Vertex Standard VX-900 User Manual

VX-900

BCD13

679

UHF Band

Service Manual

VERTEX STANDARD CO., LTD.

4-8-8 Nakameguro, Meguro-Ku, Tokyo 153-8644, Japan

VERTEX STANDARD

US Headquarters

10900 Walker Street, Cypress, CA 90630, U.S.A.

International Division

8350 N.W. 52nd Terrace, Suite 201, Miami, FL 33166, U.S.A.

YAESU EUROPE B.V.

P.O. Box 75525, 1118 ZN Schiphol, The Netherlands

YAESU UK LTD.

Unit 12, Sun Valley Business Park, Winnall Close Winchester, Hampshire, SO23 0LB, U.K.

VERTEX STANDARD HK LTD.

Unit 5, 20/F., Seaview Centre, 139-141 Hoi Bun Road, Kwun Tong, Kowloon, Hong Kong

Introduction

This manual describes the circuit theory, programming procedures, and alignment procedures for the VX-900 UHF Portable Transceiver.

Much of the operating flexibility of the VX-900 is derived from its versatile "Soft Key" front panel keys. These keys may be configured for a number of operating functions, as described in this manual.

Following the discussion of transceiver operation, details regarding programming software, alignment, and maintenance will follow.

Operating Manual Reprint ................................................................................................................................................2

Set (Menu) Mode Functions............................................................................................................................................10

Cloning................................................................................................................................................................................12

Specification.......................................................................................................................................................................13

Exploded Views & Miscellaneous Parts .......................................................................................................................14

Block Diagram ...................................................................................................................................................................15

Circuit Description ...........................................................................................................................................................17

Alignment...........................................................................................................................................................................20

Test Adapter Schematic ...................................................................................................................................................25

Board Units (Schematics, Layouts & Parts)

MAIN Unit......................................................................................................................................................................27

VR Unit ............................................................................................................................................................................ 55

SW Unit ........................................................................................................................................................................... 56

Dummy Unit .................................................................................................................................................................. 57

Optional Board Units (Schematics, Layouts & Parts)

F2D-8 2-Tone Decode Unit ........................................................................................................................................... 58

VTP-50 VX-Trunk Unit ................................................................................................................................................. 60

FVP-25 Encryption / DTMF Pager Unit ...................................................................................................................... 62

F5D-14 5-Tone Unit ....................................................................................................................................................... 64

Operating Manual Reprint

CONTROLS & CONNECTORS

LCD (Liquid Crystal Display

SIDE SEL Key

PTT Switch

MONITOR Button

LAMP Button

CH (Channel) Selector

Antenna Jack

TOP SEL Key

)

Speaker

LED Indicator

Steady Green: Signaling off Blinking Green: Busy Channel (or SQL off) Steady Red: Transmission in Progress Blinking Red: Battery voltage is low

VOL/PWR Knob TOGGLE Switch

MIC/SP Jack

(

External MIC/SP

Sub Microphone

(

Noise Canceling Microphone

)

16-Button DTMF Keypad

(

16-key version only

Low Transmit Power Mode On

This Channel on “DUAL WATCH” List

This Channel on “SCAN” List

)

Battery Pack Latch

LCD ICONS & INDICATORS

Talk-Around Mode

8 Charactor Alpha-numeric Invertible Display

Main Microphone

Receive Monitor

Steady On: Signal off Blinking: Busy Channel (or SQL off)

Channel Group Number (

“01” ~ “19” and “0”

Group Scan Enabled (this group)

)

Operating Manual Reprint

BEFORE YOU BEGIN

Battery Pack Installation and Removal

To install the battery, hold the transceiver with

your left hand, so your palm is over the speaker and your thumb is on the top of the belt clip. Carefully mate the battery four insertion slots with their corresponding alignment tabs on the transceiver case, while tilting the Belt Clip outward. Proper alignment occurs with the battery pack offset about 1/2 inch from the top edge of the battery compartment. Guide the pack to the tabs with a slight inward

pressure, then slide the battery pack upward, until it locks in place with a “Click.”

Tilt the Belt Clip

OPERATION

Preliminary Steps

Install a charged battery

pack onto the transceiver, as described previously.

Screw the supplied antenna

onto the Antenna jack. Never attempt to operate this transceiver without an antenna connected.

If you have a Speaker/Mi-

crophone, we recommend that it not be connected until you are familiar with the basic operation of the VX-900.

Operation Quick Start

Turn the top panel’s VOL/

PWR knob clockwise to turn on the radio on.

Insert the Battery Pack

To remove the battery, turn the radio off and re-

move any protective cases. Slide the Battery Pack Latch on the bottom of the radio toward the front

panel while sliding the battery down about 1/2 inch. Then lift the battery out from the radio while unfolding the Belt Clip.

Do not attempt to open any of the rechargeable Lithium-Ion pack, as they could explode if accidentally short-cir-

cuited.

Low Battery Indication

As the battery discharges during use, the voltage gradually becomes lower. When the battery voltage reaches 6.0 volts, it is time to substitute a freshly charged battery and recharge the depleted pack. The LED indicator on the top of the radio will blink red when the battery voltage is low (6 Volts or lower).

CAUTION

Danger of explosion if battery is incorrectly replaced. Replace only with the same or equivalent type.

Turn the top panel’s CH

selector knob to choose the desired operating channel. A channel name will appear on the LCD. If you want to select the operating channel from a different Memory Channel Group, pressing the Soft key (assigned to the Memory Group Up or Down function) to select the Memory Channel Group to be you want before selecting the operating channel. A group name will appear on the LCD whenever the Soft key is pressed.

Note: Some models are programmed so that the operating channels are selected by the Soft key and the memory channel group is selected by the channe selector knob. For further details, contact your VERTEX STANDARD dealer.

Rotate the VOL/PWR

knob to set the volume level. If no signal is present, press and hold in the MONITOR button (under the PTT switch) more than 2 seconds; background noise will now be heard, and you may use this to set the VOL/PWR knob for the desired audio level. Press and hold the MONITOR button more than 2 seconds (or press the MONI-

Operating Manual Reprint

TOR button twice) to quiet the noise and resume normal (quiet) monitoring.

