes, or 47% of the standard ack length.

A couple of restrictions are necessary to accomplish this. First, Packet Lite works only between two stations connected directly, with no digipeating allowed. If digipeaters are introduced to the address field, the advantage of the reduced overhead disappears.

Second, all Packet Lite connections emulate AX.25 version 2.0 (RR polling instead of retrying I-frames). This is necessary for the 10 minute identification described below. Also, the main reason version 1 continues to be used on HF is that on a retry a [RR,P] polling frame is so long that one might as well just send the I-frame again. Packet Lite's polling and ack frames are so short that the AX.25 version 2.0 polling method is now worth doing.

4.11.1 Enabling Packet Lite

To begin using Packet Lite, first make sure you have made all the proper HF Packet settings discussed earlier in this chapter. Be careful to ensure VHF is OFF and a 300 bps Modem has been selected.

Once these settings have been made, to enable the Packet Lite protocol extensions, turn the command LITE ON for the appropriate Port. For example to enable Packet Lite on Port 1, type "LITE ON" at the command prompt. You must not be connected to any other stations on that Port or you will not be allowed to change the LITE command.

Initiating a Packet Lite Connection

Once all the above settings have been made, simply issue the standard CONNECT request as described earlier in the chapter.

If the station you are connecting to also has Packet Lite enabled, a Packet Lite connection will result and you and the distant station should enjoy a more reliable QSO than others on the same frequency.

4.11.2 Compatibility With Standard AX.25 Stations

If the station you connect to does not have the Packet LITE protocol extensions, there are three known possibilities that will occur.

1. WA1ABC>WB2XYZ [C,P] 01 3E 38 58 32 {Packet Lite attempt} WB2XYZ>WA1ABC (UA,F) {Standard ack}

In this case, the non-Lite station sees the [C,P] control byte but ignores the non-standard bytes following it. It replies with a standard UA frame, and the connection proceeds as standard AX.25.

2. WA1ABC>WB2XYZ [C,P] 01 3E 38 58 32 {Packet Lite attempt} WB2XYZ>WA1ABC (FR): 3F 00 03 {Frame Reject} WA1ABC>WB2XYZ [C,P] {Standard attempt} WB2XYZ>WA1ABC (UA,F) {Standard ack}

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In this case, the non-Lite station notices the non-standard bytes following the control byte and issues a FRMR (Frame Reject) to signify that a protocol violation has taken place. The PK-900 receives the FRMR and automatically reverts to standard AX.25, sending the connect retries without the Lite PID and address bytes.

3. WA1ABC>WB2XYZ [C,P] 01 3E 38 58 32 {Packet Lite attempt} ... {No response}

In this case, the non-Lite station notices the non-standard bytes following the control byte but sends no response at all. If this occurs, you must turn the command LITE OFF and try to connect again to the distant station. No adverse effects are caused by this, but transparency with standard AX.25 is lost when the receiving station does not acknowledge a Packet Lite connect request in some manner.

We know that TCP/IP, NET-ROM and DRSI stations ignore Packet Lite Connect requests. These stations are normally found on VHF, but to be safe, the LITE command should be turned OFF when not in use.

4.11.3 Packet Lite Protocol Enhancement Summary

The following describes the Packet Lite protocol extension in depth for those interested in the technical details. It is not necessary to read or understand the following section to use the protocol. Here is a summary of a Packet Lite exchange, where WA1ABC calls WB2XYZ:

Connect: W B 2 X Y Z -0 W A 1 A B C -0 SABM 01 3E 38 58 32 destination | source | CTRL PID | short address

The destination and the source are both 7 bytes long. Everything up to the CTRL byte (SABM) is standard AX.25 version 2.0. The "Protocol ID" of 01 hex is Packet Lite's reserved value, which provides a way of interpreting the following bytes. This leaves room for other extensions to AX.25 in the future. The short address bytes are the right-justified bytes of the address field that WA1ABC proposes to use in subsequent Packet Lite frames with WB2XYZ. In this case, the AEA implementation of the short address is illustrated. 3E38 is a compressed version of the destination WB2XYZ and 5832 is a compression of WA1ABC. However, any combination of 26 bits may be used (see "Technical Details" below).

Connect acknowledgment: W A 1 A B C -0 W B 2 X Y Z -0 UA 01 58 32 3E 38 destination | source | CTRL PID | short address

WB2XYZ replies to WA1ABC. Again everything up to the CTRL byte (UA) is standard AX.25. The "PID" of 01 and the short address confirm that WB2XYZ has accepted the Packet Lite connection. The short address is again the right-justified representation of the address field that WB2XYZ will be using in subsequent Packet Lite transmissions. In this case WB2XYZ has accepted the short address field suggested by WA1ABC, and has shown his acceptance by echoing the address back in reverse order (5832 = WA1ABC and 3E38 = WB2XYZ). AEA products always accept the short address from the SABM frame; however, the Packet Lite protocol allows the sender of the UA frame to propose a different

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combination of 26 bits, to avoid conflicting with another Lite QSO. In either case, the sender of the original SABM must accept the 26 bits in the UA frame, reversing the address order for its own transmissions.

