Wavetek 3ST Operation Manual

OPERATION MANUAL

MODEL 3ST

SYSTEM SWEEP TRANSMITTER

This document contains information proprietary to
Wavetek. The information in this document
is not to be used or duplicated in any manner without
the prior approval, in writing, of Wavetek.

WavetekWavetek

Wavetek

WavetekWavetek
CATV Division

5808 Churchman Bypass
Indianapolis, IN 46203-6109
[phone]
[phone]
Fax: [phone]
E-Mail: [e-mail]
Internet: http://www.wavetek.com

11/96 Rev. I,
Manual Part No.
6510-00-0273

WARRANTY

Wavetek warrants that all Products manufactured or procured by Wavetek conform to
Wavetek’s published specifications and are free from defects in materials and workmanship
for a period of one (1) year from the date of delivery to the original Buyer, when used under
normal operating conditions and within the service conditions for which they were designed.
This warranty is not transferrable and does not apply to used or demonstration products.

The obligation of Wavetek arising from a Warranty claim shall be limited to repairing, or at
its option, replacing without charge, any assembly or component (except batteries) which in
Wavetek’s sole opinion proves to be defective within the scope of the Warranty. In the event
Wavetek is not able to modify, repair or replace nonconforming defective parts or components
to a condition as warranted within a reasonable time after receipt thereof, Buyers shall receive
credit in the amount of the original invoiced price of the product.

Wavetek must be notified in writing of the defect or nonconformity within the Warranty
period and the affected Product returned to Wavetek’s factory, designated Service Provider,
or Authorized Service Center within thirty (30) days after discovery of such defect or
nonconformity. Buyer shall prepay shipping charges and insurance for Products returned to
Wavetek or its designated Service Provider for warranty service. Wavetek or its designated
Service Provider shall pay costs for return of Products to Buyer.

Wavetek shall have no responsibility for any defect or damage caused by improper storage,
improper installation, unauthorized modification, misuse, neglect, inadequate maintenance,
accident or for any Product which has been repaired or altered by anyone other than Wavetek
or its authorized representative or not in accordance with instructions furnished by Wavetek.

The Warranty described above is Buyer’s sole and exclusive remedy and no other warranty,
whether written or oral, expressed or implied by statute or course of dealing shall apply.
Wavetek specifically disclaims the implied warranties of merchantability and fitness for a
particular purpose. No statement, representation, agreement, or understanding, oral or
written, made by an agent, distributor, or employee of Wavetek, which is not contained in the
foregoing Warranty will be binding upon Wavetek, unless made in writing and executed by
an authorized representative of Wavetek. Under no circumstances shall Wavetek be liable for
any direct, indirect, special, incidental, or consequential damages, expenses, or losses,
including loss of profits, based on contract, tort, or any other legal theory.

Extended Warranty Programs

Extended warranties and service contracts are available for new and currently owned
equipment for an additional cost. Contact the Customer Service Department (800 851-

1198) for details pertaining to extended warranties and service contracts.

Return Authorization Procedure

The customer MUST obtain a RETURN AUTHORIZATION NUMBER from the
Customer Service Department (800 851-1198) prior to returning any equipment for
warranty or non-warranty repair. Wavetek accepts no liability for any instrument or
subassembly returned to the factory without this number. Any correspondence regarding

returned instruments or subassemblies should be referenced to that number.