To transmit, press and

hold the PTT switch. Speak into the microphone area of the front panel grille (above the [D]

key) in a normal voice

level. To return to the Receive mode, release the PTT switch.

Press the Soft key (if assigned to the Scan func-

tion) or switch the TOGGLE Switch to the assigned “Scan” position (when so programmed by your dealer) to start the scanner. The scanner rapidly steps through each of the dealer-programmed channels, looking for incoming calls.

Press the TOP SEL key

(on the top panel) or SIDE SEL key (the top button on the left side) to activate one of the preprogrammed functions which may have been enabled at the time of programming by the dealer. Similarly, when using the 16-key version, the [A], [B], [C], and [D function keys activate one of these functions, if programmed by the dealer. See the next section for details regarding the available features.

]

r Switch the top panel’s

TOGGLE switch to the [A], [B] or [Center] position to activate one of the pre-programmed functions which may have been enabled at the time of programming by the dealer. When this switch is in the [A (left)], [B (right)] or [Center] position, the feature programmed (by your dealer) to that switch position will be activated. See the next section for details regarding the available features.

r Press the DTMF keys on the telephone keypad

while pressing the PTT switch to send DTMF tones (16-key version only).

r If a Speaker/Microphone is available, remove the

plastic cap and its two mounting screws from the right side of the transceiver, then align the connector of the Speaker/Microphone on the transceiver body; secure the connector pin using the screws supplied with the Speaker/Microphone. Hold the speaker grille up next to your ear while receiving. To transmit, press the PTT switch on the Speaker/Microphone, just as you would on the main transceiver’s body, and speak into the microphone on a normal voice level.

Note: Save the original plastic cap and its mounting screws. They should be reinstalled when not using the Speaker/Microphone.

Operating Manual Reprint

ADVANCED OPERATION

Soft key and TOGGLE switch Functions

The VX-900 includes the [TOP SEL], [SIDE SEL], [

MONITOR], and [LAMP] keys, and the TOGGLE

switch, while the 16-key version additionally provides [A], [B], [C], [D] function keys. The Soft key and TOGGLE switch functions can be customized, via programming by your VERTEX STANDARD dealer, to meet your communications/network requirements. Some features may require the purchase and installation of optional internal accessories. The possible Soft key and TOGGLE switch programming features are illustrated at the right, and their functions are explained on next page. For further details, contact your VERTEX STANDARD dealer. For future reference, check the box next to each function that has been assigned to the Soft key and TOG- GLE switch on your particular radio, and keep it handy.

Functions

None Channel Scan Dual Watch High/Low Power Talk Around TX Save Disable LCD Invert Encryption Disable Follow-Me DW Call/Reset Speed Dial Emergency Group Up Group Down Channel Up Channel Down Monitor Lamp

TOP SEL

SIDE SEL MONITOR LAMP

Functions

None Channel Scan Dual Watch High/Low Power Talk Around TX Save Disable LCD Invert Encryption Disable Lock Follow-Me Scan Group recall Shortcut

Requires FVP-25 DTMF/Encryption Unit

Soft key

[A] [B] [C] [D]

TOGGLE switch (Position

A B

center

£ Group 1 £ Group 2 £ Group 3

)

Requires FVP-25 DTMF/Encryption Unit

Operating Manual Reprint

ADVANCED OPERATION

Description of Operating Functions

Channel Scan

The Scanning feature is used to monitor multiple signals programmed into the transceiver. While scanning, the transceiver will check each channel for the presence of a signal, and will stop on a channel if a signal is present.

One key or switch may be assigned to the Scan function, as follows:

One of the Soft keys may be assigned for Scan

operation; or The TOGGLE switch may have one position as-

signed to the Scan function.

To activate scanning:

Press the assigned Soft key, or set the TOGGLE

switch to the assigned position. The scanner will search the channels, looking for

active ones; it will pause each time it finds a channel on which someone is speaking.

To stop scanning:

Press the assigned Soft key, or set the TOGGLE

switch to a different position. Operation will revert to the channel to which the

CH knob is set.

Note: Your dealer may have programmed your radio to stay on one of the following channels if you press the PTT switch during scanning pause:

Current channel (“Talk Back”)

“Last Busy” channel

“Priority” channel

“Home” channel

“Scan Start” channel

Dual Watch

The Dual Watch feature is similar to the Scan feature, except that only two channels are monitored:

r The current operating channel; and r The “Priority” channel.

To activate Dual Watch:

Press the assigned Soft key, or set the TOGGLE

switch to the assigned position. The scanner will search the two channels; it will

pause each time it finds a channel on which someone is speaking.

To stop Dual Watch:

Press the assigned Soft key, or set the TOGGLE

switch to a different position. Operation will revert to the channel to which the

CH knob is set.

High/Low Power

Press the assigned Soft key or switch the Toggle switch to the assigned position to set the radio’s transmitter to the “Low Power” mode, thus extending battery life. Press the assigned Soft key again or switch the TOGGLE switch to the other Position to return to “High Power” operation when in difficult terrain.

Talk Around

Press the assigned Soft key or switch the TOGGLE switch to the assigned position to activate the Talk Around feature when you are operating on duplex channel systems (separate receive and transmit frequencies, utilizing a “repeater” station). The Talk Around feature allows you to bypass the repeater station and talk directly to a station that is nearby. This feature has no effect when you are operating on “simplex” channels, where the receive and transmit frequencies are already the same.

Note that your dealer may have made provision for “Talk Around” channels by programming “repeater” and “Talk Around” frequencies on two adjacent channels. If so, the key may be used for one of the other Pre-Programmed Functions.

TX Save Disable

Press the assigned Soft key or switch the TOGGLE Switch to the assigned position to disable the Transmit Battery Saver, if you are operating in a location where high power is almost always needed.

The Transmit Battery Saver helps extend battery life by reducing transmit power when a very strong signal from an apparently nearby station is being received. Under some circumstances, though, your hand-held radio may not be heard well at the other end of the communication path, and high power may be necessary at all times.