Transmission of data: 7C F0 B0 65 10 F0 Test <CR> 3E38 shifted 5832 shifted [I,P;0,0] short dest. short source CTRL PID text

WA1ABC sends data to WB2XYZ in Packet Lite format. The address field consists of the short address from WB2XYZ's UA frame, reversed and left-shifted. The added bits come from AX.25 version 2.0's command and response bits, and the end-of-address bit.

Acknowledgment of data: B0 64 7C F1 31 5832 shifted 3E38 shifted (RR,F;1) short dest. short source CTRL

WB2XYZ acknowledges the data from WA1ABC. The address field is reversed. This is the shortest length frame possible in Packet Lite. 4 address bytes + 1 CTRL byte + 2 flags + 2 CRC bytes = 9 bytes.

Every 10 minutes the stations must identify using both long and short addresses:

W B 2 X Y Z -0 W A 1 A B C -0 [RR,P;0] 01 3E 38 58 32 destination | source | CTRL PID | short address

W A 1 A B C -0 W B 2 X Y Z -0 (RR,F;1) 01 58 32 3E 38 destination | source | CTRL PID | short address

Either station may initiate the ID exchange.

Disconnect: W B 2 X Y Z -0 W A 1 A B C -0 DISC 01 3E 38 58 32 destination | source | CTRL PID | short address

Disconnect acknowledgment: W A 1 A B C -0 W B 2 X Y Z -0 UA 01 58 32 3E 38 destination | source | CTRL PID | short address

At the end of the connection, the two stations must once again identify using both long and short addresses.

AEA firmware supporting Packet Lite also contains code that permits monitoring of Packet Lite and extended AX.25 frames.

Packet Lite Shortened Address Technical Details

The Packet Lite address field consists of 26 bits distributed over 4 bytes (or octets, as the AX.25 specification calls them). These bits are considered to be two groups of 13 bits each, roughly equivalent to a destination and a source ID. If we label the bits A-Z and show their use in the address field of a Lite frame, the bits are distributed as follows:

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A B C D E F G 0 x H I J K L M 0 N O P Q R S T 0 y U V W X Y Z 1

The least significant bit of each byte is used to show whether or not the byte is the final byte in the address field, as in standard AX.25. The bits "x" and "y" (lower case) have the function of command and response, similar to the function of the standard AX.25 version 2.0 SSID byte C bits (see AX.25 Protocol version 2.0, section 2.4.1.2).

In the AEA implementation of Lite addressing, the standard callsigns are compressed to yield short addresses. The destination callsign is compressed into bits A-M, and the source into N-Z. These bits are used as the address field suggestion following the control byte in the Connect (SABM) frame. When the bits are used following the control byte as an ID suggestion or a real extended ID, the format is:

0 A B C D E F G 0 0 H I J K L M 0 N O P Q R S T 0 0 U V W X Y Z

If we label the 7 standard right-justified callsign bytes 1-6 and SSID, here is how we derive the first group of address bits A-M:

ABCDE = (byte 1 XOR byte 4) AND $1F FGHI = (byte 2 XOR byte 5) AND $0F JKLM = (byte 3 XOR byte 6 XOR SSID) AND $0F

AEA firmware derives the second group of bits N-Z the same way. Other implementations are free to select any combination of 26 bits when setting up the short address in either the initial SABM frame or its UA response.

4.12 Packet Meteor Scatter Extension

A new packet protocol extension has been added for meteor scatter work that allows a Master/Slave packet connection to be established. This is done to reduce the possibility of simultaneous transmissions by both sides of a packet connection over a long meteor scatter path.

This experimental protocol is activated by turning User BIT 18 ON (UBIT 18 ON). When UBIT 18 is ON (default OFF) the packet station who initiates a packet connect will become the Master station and the station who acknowledges the connect becomes the Slave.

After a Meteor Scatter connection has been established, the Master station will continually send either information frames (I-frames) or polling frames and await an acknowledgement from the slave. The Master station therefore sends packets constantly, even if all its I-frames have been acknowledged. The slave station sends nothing, not even I-frames, until it receives a polling frame from the master. The Slave station may only send an I-frame to the Master after a poll frame has been received.

