The Frederick Electronics Model 1203 FSK demodulator is designed to provide optimum detection of frequency shift keying signals with shifts between 0 and 1000 cps, and with keying rates up to 74.2 baud. This 1 Rack unit (1 3/4") high demodulator was made in the golden age of electronics, i.e. it is solid state construction usingdiscrete components so is easy to maintain. May be the most advanced RTTY demodulator made for single channel signals. It will work with Mark only, Space only or both.
There is a front panel tuning meter and in addition there are Mark and Space lights to aid in tuning in a signal.
Made utilizing US Patent 2,999,925 "Variable Decision Threshold Computer" Sep. 12, 1961 assigned to Page communications Engineers Class # 375/317 In manual paragraph 4.2.8 Decision Threshold Computer there is a description of how the threshold between Mark and Space is dynamically adjusted for optimum signal/noise ratio.
It has an attached 3 wire line cord and wires for the 600 Ohm balanced audio input from a receiver and a jack for a current loop connection to a RTTY (RAT) machine.
The 1966 partial reprint manual contains the following chapters:
- Theory of Operation
- Checkout and Alignment
- Schematic Diagrams
- Assembly Diagrams
The CV-89A/URA-8A is a Military tube type FSK converter with a CRT type tuning indicator.Back to Brooke's Products for Sale, Military Information, PRC-68 Family of Squad Radios, U229 Audio Accessories, Audio Connectors, Electronics, Home page
The CV-483/URA-17 is a solid state FSK converter with a CRT type tuning indicator.
The MD-1142 (BR Communications 6029C) Time Deversity Modem
The Frederick 600A is a rack mount modular digital communication test set.
Digitech also made a modular rack mount Digital Data Generator test set
This is the time this page has been accessed since 24 April 2003.
Back to Brooke's Products for Sale, Military Information, Home page
This is the time this page has been accessed since since 24 April 2003.