LCD Invert

Press the assigned Soft key or switch the TOGGLE switch to the assigned position inverts the LCD display to backward-facing readout (the backward display is convenient for viewing when wearing the transceiver on your belt). Press the assigned Soft key again or switch the TOGGLE switch to the other Positionreturn the LCD display to frontward-facing readout.

Encryption Disable

Press the assigned Soft key or switch the TOGGLE switch to the assigned position to turn off the optional voice encryption unit temporarily, for use when an incorrect setting of (or failure in) the encryption system at one end of the communication path has made it im-

Operating Manual Reprint

ADVANCED OPERATION

possible to talk to the other station.

Remember that disabling the encryption will mean that

your transmissions are no longer secure. Return to the

encrypted mode as soon as possible, and do not discuss

any critical or confidential information while in the non-

encrypted mode of operation.

Lock

Switch the TOGGLE switch to lock the top-panel keys;

this can be enabled to prevent radio settings from be-

ing disturbed.

Follow-Me Scan

“Follow-Me” Scan feature checks a User-assigned Pri-

ority Channel regularly as you scan the other chan-

nels. Thus, if only Channels 1, 3, and 5 (of the 8 avail-

able channels) are designated for “Scanning,” the user

may nonetheless assign Channel 2 as the “User-as-

signed” Priority Channel via the “Follow-Me” feature.

To activate “Follow-Me” scanning, first select the chan-

nel you want to designate as the “User-Assigned Pri-

ority Channel” and Switch the TOGGLE switch to

the assigned position. Then turn the CH selector knob

to the “Scanning Start” channel which has been pro-

grammed by your dealer to activate the scanner. When

the scanner stops on an “Active” channel, the User-

assigned Priority Channel will automatically be

checked every few seconds; if activity is found on the

User-assigned Priority Channel, the radio will switch

between it and the Dealer-Assigned Priority Channel,

if any.

Follow-Me DW

To set up a “Dual Watch” frequency pair using the “Fol-

low-Me” feature, select a channel using the CH selector

knob. Now press the assigned Soft key; pressing the as-

signed Soft key locks the current channel as the User-

assigned Priority Channel. Now rotate the CH selector

knob to another channel (not the “Scanning Start” chan-

nel). Your radio will now switch back-and-forth between

the currently-selected channel (shown on the CH selec-

tor knob) and the User-assigned Priority Channel.

During “Follow-Me” scanning (after you have pressed

the key), you can set up the “Dual Watch” feature by

rotating the CH selector knob to another channel. The

radio will then scan back and forth between the origi-

nal User-assigned Priority Channel and the newly-se-

lected channel.

The Priority Channel you have assigned (before press-

ing the key) will be retained in memory until you

change it.

Channel Group Selection

The VX-900 is capable of separating its 512 memory channels into any of 20 Groups. There is no limit as to the number of channels which may be assigned to each Group. The Dealer will have made the Group assignment at the time of channel programming. At the same time, one of the Soft Keys will be assigned as the Channel Group Selection key.

To change Channel Groups, press the assigned soft key to step through the available Groups. Once the desired Group is reached, rotate the CH selector knob to select the desired channel within the selected Group.

You may wish to have the Scanner (described previously) pass through more than one Group during the scanning process (normally, scanning is performed within the current group only). To include the current Group in the scanning loop, press and hold in the assigned Soft key for one second.

To remove a Group from Group Scan, press and hold in the assigned Soft key again for one second.

Multi-Group Scanning is only possible if you are using the “User Scan” list.

The VX-900 has two scanning “lists:” the “Dealer Scan” list and the “User Scan” list. The “Dealer Scan” list is a fixed group of stations which will be included when scanning is activated. The “User Scan” list is a different list, initially arranged by the Dealer, which may be modified by the User (if, for example, you want to delete one or more of these channels from the scanning list).

To edit the User Scan list, press and hold the soft key (assigned to the Group Up/Down function) to delete the current Memory Group from the Scanning. Alternatively, press and hold the “Scan” Soft key for one second to delete the Current Memory channel from the Scanning.

When you delete a Group or channel, “-SKIP-” will appear on the LCD for one second after press ing the Soft key. To restore a particular channel to your scanning list, press and hold in the Soft key again for one second; “-STOP-” will appear on the LCD for one second after pressing the Soft key.

Call/Reset

This feature, if enabled, allows the user to change the 3-digit Page Call code, used to call other similarlyequipped stations. Press the Dealer-assigned soft key, followed by the three digits representing the Page Call code of the station you wish to call. Three tones will

Operating Manual Reprint

ADVANCED OPERATION

be heard after the last key is pressed (the new code will now be transmitted).

The receiver squelch of the other station will be opened, and you can begin communication.

Speed Dial

Your Dealer may have pre-programmed Auto-Dial telephone number memories into your radio.

To dial a number, press the Dealer-assigned Soft key for Speed Dialing, then press the numbered key corresponding to the Auto-Dial memory number list provided by your Dealer. The DTMF tones sent during the dialing sequence will be heard in the speaker.

Emergency

The VX-900 includes an “Emergency” feature which may be useful if you have someone monitoring on the same frequency as your transceiver’s channel. For further details contact your nearest VERTEX STAN- DARD dealer.

ARTS (Auto Range Transpond System)

This system is designed to inform you when you and another ARTS-equipped station are within communication range.

During ARTS operation, your radio automatically transmits for about 1 second every 25 seconds (the interval is programmed by the Dealer) in an attempt to shake hands with the other station.

If you move out of range for more than two minutes, your radio senses that no signal has been received, a ringing beeper will sound, and "OUT OF SERVICE" will scroll on the LCD. If you subsequently move back into range, as soon as the other station transmits, your beeper will sound, and "IN SERVICE" will scroll on the LCD.

DTMF Paging System

This system allows paging and selective calling, using DTMF tone sequences.

When your radio is paged by a station bearing a tone sequence which matches yours, your radio's squelch will open and the alert ringer will sound (unless you have disabled it, as described previously).

The three-digit code of the station which paged you will be displayed on your radio's LCD.