The packet timing of the Master station is critical for proper Meteor Scatter operation. In a normal AX.25 packet connect, the FRACK timer counts down until it reaches zero and then a Retry of a poll frame is sent. The FRACK timer counts in units of seconds however and a finer timing resolution is desirable for Meteor Scatter work. A new timer called FRICK has been added which times in 10 mSec increments. The

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FRICK timer can be set from 0 (disabled) to 250 which corresponds to a time of up to 2.5 Seconds. See the Command Summary for a complete description of the FRICK timer.

The following settings are recommended for this method of Meteor Scatter work. Both packet stations should use these same settings.

UBIT 18 ON RETRY 0 AX25L2V2 ON (default) MAXFRAME 1 (CHECK doesn't matter) FRICK n, where n is large enough to allow the other station time to send the start of an acknowledgement frame

Note: Do not operate the unit with multiple packet connections while FRICK is active (1-250). In contrast to FRACK, which provides one retry timer per multi-connect channel, there is only one FRICK timer on each radio port of the PK-900. Each logical channel will try to use the same FRICK timer, causing interference to the operation of the other channels.

Digipeaters should not be used when in the Meteor Scatter mode. The FRICK timer (unlike FRACK) does not allow any extra time when digipeater stations are specified.

To return to normal AX.25 packet operation turn User BIT 18 OFF. Also, be sure to disable the FRICK timer (by setting FRICK to 0) when you are through operating in Meteor Scatter mode.

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This page is used to make the number of pages in this chapter an even number.

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CHAPTER 5

MAILDROP OPERATION

5.1 Overview of MailDrop Operation

The PK-900's MailDrop is a personal mailbox that uses a subset of the well-known W0RLI/WA7MBL packet BBS commands allowing messages to be automatically sent and received. The MailDrop operates in Packet, AMTOR and PACTOR modes and may be accessed from both Radio Ports, although not simultaneously. This allows message traffic to move from Packet to AMTOR or PACTOR and vice versa.

When your MailDrop is active, distant stations can connect (in Packet) or Link (in AMTOR/PACTOR) to your PK-900, leave messages for you or read messages from you. If you choose to allow it, any station may leave messages for any other station simply by turning the parameter 3RDPARTY ON.

The Maildrop also supports forwarding and reverse forwarding of Packet messages if properly coordinated with a local "full service" BBS. Hierarchical message addressing is supported to simplify the routing of both national and international traffic.

5.1.1 RAM Space for Message Storage

Approximately 17K bytes of RAM are available to your MailDrop. RAM space is dynamically allocated so that it is possible to store as many messages as you like until all the memory is filled. If all 18K of RAM is used, the MailDrop displays the message "*** No free memory".

5.1.2 System Commands

MailDrop operation is completely under your "SYSOP" control from your local terminal or computer keyboard. Only you can start and stop MailDrop service. The commands shown below provide MailDrop control.

5.1.3 Your MailDrop Callsign

When operating in Packet, your MailDrop can have its own callsign which you enter with the MYMAIL command. If you do not enter a callsign in MYMAIL, the MailDrop will use MYCALL when it is enabled. When operating the MailDrop in AMTOR, your 4 character MYSELCAL or 7 character MYIDENT is used and must be entered for remote users to access the MailDrop. Se the command summary (Appendix A) for information on how to set MYSELCAL and MYIDENT

5.1.4 Start and Stop MailDrop Operation

Set MAILDROP to ON to start Packet MailDrop operation (default is OFF). This command activates or deactivates your Packet MailDrop. Set TMAIL ON to start AMTOR/PACTOR MailDrop operation. Again, the default is OFF.

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5.2 Local Logon

If you are using PC PACKRATT or some other host mode program, follow the instructions for the program. If you are using a terminal or terminal program the following sections apply.

Type MDCHECK to verify that you have local control of the MailDrop. You must not be connected or linked to any other stations to be able to do this.

Once logged on to your MailDrop from your local keyboard, you are shown the MailDrop prompt as though you were the calling station:

[AEA PK-900] 17396 free (B,E,K,L,R,S) >

You can now EDIT, KILL, LIST, READ or SEND messages. The number "17396 free" is the RAM available for MailDrop messages.

While you're "logged on" to your MailDrop, a connect request from another station will cause the PK-900 to send the "BUSY" frame. In AMTOR, the PK-900 simply ignores ARQ link requests while you are logged on to your MailDrop. When you are finished using the MailDrop, type "B" (BYE) to "log off". This returns the PK-900 to normal operation and makes your MailDrop available to other stations.

In Packet mode, you must leave the MAILDROP command ON if you wish to make it available for others. No other stations can reach your MailDrop unless the MAILDROP command is turned ON. In AMTOR, TMAIL must be ON.