Contents

SECTION 1 - GENERAL INFORMATION

1.1 INTRODUCTION ................................................................ 1-1

1.2 SPECIFICATIONS ............................................................. 1-2

1.2.1 Frequency .................................................................... 1-2

1.2.2 Level Measurement ................................................... 1-2

1.2.3 Hum Measurement..................................................... 1-2

1.2.4 Carrier to Noise Measurement .................................. 1-3

1.2.5 Telemetry .................................................................... 1-3

1.2.6 Transmitter.................................................................. 1-4

1.2.7 Spectrum Mode........................................................... 1-4

1.2.8 Intermodulation Distortion ........................................ 1-4

1.2.9 Depth of Modulation .................................................. 1-5

1.2.10 Serial Interface .......................................................... 1-5

1.2.11 General....................................................................... 1-5

1.2.12 Powering .................................................................... 1-5

1.2.13 Standard Accessories................................................. 1-6

1.2.14 Options....................................................................... 1-6

1.2.15 Optional Accessories................................................. 1-6

SECTION 2 - INSTALLATION

2.1 INTRODUCTION ............................................................... 2-1

2.2 UNPACKING AND INSPECTION ................................... 2-1

2.3 INSTALLATION .................................................................. 2-1

2.4 WARRANTY INFORMATION .......................................... 2-2

2.5 POWER REQUIREMENTS ............................................... 2-3

2.6 CABLE SPECIFICATIONS ................................................ 2-3

2.7 TECHNICAL SUPPORT .................................................... 2-5

2.8 WORLDWIDE SALES OFFICES .....................................2-5

SECTION 3 - USER INTERFACE

3.1 INTRODUCTION .............................................................. 3-1

3.2 FRONT-PANEL DESCRIPTION ................................... 3-1

3.2.1 Soft Keys ...................................................................... 3-1

3.2.2 Measurement Mode Selection Keys ......................... 3-2

3.2.3 Support Mode Selection Keys ................................... 3-4

3.2.4 Arrow Keys .................................................................. 3-4

3.2.5 Alpha-Numeric Entry Keys ....................................... 3-5

3.2.6 Printing ........................................................................ 3-6

SECTION 4 - OPERATION - HOW TO USE THE 3ST
TRANSMITTER

4.1 INTRODUCTION .............................................................4-1

4.2 STEALTH SWEEP START-UP PROCEDURE ......... 4-1

4.3 SETUP.................................................................................. 4-4

4.3.1 General Setup............................................................. 4-5

4.3.2 Measurement Setup................................................... 4-8

4.3.3 How To Setup Your Channel Plan .......................... 4-10

4.3.4 How To Edit Channel Parameters .......................... 4-12

4.3.5 Sweep Transmitter ....................................................4-20

4.4 HOW TO PERFORM LEVEL MEASUREMENTS.... 4-22

4.5 HOW TO MEASURE TILT-BALANCING AN

AMPLIFIER ........................................................................4-24

4.6 SCAN MODE ......................................................................4-26

4.7 HOW TO MEASURE C/N ................................................4-30

4.8 HOW TO MEASURE HUM ............................................. 4-32

4.9 MODULATION ................................................................. 4-33

4.10 SPECTRUM ANALYZER MODE ................................ 4-34

4.11 SWEEP MODE ................................................................. 4-39

4.12 FILE.................................................................................... 4-40

4.12.1 How to Store/View/Delete Measurement Files ...4-40

4.13 AUTO .................................................................................4-42

4.13.1 How to Create/Edit/Delete Test Locations ......... 4-42

4.13.2 How to Perform an Auto Test ................................4-45

4.13.3 Viewing/Printing Auto Test Files .......................... 4-53

4.14 STATUS ............................................................................. 4-59

SECTION 5 - REVERSE SWEEP OPTION

5.1 INTRODUCTION .............................................................5-1

5.1.1 Wavetek Stealth Reverse Sweep Concept ..............5-1

5.1.2 Basic Reverse Sweep Procedure .............................. 5-1

5.1.3 Interfacing With Different Network Architectures 5-2

5.2 HOW TO SETUP FOR REVERSE SWEEPING ......... 5-5

5.2.1 Enable or Disable Reverse Sweep ........................... 5-5

5.2.2 Select the Frequency of the Reverse Telemetry

Carrier .........................................................................5-6

5.2.3 Access Reverse Sweep Plans .................................... 5-6

5.2.4 Selecting a Reverse Sweep Plan .............................. 5-6

5.2.5 Creating a New Reverse Sweep Plan ...................... 5-7

5.2.6 Editing a Reverse Sweep Plan ................................. 5-10

APPENDIX A: STATUS INDICATORS ............................... A-1

APPENDIX B: USER MESSAGES ......................................... B-1

MODEL 3ST

SECTION 1 GENERAL INFORMATION

1.1 INTRODUCTION

The Wavetek Sweep System Transmitter performs essential cable TV
system preventive maintenance tests with accuracy and ease. Signal
levels, hum, C/N, and frequency response can be quickly tested
without subscriber interference.