Operating Manual Reprint

ACCESSORIES & OPTIONS

FVP-25 Encryption/DTMF Pager Unit F2D-8 2-Tone Decode Unit F5D-14 5-Tone ENC/DEC Unit FNB-V68LI 7.4 V 1800 mAh Lithium-Ion Battery FNB-V69LI 7.4 V 2400 mAh Lithium-Ion Battery FBA-27 Alkaline Battery Case (6 x AA) VAC-900 Rapid Desktop Charger VAC-6900 6-Unit Multi Charger VCM-1 Mobile Mounting Bracket VTP-50 VX-Trunk Unit MH-50 VH-110 Over the Head, Heavy Duty Headset VH-120 3 wire Mini Lapel Microphone

A7A

Availability of accessories may vary; some accessories are supplied standard per local requirements, others may be unavailable in some regions. Check with your VERTEX STANDARD Dealer for changes to the this list.

Speaker/Microphone (Noise Canceling)

VH-130 Surveillance Kit (Palm Mic/Earpiece) VH-140 DSP VOX Earpiece Microphone VH-150 DSP VOX Headset VH-170 Bone Knocker Headset CE39 Programing Software CT-70 Radio Programing Cable (Requires VPL-1) CT-71 PC Programing Cable CT-72 Radio to Radio Programming Cable LCC-900 Leather Case ATU-6A UHF Antenna, 400 ~ 430 MHz ATU-6C UHF Antenna, 440 ~ 470 MHz ATU-6D UHF Antenna, 450 ~ 485 MHz

Set (Menu) Mode Functions

One or more of the radio’s "Soft Keys" may be enabled for a function associated with the "Set" (Menu) mode. This feature, when activated, allows the user to customize certain performance aspects of the VX-

900. Note that some of these items may also appear as available "Soft Keys," described below.

The operating procedure for the Menu mode is quite simple, requiring only a few easily- remembered actions on the user’s part.

The VX-900 Soft Keys include the [TOP SEL], [SIDE SEL], [MON], and [LAMP] Keys, plus the [A], [B], [C], and [D] keys on the 16-key version. The Soft Key functions can be assigned either as a "Menu" function or an "operating" function at the time of programming.

Basic Menu Mode Operation

1. Press the appropriate Soft Key to activate a Menu

function. The available keys include the [TOP SEL], [SIDE SEL], [MON], and [LAMP] Keys, plus the [A], [B], [C], and [D] keys on the 16-key ver- sion.

2. Rotate the top panel’s CH selector knob to select

the feature you wish to view and/or modify.

3. Press the [TOP SEL] and/or [SIDE SEL] keys to

modify or adjust the current setting of this Menu item ("On" to "Off," etc.)

4. Rotate the CH selector to save the new setting.

5. Press the PTT switch to exit the Set (Menu) mode.

No.2 LIST (Scanning List)

The VX-900 has two scanning "lists:" the "Dealer Scan" list and the "User Scan" list. The "Dealer scan" list is a fixed group of stations which will be included when scanning is activated. The "User Scan" list is a different list, initially arranged by the dealer, which may be changed by the User. This Menu item allows you to select the desired scanning list: "Dealer Scan" or "User Scan". After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to select the Scan List in which you wish to scan ("LIST DLR: Dealer List" or "LIST USR: User List"). Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set (Menu) mode.

No.3 BEEP (Keypad Beeper On/Off)

After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to enable (ON) or disable (OFF) the keypad beep tones. Rotate the CH selector knob to save the new setting, then press the PTT switch

to exit the Set (Menu) mode.

No.4 BELL (CTCSS/DCS/Paging Alert Bell On/Off)

After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to enable (ON) or disable (OFF) the alert bell which sounds when your radio is called using either CTCSS or DCS calling tones. Rotate the CH selector knob to save the new setting, then press

the PTT switch to exit the Set (Menu) mode.

Available Soft Key Menu Functions

No.1 SQL (Squelch Level)

After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to find the point where the background noise is just silenced. This is the point of best receiver sensitivity consistent with quiet monitoring. The scale for the Squelch Level adjustment is 0 ~ 11 and 12 (RSSI SQL), The default value is 8. When the Squelch Level set to "12," this activates the RSSI (Received Signal Strength Indicator) Squelch feature, which allows you to set the squelch so that only signals exceeding a prescribed RX signal input level will open the squelch. The RX signal input level is determined via the Alignment Program SVC39. See page 22 for details regarding the RSSI level setting.

No.5 LGT (TX/BUSY LED On/Off)

After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to enable (ON) or disable (OFF) the LED which serves as the Busy Channel and Transmitter On indicator. Turning this LED off will extend battery life somewhat. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set (Menu) mode.

No.6 LOCK (Keypad, PTT, or Knob Disabling)

In some situations, you may wish to disable the keypad's keys, the CH selector knob, and/or the PTT switch (so as to prevent transmission by unauthorized users of the radio). The LOCK Menu item determines which features will be disabled when the LOCK function is engaged. After selecting this Menu, press the [TOP SEL] or

Set (Menu) Mode Functions

[SIDE SEL] key to select "P" (PTT Lock), "D" (DialKnob-Lock), "K" (Keypad Lock), or various combinations of these. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit

the Set (Menu) mode.

No.7 GROUP (Group Select)

This Menu item allows you to change Channel Groups, in the event that a Soft Key has not been designated for this purpose. After selecting this Menu, press the [TOP SEL] or [SIDE SEL] key to select the Channel Group in which you wish to operate. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set

(Menu) mode.

No.8 SCAN (Scan Mode On/Off)

This Menu item allows you to start the scanner, in the event that a Soft Key has not been designated for this purpose. After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to start ("SCAN ON") or stop ("SCAN OFF") the scanner. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set (Menu) mode.