You have full control of your PK-900 while the MAILDROP is ON. You can connect to others and carry on normal QSOs using the call sign in MYCALL provided you have entered a separate MYMAIL MailDrop callsign.

5.2.1 Monitor MailDrop Operation

Set MDMON to ON to monitor other stations' use of your MailDrop. Set MDMON OFF (default) to cancel MailDrop monitoring. User bit 13 allows MailDrop connect and status messages to be disabled as well. See the UBIT command in the command summary for specifics.

The MDMON command permits you to monitor a station's activity on your MailDrop showing you both sides of the QSO. Packet headers are not shown while a caller is connected to your MailDrop. When a caller is connected to the MailDrop, MCON determines what packets are monitored. When your MailDrop is idle, MONITOR determines what packets are seen.

5.2.2 Caller Prompts

MTEXT is the MailDrop connect-message prompt sent to a packet station connecting to the MailDrop if MMSG is ON. The default message is:

"Welcome to my AEA PK-900 maildrop. Type H for help."

MDPROMPT is the Message prompt sent to a station by the MailDrop. This prompt is given to a station sending a message. You can enter

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any text with a maximum length of 80 bytes. The default prompt is:

"Subject:/Enter message, ^Z (CTRL-Z) or /EX to end"

You may wish to enter a CTEXT message announcing the presence of a mailbox and the call sign (MYMAIL) used to access your MailDrop.

5.3 SYSOP MailDrop Commands

While you have logged on to your MailDrop from your local keyboard with the MDCHECK command, the commands available to you are:

B, E, K, L, R, S.

These are the "standard" BBS commands available to the MailDrop SYSOP. Any other command sent by you is answered with the error message "*** What?". A brief description of each command follows. All the available commands are described in detail following the next section.

B BYE Log off the MailDrop E EDIT Edit a MailDrop message K KILL Kill or delete messages L LIST List the message directory R READ Read a specific message S SEND Send a message

5.4 Remote User MailDrop Commands

When a remote user has logged on to your MailDrop the following commands will be available to the distant station:

A, B, H, J, K, L, R, S, V, ?.

A brief description of each command follows. These MailDrop commands are described in detail in the next sections.

A ABORT Aborts the reading of a long message B BYE Log off the MailDrop H HELP Help for the MailDrop commands J JLOG Sends the PK-900 MHeard list K KILL Kill or delete messages L LIST List the message directory R READ Read a specific message S SEND Send a message V VERSION Sends the PK-900 sign-on message ? HELP Help for the MailDrop commands

5.4.1 A (ABORT) (Remote only)

The "A" command aborts the Listing or Reading of messages by a calling station. This is handy if the remote user decides not to continue reading a long message. The message "*** Done" followed by the MailDrop prompt will be sent after an Abort has been received. On the local terminal the SYSOP may type the CANLINE character (default <CTRL-X>) to abort a long screen dump.

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5.4.2 B (BYE)

The "B" command (Host abbreviation B1) logs the calling station (and you) off the MailDrop. A calling station will be disconnected; you will see the standard PK-900 "cmd:" prompt. The calling station may also simply disconnect.

5.4.3 E (EDIT #) (SYSOP only command)

The Edit command (Host abbreviation E1) is a powerful tool for controlling the status of messages on your MailDrop. The SYSOP must access the MailDrop before typing this command. Here are all possible ways to use this command:

E Shows the following short help file: E msg# E msg# B/T/P E msg# Y/N/F E msg# >/</@ callsign

E 12 Shows message 12's info line. E 23 > W0RM Sets "W0RM" as message 23's destination. E 35 < WH1Z Sets "WH1Z" as message 35's source. E 48 @ N7ML Sets "N7ML" as message 48's destination BBS. E 49 @ N7ML.MT.NA Sets "N7ML" as message 49's destination BBS. and adds the hierarchical forwarding information .MT.NA signifying that N7ML BBS is located in the state of Montana (MT) which is located in North America (NA). E 58 @ Clears message 58's destination BBS field. E 60 P Sets message 60's status to Private. E 61 B Sets message 61's status to Bulletin. E 62 T Sets message 62's status to Traffic. E 63 Y Sets message 63's status to Has-Been-Read. E 64 N Sets message 64's status to Has-Not-Been-Read. E 49 F Sets message 49's status to Reverse Forward.

The command "E n F" sets the message status to enable Reverse Forwarding of a message number. To cancel forwarding, set the status to either "Y" or "N." Please read the section on Reverse Forwarding (below) if you are interested in this feature.

5.4.4 H (HELP) (Remote only command)

The "H" command sends the distant station a HELP list of all available MailDrop commands as shown below. The "?" will also cause the HELP file to be sent.

