DANIELS
ELECTRONICS LTD.
TM
VHF Enhanced Extra Wideband Receiver Instruction Manual IM10-VR3H040-AB
2-7
2.6
Enhanced Synthesizer
The OS-3A/H Synthesizer is a compact, fully shielded and environmentally rugged frequency
synthesis module that is the nucleus of every MT-3 synthesized Receiver and Transmitter radio
module. The OS-3A/H generates a high stability, low distortion radio frequency signal in one of
several frequency bands, including 29 - 50 MHz.
The OS-3A/H utilizes an internal temperature
compensated 9.6 MHz reference to produce a signal stable to ±1 ppm within the temperature
range of -40°C to +60°C. Alternately, the OS-3A/H can be disciplined by an external 9.6 MHz
or 10 MHz reference of higher stability. All synthesizer modules are designed to be easily
removed for programming, calibration and/or repair. The synthesizer circuitry is distributed
between two printed circuit boards (PCBs) which are isolated yet interconnected via photo-logic
optical transceivers that effectively eliminate residual electrical noise between digital and analog
circuitry. Further shielding of the synthesizer’s RF filter circuitry is provided by an internal
shielded enclosure
.