No.9 DW (Dual Watch On/Off)

This Menu item allows you to activate the Dual Watch feature, in the event that a Soft Key has not been designated for this purpose. After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to enable ("DW ON") or disable ("DW OFF") the Dual Watch feature. Rotate the CH selector knob to save the new setting, then press the

PTT switch to exit the Set (Menu) mode. No.10 TA (Talk Around)

This Menu Item allows you to activate the Talk Around feature, in the event that a Soft Key has not been designated for this purpose. Talk-Around allows direct simplex communications between portables and/or mobiles, utilizing the repeater's downlink frequency. After selecting this Menu item, press the [TOP SEL] or [SIDE SEL] key to enable ("TA ON") or disable ("TA OFF") the Talk Around feature. Rotate the CH selector knob to save the new setting, then press the

PTT switch to exit the Set (Menu) mode.

No.11 ENCR (Encryption)

On channels where scrambling is used, an incorrect setting of (or failure in) the encryption system at one end of the communication path will make it impossible to talk to the other station. To change the current status of encryption on your radio, after selecting this item, press the [TOP SEL] or [SIDE SEL] key to enable (ENCR EN) or disable (ENCR DI) encryption. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set (Menu) mode. Remember that disabling encryption will mean that your transmissions are no longer secure.

Return to the encrypted mode as soon as possible, and do not discuss any critical or confidential information while in the non- encrypted mode of operation.

No.12 AF VR

This Menu item determines the audio volume level when the top panel's VOL knob is set to its fully counterclockwise position (but not into the click stop). This permits the programming of a certain minimum audio output level, in applications where the radio should never go totally silent.

After selecting this item, press the [TOP SEL] or [SIDE SEL] key to select the desired (minimum) volume level. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set (Menu) mode.

No.13 BP VR (Beep VR)

This Menu item determines the beep volume level. After selecting this item, press the [TOP SEL] or

[SIDE SEL] key to select the desired level. Rotate the CH selector knob to save the new setting, then press the PTT switch to exit the Set (Menu) mode.

Cloning

ABCD1328054679#

The VX-900 includes a convenient “Clone” feature, which allows the programming data from one transceiver to be transferred to another VX-900. Here is the procedure for Cloning one radio’s data to another.

1. Turn both transceivers off.

2. Remove the plastic cap and its two mounting

screws from the MIC/SP jack on the right side of the transceiver. Do this for both transceivers.

3. Connect the optional CT-72 cloning cable between the MIC/SP jacks of the two transceivers.

4. Press and hold the PTT and Monitor (just below the PTT) switches while turning the transceiver on. Do this for both transceivers (the order of the switch-on does not matter). “CLONE” will appear on the displays of both transceivers when Clone mode is successfully activated in this step.

5. On the Destination transceiver, press the Moni- tor switch (“LOADING” will appear on the LCD).

6. Press the PTT switch on the Source transceiver; “SENDING” will appear on the Source transceiver, and the data transferred.

7. If there is a problem during the cloning process, “ERR” will be displayed. Check your cable connections and battery voltage, and try again.

8. If the data transfer is successful, the display return to “CLONE”. Turn both transceivers off and disconnect the CT-72. You can then turn the transceivers back on, and begin normal operation.

9. Replace the plastic cap and its two mounting screws.

Optional Cloning Cable CT-72

A B C D

1 32

54 6

7 9

Specifications

GENERAL

Number of Channels: 512 channels Frequency Range: 400 - 430 MHz (AS1), 440 - 470 MHz (CS), 450 - 485 MHz (D), 485 - 512 MHz (F) Channel Spacing: 12.5 / 20 / 25 kHz PLL Steps: 5 / 6.25 kHz Power Supply Voltage: 7.4 VDC ± 20 % Battery Life (5-5-90 duty): w/ FNB-V68LI (1800 mAh): 11 hrs. (14 hrs. w/ saver) @5 W

w/ FNB-V69LI (2400 mAh): 14 hrs. (18 hrs. w/ saver) @5 W

Temperature Range: –22°F to +140°F (–30°C to +60°C) Frequency Stability: EIA: ±2.5 ppm

ETS: ±1.5 kHz

Case Size: 2.3" (w) x 6.1" (H)x 1.3" (D) (59 x 155 x 34 mm) w/ FNB-V68LI Weight (approx.): 0.93 lb. (420 g) w/Antenna, FNB-V68LI and Belt clip Battery: Lithium-Ion 7.4 V 1800 mAh / Lithium-Ion 7.4 V 2400 mAh (optional)

RECEIVER

Circuit Type: Double-conversion Super-heterodyne Sensitivity: EIA12-dB SINAD: 0.25 µV

20 dB Quieting: 0.7 µV (emf) ETS (20 dB SINAD: 0.5 µV (emf)

Adjacent Channel Selectivity: EIA: 75 dB (25 kHz) / 68 dB (12.5 kHz)

ETS: 70 dB (25 kHz) / 60 dB (12.5 kHz)

Intermodulation: EIA: 75 dB (25 kHz) / 65 dB (12.5 kHz)

ETS: 65 dB (25 kHz / 12.5 kHz)

Spurious and Image Rejection: EIA: 75 dB

ETS: 70 dB

Hum & Noise: EIA: 45 dB

ETS: 45 dB

AF Output: 700 mW @ 16 Ohms, 5% THD

TRANSMITTER

Power Output: 5.0 / 2.5 / 1.0 / 0.25 W (selectable) Modulation System: EIA: Direct FM 16K0F3E, 11K0F3E

ETS: 16K0G3E, 8K50G3E

Conducted Spurious Emissions: EIA: 70 dB Below Carrier

ETS: 73 dB Below Carrier

FM Hum & Noise: 45 dB (25 kHz) / 40 dB (12.5 kHz) Audio Distortion (@ 1 kHz): < 3 %

Measuremente per EIA/ETS standards unless noted adove. Specifications subject to change without notice or obligation.

Exploded View & Miscellaneous Parts

RA030720A (Lot. 2~) RA0307200 (Lot. 1~)

KNOB

RA030770B (Lot. 4~) RA030770A (Lot. 1~)

KNOB

RA0296900

HOLDER PLATE

RA0296600

BRACKET

RA0298200

INTER CONNECTOR

G6090144

LCD

RA0317800

DIFFUSER SHEET

RA0298300

INTER CONNECTOR

RA0296500

LIGHT GUIDE

RA0316600 (x2 pcs)

REFLECTOR SHEET A

RA0316700

REFLECTOR SHEET B

RA0317200

LIGHT SHEET A VR UNIT

R6147510

(x2 pcs)

RING NUT

RA0318200 (x2 pcs)

WASHER (B)

RA0297700

LIGHT GUIDE

RA029800A (Lot. 2~) RA0298000 (Lot. 1~)

RUBBER PACKING

LIGHT SHEET B

Non-designated parts are available only as part of a designated assembly.