A(bort) Stop Read or List B(ye) Log off H(elp) Display this message J(log) Display stations heard K(ill) K n: Kill message number n KM : Kill messages you have read L(ist) L : List message titles

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LM : List messages to you R(ead) R n: Read message number n RM : Read all your unread messages S(end) S : Send a message to SYSOP S n: Send a message to station n V(ersion) Display TNC firmware version ? Same as H(elp)

5.4.5 J (JLOG) (Remote only command)

The "J" command sent by the distant station will cause your MailDrop to send the PK-900's MHEARD List to the station. This command is not available to you the SYSOP since you can simply enter MHEARD at the PK-900 command prompt.

5.4.6 K n (KILL n [Mine])

The "K n" command (Host abbreviation K1) deletes message number "n" from the MailDrop. As SYSOP, you can kill any message. A calling station can kill only messages addressed to or from that station. Messages are killed by number, not call sign. The remote user may enter the "KM" (Kill Mine) command to KILL all of his or her messages that have been read previously.

5.4.7 L (LIST [Mine])

The "L" command (Host abbreviation L1) shows you the SysOp a list of ALL active messages on the MailDrop. The list is preceded by the following column header:

Msg# Size To From @ BBS Date Time Title

All active messages are listed under this line with the most recent message first. DAYTIME must be set for the Date and Time to appear.

When a remote user types the LIST command, the MailDrop lists only the messages that user may read, including messages to "ALL" and "QST." Messages to other users are not displayed. The MailDrop accepts the LM (List Mine) command from the remote user. This command acts only on messages addressed to the remote user, not messages to "ALL" or "QST."

5.4.8 R n (READ n [Mine])

The "R n" command (Host abbreviation R1) displays the header and text of message number "n". Messages are read by number, not call sign. As SYSOP, you can read all messages. A remote user may READ only messages addressed to his call sign, or to "ALL" or "QST". The Mail Drop accepts the RM (Read Mine) command from remote users. This command acts only on messages addressed to the remote user, not messages to "ALL" or "QST." The RM command displays only messages that have not been read previously.

5.4.9 S callsign (SEND callsign)

The "S callsign" command (Host abbreviation S1) notifies the MailDrop that either you as SYSOP or the calling station will now send text into a message. 1/93 5-5

If 3RDPARTY is ON, then the calling station can leave a message for a station other than the SYSOP. If the station attempts to leave third party traffic with 3RDPARTY OFF, then the calling station will see:

*** No 3rd party traffic. [AEA PK-900] 17396 free (A,B,H,J,K,L,R,S,V,?) >

If all 17K of the RAM is used, the MailDrop displays the message "*** No free memory". If there is room, the MailDrop displays the Subject request message prompt:

"Subject:"

Enter a short (up to 27 character) description of the subject of the message. The MailDrop will then send the message prompt:

"Enter message, ^Z (CTRL-Z) or /EX to end"

After entering the message there are two ways to end the message. Either the <CTRL-Z> may be entered followed by a carriage return, or the 3 characters "/EX" and a carriage-return on a line by itself will end the message being sent. After this the MailDrop prompt should appear indicating that the MailDrop is ready for another command.

After ending the message, if you or the calling party see the message "*** No free memory", this means that the message was too large for the available MailDrop memory and has been deleted. If this occurs, you must shorten the message to fit into available memory shown in the MailDrop prompt, and re-send the message.

When logged on from your local keyboard, if you use the "S" command without a call sign, you'll see the error message "*** Need callsign" However, a calling station may use the S command without a callsign; it is understood that the message is directed to the PK-900's SYSOP.

As soon as a calling station uses the S command to send you (the SYSOP) a message, the MAIL LCD starts blinking to show that a message has been left for you. When you log on to your MailDrop with the MDCHECK command the MAIL LCD will stop blinking.

5.4.9.1 Sending Other Types of Messages with SEND

Each message in the PK-900 MailDrop has a flag to show whether it is Private, Traffic or a Bulletin. A "P," "T" or "B" after the message number shows the status of every message. A user sets this with the SP, ST and SB forms of the Send command. The SYSOP may set this with the Edit (E) command described above. If only S is used as the Send command, the MailDrop will assign the message a Private (P) status.

A Private message can be listed, read and killed only by the reciepient or sysop. Bulletins are listable and readable by all and may be killed by only the originator or sysop. Traffic is handled much like private messages but are intended for BBS handling. The PK-900 MailDrop also accepts SEND commands of the form "SP SYSOP < W1AW." The call sign after the "<" goes into the "From" field of the message header.

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For example, your MailDrop accepts the following additional information in a Send command:

S N7ML @ K6RFK < N6IA

The above means you want to send a message to N7ML who uses the K6RFK Bulletin-Board and the message is from N6IA.

