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DESCRIPTION AND MAINTENANCE
851-870 MHz, 100 WATT MASTR II
STATION TRANSMITTER
19D901841G2
TABLE OF CONTENTS
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dissassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alignment Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ILLUSTRATIONS
Figure 1 - Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 2 - Correction Factor Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DESCRIPTION
The 851-870 MHz, 100 Watt MASTR II transmitter is a
crystal controlled, phase modulated transmitter designed for
single frequency operation. The transmitter utilizes both in-
tegrated circuit (ICs) and discrete components and consists
of the following modules:
• Exciter Board; with audio, modulator, amplifier and
multiplier stages.
• Power Amplifier; with or without Antenna Relay.
Figure 1 is a Block Diagram of the 851-870 MHz
MASTR II transmitter, showing the exciter, and the Power
Amplifier assemblies.
The Exciter contains the ± 1 PPM Integrated Circuit Os-
cillator Module (ICOM), audio processor, modulator and
multipliers to provide the station operating frequency.
LBI-31985A
Page
Front Cover
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The PA assembly uses 3 RF amplifier stages to drive a
two transistor power output circuit. Each stage employs
matching networks consisting of discrete components and
strip line technology. The RF output power is fed to the an-
tenna through a circulator containing a low pass filter.
The PA assembly includes a power control module. The
power control module permits adjusting the power output
over a range of 10 to 100 watts. R11 located on the power
control board sets the output level. Three additional adjust-
ments are located on the control board: R2, RS, and R8.
These adjustments are not used in GE MARC applications.
CAUTION
The power adjust must be set for rated output only.
Printed in U.S.A
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Related Manuals for GE Ericsson MASTR II
Summary of Contents for GE Ericsson MASTR II
- Page 1 Three additional adjust- ments are located on the control board: R2, RS, and R8. • Power Amplifier; with or without Antenna Relay. These adjustments are not used in GE MARC applications. Figure 1 is a Block Diagram of the 851-870 MHz CAUTION MASTR II transmitter, showing the exciter, and the Power Amplifier assemblies.
- Page 2 J10 (Green-Hi) and J11 the exciter board out of the radio. sembly. (Black-Lo) on GE Test Set, and connect red Test MAINTENANCE Set plug to the System red metering plug. If not us- Power Amplifier Assembly Removal and...
- Page 3 Set both air variable capacitors to minimum capac- ity (not meshed). Connect the red plug on the GE Test Set to the Sys- tem Board metering jack, and the black plug to the Exciter metering jack. Set the polarity to +, and set the range to the Test 1 position (1 Volt position for 4EX8K12) for all adjustments.
- Page 4 LBI-31985 ALIGNMENT PROCEDURE LBI-31985 ALIGNMENT PROCEDURE METER TUNING METER METER TUNING METER STEP POSITION CONTROL READING PROCEDURE STEP POSITION CONTROL READING PROCEDURE EXCITER 100 WATT PA Terminate the output power J2 with a 50 ohm watt NOTE meter capable of reading 150 watts. When aligning transmitter, proceed as in- structed below.
- Page 5 TROUBLESHOOTING PROCEDURE LBI-31985 STEP 1 - QUICK CHECKS PROBABLE DEFECTIVE STAGE METER POSITION HIGH METER LOW METER ZERO METER READING GE TEST SET READING READING EXCITER Q102, Q103, T101 Q102, Q103, T101 ICOM Q102, Q103, T101, ICOM (PHASE MOD) Q104, T103...
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