RA0317300

RA0317000

SHEET (SP)

RA0207800

MIC HOLDER*

RA0297600

EXT CAP

RA0215400

SHEET

RUBBER KNOB

RA0299400

(x2 pcs)

WASHER

BELT CLIP ASS'Y

RA0297500

M4090153 SPEAKER

CP6955001

RA029850B (Lot. 3~) RA029850A (Lot. 1~)

FRONT CASE ASS'Y (16KEY)

RA0297300

RA0306900 (x2 pcs)

COIL SPRING

RA0297000

LATCH PLATE

RA0295300

RUBBER KNOB

MAIN UNIT

SW UNIT

RA0140200

MIC HOLDER

RA0305100

HOLDER (+)

RA0350400 (Lot. 8~)

RA029680A (Lot. 2~)

RA0296800 (Lot. 1~)

RUBBER PACKING

RA0120500

SPRING CONNECTOR

RA0298100

RUBBER HOLDER (+)

DUMMY UNIT

RA0239100

INTER CONNECTOR

RA029720A (Lot. 3~) RA0297200 (Lot. 1~)

TERMINAL PLATE (-)

REF. VXSTD P/N Description Qty.

À U07230107 PAN HEAD SCREW M2X3B #1 1 Á U9900094 TAPTITE SCREW M2X5NI#2 2 Â U44104002 TAPTITE SCREW M2X4NI 7 Ã U9900116 TAPTITE SCREW M2X8NI #2 2 Ä U00119006 PAN HEAD SCREW M2X18AU 1 Å U9900117 TAPTITE SCREW M2X4NI #2 1 Æ U07240202 PAN HEAD SCREW M2X4NI#2 2 Ç U20305007 BINDING HEAD SCREW M3X5B 2 È U02206007 SEMS SCREW SM2.6X6B 2

U20206002 BINDING HEAD SCREW M2.6X6NI 2

U24208002

HOOK

RA029860B (Lot. 3~) RA029860A (Lot. 1~)

FRONT CASE ASS'Y (KEYLESS)

CAUTION

The mic element must be desoldered and removed from the PCB on order to reinstall its protective rubber cover. Therefore, be careful not to remove this cover unless mic element replacement is necessary.

CP6954001 REAR CASE ASS'Y (with/ MIC CONNECTOR,

DOUBLE FACE, SMA CONNECTOR, COVER, SHEET (MICROTEX 5.6X3), RUBBER PACKING )

TAPTITE SCREW M2.6X8NI (Lot. 3~)

Block Diagram

Note:

Circuit Description

Overview

The VX-900 is a UHF FM hand-held transceiver designed to operate in the frequency range of 400 to 512 MHz.

Circuit Configuration by Frequency

The receiver is a double-conversion superheterodyne with a first intermediate frequency (IF) of 44.25 MHz and a second IF of 450 kHz. Incoming signals from the antenna are mixed with the local signal from PLL to produce the first IF of 44.25 MHz.

This is then mixed with the 43.8 MHz second local oscillator (using the 14.6 MHz reference crystal) output to produce the 450 kHz second IF. This is subsequently detected to produce the demodulated signal.

The transmit signal frequency is directly generated by the PLL VCO, and modulated by the signal from the microphone. It is then amplified and sent to the antenna.

Receive Signal Path

Front-end RF Amplifier

Incoming RF from the antenna jack is delivered to the RF Unit and passes through a low-pass filter and high-pass filter consisting of coils L1002, L1003, L1005, L1007, L1001, L1004, L1006, L1008, L1009 and L1011, capacitors C1002, C1005, C1009, C1011,

C1019, C1028, C1003, C1012, C1015, C1018, C1022, C1026, C1030, C1035, C1036, C1039 and C1042, and

antenna switching diode D1016 (HVU131). Signals within the frequency range of the transceiver

are then amplified by Q1012 (BIC702C) and enter a varactor-tuned band-pass filter consisting of coils

L1014, L1015, and L1017, capacitors C1081, C1083, C1094, C1097, C1105, C1106, C1115, C1117, C1121, C1123, C1134, C1139, and C1145, resisters R1079, R1106 and R1124, and diodes D1027, D1028, D1030, D1031, D1032, and D1033 (all HVC350) before de-

livery of the RF signal to the first mixer.

First Mixer

Buffered output from the VCO is amplified by Q1029 (2SC5226-4/5) to provide a pure first local signal between 355.75 and 467 MHz for injection to the first mixer D1037 (GN2011-Q). The 44.25 MHz first mixer product then passes through monolithic crystal fil-

ters XF1001 and XF1002 (MDF0028, ±5.5 kHz BW) to strip away all undesired mixer products.

IF Amplifier

The first IF signal is amplified by Q1044 (2SC52264/5).

The amplified first IF signal is applied to FM IF subsystem IC Q1049 (TA31136FN), which contains the second mixer, second local oscillator, limiter amplifier, noise amplifier, and S-meter amplifier.

A second local signal is generated by Q1051 (2SC4617) using the 14.6 MHz crystal X1002 as a reference, producing a 43.8 MHz signal; this which yields a 450 kHz second IF when the reference signal is mixed with the first IF signal within Q1046.

The second IF then passes through the ceramic filter CF1001 (PBFC450R15D: wide channels), CF1002 (PBFC450R9DR: narrow channels) to strip away all but the desired signal, and is applied to the limiter amplifier in Q1049, which removes amplitude variations in the 450kHz IF, before detection of the speech by the ceramic discriminator CD1001 (CDBC450CX24).