The PK-900 MailDrop accepts hierarchical forwarding information that is helpful in reverse forwarding to full service BBS stations. An example of this is shown below:

SP N7ML @ K6RFK.WA.NA

The above means that you want to send a message to N7ML who uses the K6RFK Bulletin-Board which is located WAshington which is located in North America.

The PK-900 MailDrop also supports BIDs (Bulletin IDs). This support is required for Reverse Forwarding (see below). The BID begins with a "$" character and is sent and received in the Send command line:

S N7ML @ K6RFK < N6IA $345_KB7B

With the PK-900 MailDrop you may also use just the "$" all by itself as shown in the two examples below:

S N7ML @ K6RFK < N6IA $ or S ALL $

In this case, the PK-900 MailDrop will assign its own BID to these messages.

5.4.10 V (VERSION) (Remote only command)

The "V" command causes the PK-900 to send the sign-on message and firmware date to the remote user only.

5.4.11 ? (HELP) (Remote only command)

The "?" command sends the distant station a HELP list of all available MailDrop commands shown above under the "H" command. Both the "?" and the "H" cause this same file to be sent to the remote user.

5.5 Sample MailDrop Session - The Remote User's Point of View

Let's see what the MailDrop looks like to a calling station. Let's assume that your call is "WX1AAA", and that you wish to connect and log on to "WX2BBB's" MailDrop system. During your session on his MailDrop, you wish to list the messages to see if there is a message for you, read it if it exists, kill it after you're done reading it, send a return message to WX2BBB and finally log off or disconnect from his MailDrop.

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5.5.1 Connect and Logon

From the cmd: prompt, type the usual connect request:

cmd:c wx2bbb {Connect request} *** CONNECTED to WX2BBB {PK-900 status line}

You have mail {informs the user mail is waiting} [AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

5.5.2 LIST Messages

You're logged on and have gotten the MailDrop's prompt:

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

Now, type "L" to LIST all the messages in the MailDrop.

L {The LIST command} {The MailDrop responds} Msg# Size To From @ BBS Date Time Title 6 PN 184 WX1AAA WX2BBB 01-Jun-90 20:15 Hello Joe 5 BY 287 ALL WX2BBB 01-Jun-90 18:42 Question 4 BY 178 QST WX2BBB 01-Jun-90 17:30 Mailbox 1 BY 56 ALL WX2BBB 01-Jun-90 10:22 APLINK [AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

5.5.3 READ Messages

You've seen the list of messages and wish to READ yours. You've seen the MailDrop's prompt:

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

Now, type "R #" to READ the one message number to you in the MailDrop.

R 6 {The READ 6 command} {The MailDrop responds} Msg# Size To From @ BBS Date Time Title 6 PN 144 WX1AAA WX2BBB 01-Jun-90 20:15 Hello Joe {The message header} Hello Joe. Did you get the notice {The message} about next month's meeting of the Radio Society at the Firehouse? Will you be going? - I need a ride.

73.

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

5.5.4 KILL Messages

You've read the message addressed to you and wish to KILL it. Again you see the MailDrop's prompt:

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

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Now, type "K #" to KILL one specific message in the MailDrop.

K 6 {The KILL 6 command} *** Done. {MailDrop confirms} [AEA PK-900] 16704 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

5.5.5 SEND Messages

You've killed the message and wish to SEND a reply to the MailDrop's operator, WX2BBB. Again you see the MailDrop's prompt. Remember the number after the right bracket "]" shows you how much memory space is available in the MailDrop. Always verify that the MailDrop has enough memory remaining for the length of message you intend to send.

[AEA PK-900] 16704 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

Now, type "S [callsign]" to SEND a message to the MailDrop's SYSOP. If you omit the call sign, the MailDrop will address the message to the MYMAIL or MYCALL call sign. Messages sent with the S command are considered Private unless they are sent to "ALL" or to "QST".

S WX2BBB {The "SEND callsign" command} Subject: {MailDrop's Subject prompt} I WILL BE GOING {Your subject entry} Enter message, ^Z (CTRL-Z) or /EX to end {MailDrop answers you}

YEAH, I GOT THE MAILING AND WILL {Type your message to WX2BBB} BE GLAD TO PICK YOU UP. WHAT TIME DO YOU WANT ME THERE? IS MARY GOING? CUL. WX1AAA /EX {End the message with /EX}

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

NOTE: If the message was ended with the "/EX", the last line will contain a "/E" when the message is read. To avoid this, use the <CTRL-Z> to end messages.

5.5.6 Log Off and Disconnect

You're finished with this session. Time to log off the MailDrop.

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > {MailDrop's prompt}

Now, type "B" (for Bye) to LOG OFF the MailDrop.