The Sweep System is made up of two components; the Sweep System
Receiver 3SR, and Sweep System Transmitter 3ST. The contents of
this manual will describe the care and operation of the Sweep System
Transmitter 3ST, including Reverse Sweep operation.

Sweep response is tested by injecting a low level signal in vacant
spectrum areas, and monitoring cable system carrier levels in occupied
spectrum areas. In addition to generating the sweep test signal, the
Transmitter 3ST continuously monitors the system carriers. The 3ST
sends headend level readings to the 3SR Receiver with every sweep
update. In this way, any headend level changes are compensated by
the receiver to maintain the utmost measurement accuracy.

Sweep response measurements won't be affected by signal levels
changing in the headend. The Transmitter 3ST has all of the mea­surement capability of the 3SR Receiver, so the Headend Technician
can keep an eye on headend levels.

With the Reverse Sweep option, a transmitter is built into the hand­held sweep receiver. The headend sweep transmitter (3ST) is set up
to receive the reverse sweep sent from the field. When a reverse
sweep is activated from a field test point, the headend transmitter
receives the telemetry signal that indicates which receiver is sending
the sweep. The headend transmitter measures the sweep, and sends
the results, along with the serial number of the sending receiver via its
telemetry signal to the field. The field receiver with the tagged serial
number then displays the sweep response as measured in the headend
on its LCD.

1-1

The 3ST Transmitter is a full-featured signal analysis meter, with a
complete spectrum display and an analog representation of single
channel measurement data. When tuned to a specific channel, a
comprehensive set of information is provided: tuned channel, video
frequency and level, audio frequency and level, the difference
between video and audio carrier levels.

The 3ST Transmitter is a standard 19" rack mount unit, that weighs
approximately fifteen pounds. Its 320 X 240 dot matrix LCD shows
measurement data in both graphical and numerical form.

1.2 SPECIFICATIONS

1.2.1 Frequency

Range: 5 to 1,000 MHz

Accuracy: + 10 ppm at 25°C; + 10 ppm drift over

temp.; + 3 ppm/year aging

Resolution Bandwidths: 30, 280 kHz (30 kHz for CSO)/CTB only)

Tuning Resolution: 10 kHz

Sweep Resolution: 250 kHz maximum

1.2.2 Level Measurement

Range: -40 to +60 dBmV

Resolution: 0.1 dB

Accuracy: + 1.0 dB from 0 to + 40°C (typical),

(relative to 25°C)

1.2.3 Hum Measurement

(carrier > 0 dBmV) Non-scrambled channels only

Range: 0 to 10%

1-2

Resolution: <0.2%

Accuracy: +0.7%

1.2.4 Carrier to Noise Measurement

Non-scrambled channels only. No preselection required for 78
channels at +10 dBmV input level.

Carrier to Noise Ratio

Depth of Measurement Charact eristics

60

Out of Measurement Range

50

40

30

20

Carrier to Noise Range

10

0

-10 0 10 14 24

+3.0 dB Accuracy

+2.0 dB Accuracy

Video Carri er Level (dBmV)

*Specified results with the measurement offset within 2 to 3 MHz
range above the video carrier.”

*

Resolution: 0.5 dB

Range 52 dB maximum

1.2.5 Telemetry

Frequency: User defined, 5 to 1,000 MHz

Modulation: FSK, 100 kHz deviation

Spectrum Required: »1 MHz recommended

1-3

1.2.6 Transmitter

Frequency Range: 5 to 1,000 MHz

Level Range: +20 to +50 dBmV

(1)

; settable in 2 dB

increments

Spectral Purity: Hars -30 dBc; Spurs -35 dBc

1.2.7 Spectrum Mode

Spans: 3, 5, 10, 20, and 50 MHz (0.3, 0.5, 1, 2, and

5 MHz/div)

Sweep Rates: 2 seconds (50 & 5 MHz)

