User's Guide

Enhanced AM/FM Synthesizer Instruction Manual OS(R/T)-3(A/H) 29 - 935 MHz 3-1
3 SYNTHESIZER ALIGNMENT
3.1 General
OS(R/T)-3(A/H) enhanced synthesizer alignment is simplified by using a Type 84 subrack and
RF extender card/cable of providing receiver or transmitter power and signal interconnection.
Alternately, +9.5 Vdc may be directly connected to a receiver or transmitter module with the
positive connection on pins B6 / Z6 and the negative connection on pins B30 / Z30 / B32 / Z32.
Receiver balanced audio (600 Ω) is available at pins B26 and Z26.
3.2 Repair Note
The OS(R/T)-3(A/H) synthesizer employs a large number of surface mount components.
Removal and/or replacement of surface mount components should never be performed using an
ordinary soldering iron but should only be performed at surface mount rework and repair stations
equipped with Electro Static Dissipative (ESD) protection.
When removing Surface Mount Solder Jumpers, it is recommended that solder wick braid be
used in lieu of vacuum type de-soldering tools to help prevent damage to the printed circuit
boards.
3.3 Recommended Test Equipment
Alignment of the synthesizer requires the following test equipment, or its equivalent:
Power supply - Regulated +9.5 Vdc at 2 A. Phillips PM 2811
Oscilloscope / Multimeter - Fluke 97 Scopemeter
Radio communications test set - Marconi Instruments 2965A
It is recommended that the radio communications test set be referenced to an external high
stability frequency source (WWVH, GPS, Loran C) so that the OS-3A/H internal high stability
local oscillator may be accurately set to within its ±1 ppm frequency tolerance.
3.4 OS(R/T)-3(A/H) Synthesizer Factory Configuration
The OS(R/T)-3(A/H) Synthesizer is factory configured as follows:
• Internal 9.6 MHz reference selected.
• VCO modulation (via audio processor) enabled (OST
TX versions only)