Audio Amplifier

Detected audio from Q1049 is applied to Q1027(AK2345) and the audio low-pass filter, and

then through the volume control (Q1021:M62364FP) to the audio amplifier Q1007 (TDA2822D;external speaker) or Q1011 (TDA2822D;internal speaker), pro- viding up to 0.5 Watt to the optional headphone jack or 16-ohm loudspeaker.

Attention: Audio output is BTL output. Both sides of the audio output are above ground, and this line must not be connected to a speaker line which uses a grounded shield.

Squelch Control

The squelch circuitry consists of a noise amplifier and band-pass filter within Q1049, and noise detector D1058/D1059 (DA221).

When no carrier received, noise at the output of the detector stage in Q1049 is amplified and band-pass filtered by the noise amplifier section of Q1049 and the network between pins 7 and 8, and then rectified by D1058.

Circuit Description

The resulting DC squelch control voltage is passed to pin 19 of the microprocessor Q1050. If no carrier is received, this signal causes pin 6 of Q1052 (BU2090FS) to go low and pin 89 of Q1050 to go high. Pin 6 of Q1052 signals Q1008 (CPH6102), Q1017 (UMC5N) and Q1020 (UMC5N) to disable the supply voltage to audio amplifiers Q1007 and Q1011, while pin 89 makes Q1014 (UMG2N) hold the green (Busy) half of the LED off, when pin 6 of Q1052 is low and pin 89 of Q1052 is high.

Thus, the microprocessor blocks output from the audio amplifier, and silences the receiver while no signal is being received, and also during transmission.

When a carrier appears at the discriminator, noise is removed from the output, causing pin 19 of Q1048 to go low and the microprocessor to blink the busy LED via Q1052.

The microprocessor then checks the DTMF decoder chip on the Optional Unit, the CTCSS and the CDCSS code for DTMF or CTCSS or CDCSS code squelch information, if enabled, respectively. If not transmitting and CTCSS or CDCSS is not activated, or if the received tone or code matches that programmed, the microprocessor stops scanning, if active, and allows audio to pass through the audio amplifier Q1007 and Q1011 (TDA2822D) to the loudspeaker by enabling the supply voltage to it via Q1008, Q1017 and Q1020.

Transmit Signal Path

Microphone Amplifier

Speech input from the microphone is amplified in Q1022 (NJM2902V), is filtered, and is sent to Q1021 (M62364FP) and sent to the Dummy Unit (or Optional Unit). The audio which returned from the Dummy Unit passes through Q1027 (AK2345) to be pre-emphasized.

The processed audio is then mixed with a CTCSS tone generated by microprocessor Q1050 and delivered to D1043 (HVC350) for frequency modulating the PLL carrier up to ±5 kHz from the unmodulated carrier at the transmitting frequency.

If an external microphone is used, PTT switching is controlled by Q1003 (UMZ2N), which signals the microprocessor when the impedance at the microphone jack drops.

If a CDCSS code is enabled for transmission, the code is generated by Q1027 and delivered to D1061 (HVC350) for CDCSS modulation.

If DTMF is enabled for transmission, the tone is generated by the microprocessor Q1050 and applied to the splatter filter (Q1028) in place of speech audio. Also, the tone is amplified for monitoring in the loudspeaker.

Noise Canceling Microphone Circuit

Two signals from separate internal microphones (main and sub) are fed to the positive input (sub) and to the negative input (main) and of Q1022 (NJM2902V). If the same signal level is present at both main and sub, the main signal will be canceled at the output of Pin 1 of Q1022. In other words, noise from nearby sources not directly connected to the transceiver enters the main and sub input at the same signal and, in the absence of (stronger) voice input, is therefore canceled out. When a signal is only input to the main microphone, and there is no signal at the sub microphone, the main signal is passed as-is from Q1022.

Drivers and Final Amplifiers

The modulated signal from the VCO, Q1041 (2SC4227-R34), is buffered by Q1032 (2SC5226-4/

5) and amplified by Q1029 (2SC5226-4/5) and

Q1026 (2SC3356-R25). The low-level transmit sig-

nal is then applied to the Power Module Q1016 (M68732HA-22) for final amplification up to a maximum of 5 Watts of output power.

The transmit signal then passes through the antenna switch D1016 (HVU131), and is low-pass filtered to suppress harmonic spurious radiation before delivery to the antenna.

Automatic Transmit Power Control

RF power output from the final amplifier is sampled by C1020 and C1025, and is rectified by D1021 (RB715F). The resulting DC is fed back through Q1018 (NJM2902V) to the Power Module, providing control of the power output.

The microprocessor selects either "High" or one of three "Low" power levels.

Circuit Description

Transmit Inhibit

When the Transmit PLL is unlocked, pin 18 of PLL chip Q1053 goes to logic "low." The resulting DC "unlock" control voltage is passed to pin 20 of microprocessor Q1050. While the transmit PLL is unlocked, pin 85 of Q1050 remains low, which then turns off the Automatic Power Controller Q1024 (PDTC144EE) and Q1018 (NJM2902V) to disable the supply voltage to the Power Module Q1016, disabling the transmitter.

Spurious Suppression

Generation of spurious products by the transmitter is minimized by the fundamental carrier frequency being equal to final transmitting frequency, modulated directly in the transmit VCO. Additional harmonic suppression is provided by a low-pass filter consisting of L1003, L1005, and L1007 and C1005, C1009, C1011, C1013, C1019, and C1028, resulting in more than 60 dB of harmonic suppression prior to delivery of the signal to the antenna.

PLL Frequency Synthesizer

The PLL frequency synthesizer consists of the VCO,

Q1043 (2SK508-K52:RX) or Q1049 (2SC4227R34:TX); VCO buffers Q1032 (2SC5226-4/5), Q1029

(2SC5225-4/5) and Q1046 (2SC5225-4/5); PLL subsystem IC Q1053 (SA7025DK) and 14.6 MHz reference crystal X1002.