Display Scaling
and Range: 0.5, 1, 2, 5, and 10 dB/division; 6 vertical

divisions

Spurious Free
Dynamic Range: 60 dB (typical specifications)

1.2.8 Intermodulation Distortion

CSO / CTB Characteristics

60

Out of Measurement Range

50

40

30

preselection)

20

Depth of Measurement (dB)

10

(without preamplification / with

0

-20 -10 0 10 20 30

+3.0 dB Accuracy

+2.5 dB Accuracy

Video Signal Level (dBmV)

*

1-4

*Typical Specifications

Range: 60 dB maximum

Resolution: 1 dB

1.2.9 Depth of Modulation

Assumes presence of white reference on any VITS line. Non­scrambled channels only.

Range: 80 to 100%

Resolution: <0.5% at 85%

1.2.10 Serial Interface

Serial, RS232; Epson, IBM Printers

1.2.11 General

Log Linearity: +0.5 dB (typical)

Flatness: +0.5 dB @ 25 °C, @ 20 dBmV

Dimensions: Transmitter 3ST: 48.3 cm (W) x

13.3 cm (H) x 35.6 cm (D), 19" (W) x 5.25"
(H) x 14" (D)

Weight: Transmitter 3ST: 6.8 kg (15 lbs.)

Operating
Temperature Range: 0 to +50°C; 32 to 122°F

1.2.12 Powering

Frequency 47 to 63 Hz ~ 100 VA

Input Current: 1.2A @ 100 VAC.

0.5A @ 265 VAC.

1-5

Fuse 1.25 A, 250V 5X20mm SLO-BLO (2

required)

1.2.13 Standard Accessories

Line Cord
Channel Plan Transfer Cable
Operations Manual

1.2.14 Options

16/64 QAM Digital Carrier Power Measurement - Enables Stealth to
perform accurate level measurements on digital carriers.

1.2.15 Optional Accessories

1010-00-0342 Citizen PN60 (thermal fusion) Printer
1019-00-0457 Optional Battery for PN60 Printer
3010-59-0009 Citizen PN60 Printer Ribbons (2) (included with

printer)
1217-50-0159 Citizen PN60 Printer Cable (included with printer)
4010-00-0105 Charger/Adapter 120VAC to 18VDC
1019-00-0437 Charger/Adapter 220VAC to 18 VDC
SBC-1 Charger for one spare Stealth Battery Cartridge
SBC-6 Charger for up to six spare Stealth Battery

Cartridges
1217-50-0151 Stealth Serial Printer Cable
PP-75 Precision Preselector for Carrier-To-Noise and

Intermodulation Distortion Testing (55 to 440 MHz)
PP-55-110 Tunable Precision Preselector (55 to 110 MHz)
PP-110-220 Tunable Precision Preselector (110 to 220 MHz)
PP-220-440 Tunable Precision Preselector (220 to 440 MHz)
PP-440-880 Tunable Precision Preselector (440 to 880 MHz)
7201 Tunable Precision Preselector (31 to 62 MHz)
7202 Tunable Precision Preselector (62 to 125 MHz)
7203 Tunable Precision Preselector (125 to 250 MHz)
7204 Tunable Precision Preselector (250 to 500 MHz)

1-6

(1)

Specification Change - The transmitter output is being changed
from +10 to +40 dBmV to +20 to +50 dBmV. To determine which
transmitter output range is available on your unit, access the Status
screen by pressing the FCN key followed by the status second
function key. If "Enhanced Output" is displayed in the options box,
the transmitter output range is +20 to +50 dBmV.

1-7

SECTION 2 INSTALLATION

2.1 INTRODUCTION

This section provides information on how to install the 3ST Transmit­ter.

2.2 UNPACKING AND INSPECTION

The instrument was inspected, and given final operational and quality
control tests prior to being carefully packaged for shipment. The unit
should operate in accordance with the specifications listed in this
manual.