B {The Bye command}

The MailDrop issues an immediate disconnect command to your PK-900 and the connection is over.

*** DISCONNECTED {PK-900's status line}

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5.6 Sample MailDrop Session - MailDrop SYSOP's Point of View

Here is a transcription of the entire session described in the previous section, exactly as it would appear to the MailDrop's operator (SYSOP). We're assuming that the MDMON command is set to ON.

When MDMON is ON, you have the ability to supervise the activities of any station logged on to your MailDrop and - if needed - take any corrective action.

WX1AAA>WX2BBB <C,P> You have mail [AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > *** CONNECTED to WX1AAA (Maildrop)

L Msg# Size To From @ BBS Date Time Title 6 PN 184 WX1AAA WX2BBB 01-Jun-90 20:15 Hello Joe 5 BY 287 ALL WX2BBB 01-Jun-90 18:42 Question 4 BY 178 QST WX2BBB 01-Jun-90 17:30 Mailbox 1 BY 56 ALL WX2BBB 01-Jun-90 10:22 APLINK [AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > R 6 Msg# Size To From @ BBS Date Time Title 6 PN 184 WX1AAA WX2BBB 01-Jun-90 20:15 Hello Joe

Hello Joe. Did you get the notice about next month's meeting of the Radio Society at the Firehouse? Will you be going? - I need a ride.

73.

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > K 6 *** Done. [AEA PK-900] 16704 free (A,B,H,J,K,L,R,S,V,?) > S WX2BBB Subject: I WILL BE GOING Enter message, ^Z (CTRL-Z) or /EX to end

YEAH, I GOT THE MAILING AND WILL BE GLAD TO PICK YOU UP. WHAT TIME DO YOU WANT ME THERE? IS MARY GOING? CUL. WX1AAA /EX

[AEA PK-900] 16508 free (A,B,H,J,K,L,R,S,V,?) > B *** DISCONNECTED

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5.6.1 Message Numbers

Any message that is sent to the PK-900 MailDrop by a remote user or you, the SYSOP, is given a message number. Message numbers start at 1 and over time work their way up to 999 and then wrap back around to 1 again. Sometime it is desirable to reset the message counter. This can be done with the LASTMSG command which is described in the Command summary.

5.7 Forwarding and Reverse Forwarding with the PK-900 MailDrop

Forwarding allows your large community Bulletin Board System (BBS) to automatically connect to your MailDrop and send messages to you. Similarly, Reverse Forwarding allows your community BBS to connect to your MailDrop and get messages you wish to send to others.

Forwarding and Reverse Forwarding (or simply Auto-Forwarding) can be an advantage in a local area. The community BBS can be set to connect to your MailDrop at times when local traffic is low, such as late at night. This can spread out the traffic volume on a packet frequency which can become quite heavy in the "prime time" early evening hours.

Auto-Forwarding is involved and requires the cooperation of both you and your community BBS Operator. Not all large BBSs will forward to individual users. Some packet frequencies are so busy forwarding to other BBSs that they can not forward to individuals. You must contact the community BBS SYSOP to determine the guidelines in your area.

5.7.1 MailDrop Settings for Auto-Forwarding

The following must all be set properly for Auto-Forwarding to operate.

- Enter your MYCALL. Enter your MYMAIL if you desire to use a separate call sign for the MailDrop.

- Make arrangements with your local BBS SYSOP to Auto-Forward to your MailDrop. Make sure you let the him know the MailDrop call sign you will use. The BBS SYSOP must program his system to connect to your MailDrop or Auto-Forwarding will not function.

- Enter the call sign of this community BBS in the HOMEBBS command.

- Leave your PK-900 and radio ON THE AIR so that your local BBS can connect to your MailDrop. If your packet station is not on when the local BBS tries to connect, the advantage of Auto Forwarding is lost and the BBS SYSOP may drop you from the Forwarding list.

Once the above have been completed, you are ready to receive messages automatically from your local BBS. The next section describes how to prepare messages for Reverse Forwarding to the local BBS (HOMEBBS).

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5.7.2 Entering a Message for Reverse Forwarding

To prepare a message for Reverse Forwarding to another station:

- Type MDCHECK to access your MailDrop from your terminal.

- Using the Send command, type the message you want forwarded. Use the "@" field to set the destination BBS where the addressee will pick up his mail. For example if you want to send a message to N6UND who you know uses the BBS N6IIU enter the following:

S N6UND @ N6IIU.CA.NA

Note that the "@" call sign does not need to be the same as the HOMEBBS call sign. The "@" call sign can be typed as part of the Send command or as part of the Edit command described earlier. The ".CA.NA" is optional "Hierarchical forwarding" information that in this case designates that N6IIU is located in the state of California.