The frequency stability is ±2.5 ppm within the temperature range of -30° to +60°C. The output of the

14.6 MHz reference is applied to pin 8 of the PLL IC. While receiving, VCO Q1043 oscillates between

355.75 and 467.75 MHz according to the transceiver version and the programmed receiving frequency. The VCO generates at 355.75 to 467.75 MHz for providing to the first local signal. In the transmit mode, the VCO generates 400 to 512 MHz.

utilizing a 40 or 50 kHz reference signal which is eighth multiple of the channel step size (5, 6.25 or

7.5 kHz). The input signal from pins 5 and 8 of the PLL IC is divided down to 40 or 50 kHz and compared at the phase comparator. The pulsed output signal of the phase comparator is applied to the charge pump and transformed into a DC signal in the loop filter. The DC signal is applied to the pin 1 of the VCO and locks to keep the VCO frequency constant.

PLL data is delivered from DTA (pin 100), CLK (pin

2) and PSTB (pin 98) of the microprocessor Q1050. The data are applied to the PLL IC when the channel is changed or when transmission switches is changed to reception (and vice versa). A PLL lock condition is always monitored by the pin 20 of Q1050. When the PLL is unlocked, the "UL" line goes low.

Miscellaneous Circuits

Push-To-Talk Transmit Activation

The PTT switch on the microphone is connected to pin 32 of microprocessor

Q1050, so that when the PTT switch is closed, pin 85 of Q1050 goes high. This signals the microprocessor to activate the TX/RX controller Q1004 (UMG2N), which then disables the receiver by interrupting the 5 V supply bus at Q1013 (UN911F) to the front-end, FM IF subsystem IC Q1049, and the receivers VCO circuitry.

At the same time, Q1001 (XP1501) and Q1002 (CPH6102) activate the TX 5V supply line to enable the transmitter.

The output of the VCO is amplified by Q1046, and is routed to pin 5 of the PLL IC. Also the output of the VCO is amplified by the Q1029 and routed to the first local and the drive chain according toinstructions from D1035.

The PLL IC consists of a prescaler, fractional divider, reference divider, phase comparator, and a charge pump. This PLL IC is a fractional-N type synthesizer

Alignment

Introduction

The VX-900 is carefully aligned at the factory for the specified performance across the frequency range specified for each version. Realignment should therefore not be necessary except in the event of a component failure, or when altering the version type. All component replacement and service should be performed only by an authorized VER- TEX STANDARD representative, or the warranty policy may be voided.

The following procedures cover the sometimes critical and tedious adjustments that are not normally required once the transceiver has left the factory. However, if damage occurs and some parts subsequently are placed, realignment may be required. If a sudden problem occurs during normal operation, it is likely due to component failure; realignment should not be done until after the faulty component has been replaced.

We recommend that servicing be performed only by authorized VERTEX STANDARD service techni- cians who are experienced with the circuitry and fully equipped for repair and alignment. Those who do undertake any of the following alignments are cautioned to proceed at their own risk. Problems caused by unauthorized attempts at realignment are not covered by the warranty policy. Also, VERTEX STANDARD reserves the right to change circuits and alignment procedures, in the interest of improved performance, without notifying owners.

Under no circumstances should any alignment be attempted unless the normal function and operation of the transceiver are clearly understood, the cause of the malfunction has been clearly pinpointed and any faulty components replaced, and realignment determined to be absolutely necessary.

Do not attempt to perform only a single step unless it is clearly isolated electrically from all other steps. Have all test equipment ready before beginning, and follow all of the steps in a section in the order presented.

The following test equipment (and thorough familiarity with its correct use) is necessary for complete realignment. Correction of problems caused by mis-

alignment resulting from use of improper test equipment is not covered under the warranty policy. While most steps do not require all of the equipment listed, the interactions of some adjustments may require that more complex adjustments be performed afterwards.

Required Test Equipment

r RF Signal Generator with calibrated output level

at 600 MHz

r Deviation Meter (linear detector) r In-line Wattmeter with 5% accuracy at 600 MHz r 50-Ohm RF Dummy Load with power rating 10W

at 600 MHz

r 16-Ohm AF Dummy Load

(Attention : Audio output is BTL output; do not

short "shield" to ground!)

r Regulated DC Power Supply (standard 7.5V DC,

3A)

r Frequency Counter with 0.2 ppm accuracy at 600

MHz

r AC Voltmeter r DC Voltmeter r UHF Sampling Coupler r IBM PC / compatible Computer with Microsoft

DOS v3.0 or later operating system

r Vertex Standard CT-71 Connection Cable and

SVC39 Alignment program

Alignment Preparation and Precautions

A 50-Ohm RF Dummy Load and in-line wattmeter must be connected to the main antenna jack in all procedures that call for transmission, except where specified otherwise. Correct alignment is not possible with an antenna.

After completing one step, read the following step to determine whether the same test equipment will be required. If not, remove the test equipment (except dummy load and wattmeter, in connected) before proceeding.

Correct alignment requires that the ambient temperature be the same as that of the transceiver and test equipment, and that this temperature be held constant between 20° and 30° C (68 ° ~ 86 ° F). When the transceiver is brought into the shop from hot or cold air, it should be allowed time to come to room temperature before alignment.

+ 46 hidden pages

Vertex Standard VX-900 User Manual

Introduction

Contents

Operating Manual Reprint

CONTROLS & CONNECTORS

LCD ICONS & INDICATORS

BEFORE YOU BEGIN

OPERATION

ADVANCED OPERATION

ACCESSORIES & OPTIONS

Set (Menu) Mode Functions

Basic Menu Mode Operation

Available Soft Key Menu Functions

Cloning

Specifications

GENERAL

RECEIVER

TRANSMITTER

Exploded View & Miscellaneous Parts

Block Diagram

Circuit Description

Overview

Circuit Configuration by Frequency

Receive Signal Path

Front-end RF Amplifier

First Mixer

IF Amplifier

Audio Amplifier

Squelch Control

Transmit Signal Path

Microphone Amplifier

Noise Canceling Microphone Circuit

Drivers and Final Amplifiers

Automatic Transmit Power Control

Transmit Inhibit

Spurious Suppression

PLL Frequency Synthesizer

Miscellaneous Circuits

Push-To-Talk Transmit Activation

Alignment

Introduction

Required Test Equipment

Alignment Preparation and Precautions