When unpacking the instrument, inspect the shipping container and
instrument for shipping damage. If the container is damaged, phone
Wavetek immediately. Save the shipping carton and packing materials
for possible future use.

FOR CUSTOMER SERVICE call: WAVETEK: [phone],
International Customers, contact your local Wavetek Representative.

2.3 INSTALLATION

Proper installation of the Transmitter is essential to correct operation
of the system. The transmitter is typically installed in a headend rack.
There are two different options for setting up the system. One entails
inserting the sweep at a standard combining network input, with a
directional coupler (test point) at the output of the combining net­work.

Alternately, a directional coupler may be used to insert the sweep at
the output of the combiner. A directional coupler is used to sample
system signals in the headend, and an additional directional coupler is
used to inject the sweep (see figure). The sampling directional
coupler (DC a) may be of any value (dB), but higher values are
typically chosen to limit insertion loss. The sweep insertion direc­tional coupler (DC b) tap loss must be taken into account when setting
the insertion level of the transmitted sweep signal.

2-1

The transmitter output level is variable from +20 to +50

s

(1)

dBmV in 2
dB increments. The output level will be attenuated by the tap value
of the directional coupler. For example, if a sweep signal level of
+16 dBmV is desired on the system and the output of the 3ST
Transmitter is set to +36 dBmV, a directional coupler value of 20 dB
may be used, or the combination of a lower value directional coupler
and an attenuator pad.

DC aDC b

Combining

Sy

Network

INOUT

Stealth Transmitter

IN

Stealth
Receiver

An alternate method would be to insert the 3ST Transmitter output
at one of the combining network inputs, and connect the (transmit­ter) reference input to the headend amplifier input test point. This
method eliminates the need to add directional couplers at the
combiner output.

For detailed setup information, see "Stealth Sweep Start-up Proce­dure", page 4-1.

2.4 WARRANTY INFORMATION

The Sweep System Transmitter 3ST is covered by a one year parts
and labor warranty (for details, see "Warranty", opposite Table of
Contents).

2-2

2.5 POWER REQUIREMENTS

The Sweep System Transmitter 3ST operates on 90-265 VAC, 57-63
Hz single phase input power source.

2.6 CABLE SPECIFICATIONS

There are two cables associated with the operation of the 3ST
Transmitter; Stealth to Stealth, and a Serial Printer cable. The
following information describes each of the associated cables.

Stealth to Stealth

The Stealth to Stealth cable, (1217-50-0149) provided with each 3ST
Transmitter, is used for communications between Stealth units and
for downloading sweep files to a PC.

Rx

Tx

DTR

GND

DSR
RTS
CTS

RI

Tx
Rx
DTR
GND
DSR
CTS
RTS
RI

2-3

Serial Printer Cable

The Serial Printer Cable, (1217-50-0151) can be used to print data
directly from the 3ST Transmitter.

Tx
Rx

GND

DTR

Rx
Tx
DTR
GND
DSR
CTS

2-4

2.7 TECHNICAL SUPPORT

Although we've worked hard to make the 3ST as easy-to-use as
possible, the wide range of network architectures available today can
make proper configuration a difficult task. If you have a problem
using your unit you can contact Wavetek's Technical Support for
help. You can reach Wavetek's Technical Support, Monday through
Friday between 8 am and 5 PM at [phone]. Wavetek also
maintains a support forum on the Internet. You can leave messages
and a Support Specialist will get back to you at Internet address:
[e-mail].

If you received your Stealth unit and found it to be damaged or
incomplete in any way, phone Wavetek immediately. Save the
shipping carton and packing material in the event that you have to
return it.

FOR CUSTOMER SERVICE call: WAVETEK [phone],
International Customers, contact your local Wavetek Representative.

The above numbers can also be accessed on your unit by pressing the
FCN key followed by the help key.