- Enter the Subject and text of the message as described above in the Send command section. Don't forget to end your message with <CTRL-Z> or "/EX" on its own separate line also described above.

- Use the Edit command to set the Forwarding flag for each message that will be Reverse Forwarded to HOMEBBS. This is described in the Edit command section above. For example the following will mark message number 53 for Reverse Forwarding.

E 53 F (Sets Reverse Forwarding for message 53.)

- Log off your MailDrop with the B (Bye) command.

- If you wish each message to disappear as it is Reverse Forwarded, leave KILONFWD ON. If you wish to keep each message after it has been Forwarded, turn KILONFWD OFF. After forwarding, the message flag will change from "F" to "Y" to show that it has been read.

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CHAPTER 6

BAUDOT AND ASCII RTTY OPERATION

6.1 Overview

Baudot (pronounced Baw-dough) has been in use for many years. The five bit Baudot/Murray code was the basis of the Western Union Telex service and Baudot RTTY (Radio TeleTYpe) is still widely used on the HF amateur bands. The Baudot character set contains the upper-case letters, the numbers 0-9 and some common punctuation characters. Because Baudot has only five bits, it is less prone to errors than seven bit ASCII. Your PK-900 provides Baudot RTTY at all standard speeds in use today, including commercial speeds up to 300 bauds.

ASCII (pronounced Ask-kee), the American Standard Code for Information Interchange has been in use for nearly 30 years. ASCII is a 7-bit code and was designed to overcome the limitations of the Baudot character set by including both upper and lower case letters, numbers, all punctuation as well as many computer control codes. ASCII is not as popular on the amateur bands, but its operation is almost identical to Baudot RTTY so we will describe them both in this chapter.

Baudot and ASCII may be operated on Radio Port 1 on the PK-900. Packet may be used on Radio Port 2 at the same time, so you won't miss any connects while operating Baudot or ASCII on HF.

6.2 Where to Operate Baudot and ASCII RTTY

Before you can operate Baudot or ASCII RTTY, you must first know where the activity is. Most RTTY operation occurs on the 20-meter amateur between 14.08 and 14.10 MHz. RTTY activity can be found on the other HF amateur bands as well and is most often located between 80 and 100 kHz up from the bottom of the band as it is on 20 meters.

6.2.1 PK-900 Baudot RTTY Parameter Settings

First you must enter the Baudot mode of the PK-900. If you are using an AEA PAKRATT program, follow the instructions in the program manual to enter the Baudot mode.

If you are using a terminal, simply type "BAUDOT" or "BA" from the Command Mode followed by the <Enter> key to enter the Baudot mode. The PK-900 responds by displaying the previous mode:

Opmode was PAcket Opmode now BAudot

Your PK-900's front panel LCD display will show the Baudot operating mode on Radio Port 1 and the SYSTEM COMMAND LCD will also be on.

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The following parameters are the most common settings for HF Baudot operation. Check the parameters and make sure they are set as follows:

RBAUD 45 (this is the most common amateur speed on HF) RXREV OFF TXREV OFF MODEM 1

Note: The command, QRtty, will automatically select a modem when you enter the Baudot or ASCII mode.

6.2.2 HF Receiver Settings

Set your HF receiver (or transceiver) to Lower Sideband (LSB) unless you connected your PK-900 through the direct FSK keying lines. In this case, you should select the FSK operating mode. Adjust the volume to a comfortable listening level.

6.2.3 Tuning in Baudot and ASCII Stations

Tuning in Baudot and ASCII stations properly is critical to successful operation. Since HF Baudot and RTTY stations use either 170 Hz or 200 Hz Frequency Shift Keying to send data, tuning accuracy is very important. The command BARgraph will select the type of tuning display. (See below.) Follow the tuning procedure below carefully for the best results in tuning HF Baudot and ASCII stations.

o Make certain your HF receiver is either in LSB or FSK.

o Turn any IF-Shift and Passband-Tuning controls to the Center or OFF position.

o Tune your receiver carefully between 14.08 and 14.10 MHz (or another band where you know there is Baudot or ASCII activity) and listen for RTTY stations.

o When you find a station, slowly vary the VFO tuning knob on your receiver and look for a display on the PK-900 tuning indicator like the one shown below.

—————————————————————————————————————————————————————————————— MARK |       | SPACE —————————————————————————————————————————————————————————————— Tuning correct for discriminator indicator (BAR 0)

—————————————————————————————————————————————————————————————— |                 | —————————————————————————————————————————————————————————————— Tuning correct for magic eye indicator (BAR 3)

—————————————————————————————————————————————————————————————— |   | —————————————————————————————————————————————————————————————— Tuning correct for center tune indicator (BAR 2)

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