2.8 Worldwide Sales Offices

Austria (Vienna) Hong Kong
Tel: [phone] Tel: [phone]
Fax: [phone] Fax: [phone]

China (Beijing) Japan (Tokyo)
Tel: [phone] Tel: [phone]
Fax: [phone] Fax: [phone]

France (Paris) Singapore
Tel: [phone] Tel: [phone]
Fax: [phone] Fax: [phone]

Germany (Munich) United Kingdom (Norwich)
Tel: [phone] Tel: [phone]
Fax: [phone] Fax: [phone]

2-5

(1)

Specification Change - The transmitter output is being changed
from +10 to +40 dBmV to +20 to +50 dBmV. To determine which
transmitter output range is available on your unit, access the Status
screen by pressing the FCN key followed by the status second
function key. If "Enhanced Output" is displayed in the options box,
the transmitter output range is +20 to +50 dBmV.

2-6

SECTION 3 USER INTERFACE

3.1 INTRODUCTION

This section will help you become familiar with the front-panel
controls of the Model 3ST Transmitter. Included are descriptions of
the front-panel and notes on the use of features.

3.2 FRONT-PANEL DESCRIPTION

The hardware portion of the user interface consists of a 320x240 dot
matrix LCD and a 40-key keypad. The keypad includes:

• eight Soft keys

• eight Measurement Mode selection keys

• four Support Mode selection keys

• four Arrow keys

• sixteen Numeric Entry keys

3.2.1 Soft Keys

There are a total of eight vertically oriented soft keys, four on either
side of the display. The function of each soft key changes depending
on the particular operation being performed. The function is indi­cated on the display next to the associated soft key. Soft keys are not
always active. When a soft key is inactive, it’s indicator is either
dimmed (grayed) or does not appear at all.

3-1

3.2.2 Measurement Mode Selection Keys

Measurement modes are chosen by pressing the appropriate Mea­surement Mode Selection key. There is a key for each of the eight
major measurement functions. These keys are located directly below
the display.

LEVEL: Signal level measurements on individual channels are made

by entering a specific channel number and pressing the
channel key. Measurements can also be made by selecting
the carrier with a marker in the Scan mode and pressing the
Level key.

TILT: The Tilt mode simplifies the balancing of pilot levels by

displaying a bar graph with a representation of up to nine
different user selected video carrier levels.

3-2

SCAN: Use the Scan mode to get a good look at absolute carrier

levels. In this mode a bar graph showing all carrier levels is
displayed.

SWEEP:

NOTE: Telemetry occurs only while the unit is in Sweep mode.

C/N: Measures the C/N (carrier to noise) ratio of the tuned

HUM: Measures the hum modulation of the tuned channel, will

MOD: Allows the user to listen to the modulation of the tuned

SPECT: Provides a Spectrum Analyzer display, and CSO/CTB

This mode injects a low level signal in vacant spectrum

areas, and transmits telemetry to any 3SR Receivers that
are connected to the system. Cable system carrier levels in
occupied spectrum areas are monitored and displayed in bar
graph format.

Selecting another mode will result in a loss of telemetry to
any Receivers connected to the system.

channel or frequency will be displayed.

display in either % or dB as selected by the operator.

channel of frequency and measure Depth of Modulation of a
video carrier.

measurements.

3-3

3.2.3 Support Mode Selection Keys

Support modes are accessed using the Support Mode Selection keys.
There is a key for each of the four support functions. These keys are
located to the right of the display.

File: Allows the user to access measurement files.

Auto: This function provides automated FCC 24 hour testing

capabilities.

Setup: The setup functions are used to set or adjust the operating

parameters of the unit.

Print: Allows the user to print the current measurement screen.

3.2.4 Arrow Keys

The four Arrow keys are used for various purposes. There functions
are described in the individual sections for each operating mode.
These keys are located to the right of the Support Mode Selection
keys.

3-4

3.2.5 Alpha-Numeric Entry Keys

The Alpha-Numeric keys are used to enter data as needed during the
operation of the unit. There are three indicators associated with
keypad entry. These indicators appear in the title bar to the left of
the time. The three are as follows:

A

B

- alpha entry mode

C

1

23 - numeric entry mode

- multiple choice mode

3-5

Alpha Entry Mode

Most numeric keys have alphabetic characters printed on them.
These characters can be accessed when the alpha entry indicator
appears in the title bar. In the alpha entry mode, a cursor appears
below the active position. Repeated pressing of an alphanumeric key
sequences through the values printed on the key. Once the desired
character is selected, the cursor is moved to the next position using
the LEFT or RIGHT arrow keys. Special characters are available
using the UP and DOWN arrow keys.

Alpha entry must be terminated by pressing the ENTER key.

Numeric Entry Mode

In the numeric entry mode, only the numerals 0 through 9 and the
decimal point can be entered. When negative values are allowed, the
FCN, +/- key sequence toggles between positive and negative entry.
The numeric value may also be incremented and decremented using
the UP and DOWN arrow keys.

Numeric entry must be terminated by pressing the ENTER key.

Multiple Choice Mode

This mode allows you to sequence through a series of choices which
appear in the edit box.

3.2.6 Printing

Any measurement mode screen can be printed directly. Press the
Print key to print the current measurement screen. To print a
measurement file, simply view the file and print it as you would a
current measurement screen.

3-6

SECTION 4 OPERATION - HOW TO USE THE 3ST
TRANSMITTER

4.1 INTRODUCTION

This section provides detailed operation of the 3ST Transmitter.
Included are detailed descriptions of the various displays of the
selected modes of operation.

4.2 STEALTH SWEEP START-UP PROCEDURE

The Model 3ST Transmitter is quite flexible with regard to sweep
insertion, in that the sweep level relative to the other carriers is not
extremely critical. A key principle to keep in mind is that the trans­mitter measures the levels of the video and audio carriers simulta­neously to the receiver. It also measures its own injected sweep
carrier. In order to do this, the sweep must be injected prior to the tap
which samples the system signal for the transmitter's measurements
(see diagram below).

Combining

Network

Stealth Transmitter

DC aDC b

System

INOUT

IN

Stealth
Receiver

Sweep insertion is prior to sampling of system levels by 3ST Transmitter

The Model 3ST's output may be injected as shown above, using a
directional coupler at the output of the combining network, or it may
even be injected at an input to the combining network. With an
output level set such that the sweep is 15 dB below video carrier level,
good response measurements can be made without interference to
subscriber TV pictures.

4-1

We recommend that the telemetry be set at 10 dB below the video
carrier level.

Any response irregularities caused by the combining network will be
eliminated in the normalization process.

After the transmitter is properly connected, the next step is to build a
channel plan. This channel plan will designate which channels are
active in the system, which channels are scrambled, and which
channels are inactive and therefore can be converted to sweep
injection points. The channel plan can be edited to indicate which
channels are to be tested in the Tilt mode, and to label the channels
with the programming content or call letters of the broadcaster.

The following procedure describes the steps to prepare the transmit­ter for sweeping.

Building A Channel Plan

1. To build a channel plan, first enter the setup mode by pressing the

SETUP key.

2. Press the Channel Plan soft key, and cursor down the menu to

Build Channel Plan.

3. Press the ENTER key, and you will be prompted at the first step to

name the channel plan to be built. The name should be a logical
one that will be easy to remember. The location of the headend is
usually a good name for the channel plan. When the name is typed
in, press the ENTER key.

4. The next step is to choose a channel plan from the built-in list that

most closely resembles the plan of your system. Typically your
system channel plan will be a subset of the built-in plan. Cursor
down to the appropriate channel plan and press the ENTER key or
the OK soft key.

5. You will then be prompted to enter the highest frequency that you

would like to scan. Type in the frequency and press the ENTER
key followed by the OK soft key. The unit will then commence a
scan for the presence of channels. After the scan is done, this
phase of the channel plan building process is complete. Press the
Exit soft key to return to the Channel Plan menu.

4-2

Editing A Channel Plan

The next step is to edit the channel plan to characterize it for your
particular system. Cursor down to Edit Channel Parameters and press
ENTER. A listing of all the channels within the frequency range
designated in the Build Channel Plan phase will appear on the
screen. Notice that there are columns for enabled, channel type,
channel number, label, frequency (video carrier), sweep, tilt, and,
scrambled.

Each of these features for each channel may be edited by cursoring to
the channel to be edited and pressing the Edit soft key.

Check the listed channels to ensure that channels that you know are
not video are not listed as video channels. If during the Build Chan­nel Plan phase the receiver detects a signal at a video carrier fre­quency it assumes it is a video channel. Some FM carriers may
happen to fall at video carrier frequencies for channels 95-97. Be sure
these channels are properly designated as video or single carriers. FM
signals may be entered as channels, but must be designated as Single
Carriers.

At this time be sure to edit each scrambled channel to ensure that it
is designated appropriately. A special algorithm is used to ensure that
the peak of these signals is measured.

At this time you may also wish to designate tilt channels, and label
the channels with call letters, but this is not essential to begin the
sweep process.

You may have noticed that the channel plan list included some
channels that were not marked "Enabled". These channels can be
converted automatically to sweep points using the Build Sweep
Points selection from the channel plan menu. Before doing this,
make sure that these "disabled" channels do not encompass an area of
digital or other signals that you want to avoid sweeping. If they do,
simply edit these particular channels and toggle to "No" on the
Sweep Channel selection. When this is completed, select Build
Sweep Points from the Channel Plan menu. Sweep points can
convert each disabled channel into 1, 2 or 3 sweep points.

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The next step is to test the sweep by connecting the Model 3SR
receiver to a test point and pressing the SWEEP key (Ensure the
3ST Transmitter is also in the Sweep mode). After telemetry is
found, the receiver will begin sweeping. If telemetry is not found
make sure the 3ST Transmitter and the 3SR Receiver are configured
for the same telemetry frequency. Check to ensure the level of the
sweep, seen in empty spectrum areas, is 15 dB below video carrier
level. At first there will be no references for the normalized compari­son.

Storing A Sweep Reference

Wait until the "wait" indicator on the top of the sweep display
disappears, then press the FILE key. Next press the Sweep Refer-
ences soft key. The first step is to enter the name of the reference.

This can be any name that makes sense to you, and identifies the
location of the reference measurement.

After the reference is stored, press the SWEEP key, and the sweep
will be compared to the reference you just stored. The response
should be relatively smooth, the D marker should indicate < 1.0 dB.
If you have a higher number than this, or if the number is fluctuating
above this, you may need to do some channel plan editing to identify
scrambled channels, or to properly identify active/inactive channels
of FM or data carriers.

4.3 SETUP

There are four setup modes for the 3ST Transmitter; General,
Measurements, Channel Plan, and Sweep Transmitter. General setup
allows the operator to configure general aspects of the unit (not
specifically related to measurements) for personal taste. Measure­ments setup permits the operator to setup certain parameters that
apply to specific measurements. Channel Plan setup allows the
operator to configure channel tuning to match the specific character­istics of a particular cable system. Sweep Transmitter setup lets the
operator setup sweep transmission parameters.

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4.3.1 General Setup

Use the Up and Down soft keys to scroll to additional setup items.
When lists are being displayed, the up arrow soft key dims when the
first item in the list is reached and the down arrow soft key dims
upon reaching the last item.

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Operator Name

Allows the user to enter the operators name. The name will appear in
the header section of the Auto Test report.

Contrast Level

Adjusts the contrast level of the LCD for optimum viewing by the
operator. The level is varied on a scale from 1-15. Use the UP and
DOWN arrow keys to adjust the contrast. Contrast Level

Adjusts the contrast level of the LCD for optimum viewing by the
operator. The level is varied on a scale from 1-15. Use the UP and

DOWN arrow keys to adjust the contrast.

Backlight Time-out Period

An additional feature is an automatic Backlight Time-out. The time
out period is programmable to; always off, 5 sec, 10 sec, or always on.
Use the UP and DOWN arrow keys to set the time-out period. The
Backlight can be manually turned on/off at any time by pressing the

Function key followed by the Light second function key.

Time

Use the numeric entry keys to enter the time in the HH:MM:SS
format (24 hour).

Date

Use the numeric entry keys to enter the date. The date will be
displayed in the format chosen in the Date Format setup menu.

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