[GreenKeys] AN/FGC-29

[WilliamJ.Neill]

TM 11-2245 dated Aug. 3, 1956 sez that the AN/FGC-29 is:

1.  The terminal equipment for a 16-channel carrier telegraph system 
that provide communication over long range, twin-channel, 
single-sideband radio circuits operating in the high-frequency range.

2.  The carrier telegraph channels are capable of teletypewriter 
operation at a maximum speed of 100 words per minute.

3.  The center frequencies of the carrier telegraph channels are spaced 
170 cycles apart, starting at 425 cycles per second (cps) and continuing 
up to 2,975 cps.

4.  The telegraph channels use frequency-shift carrier signals, with a 
marking signal 42.5 cycles above center frequency and a spacing signal 
42.5 cycles below the center frequency of each channel.

5.  Diversity combining methods are used to overcome the effects of 
radio fading.  Facilities are provided for both 2-channel and 4-channel 
diversity combining, using frequency diversity or space diversity, or 
both.  Selection of 2-channel  or 4-channel diversity combining can be 
made at Telegraph Terminal AN/FGC-29 pr from a remote control location.

6.  Multiplexing equipment is provided to derive two voice-frequency 
(vf) circuits from each of the radio channels.  The radio bandwidth, 
from 200 to 6,000 cps, is divided into two transmission circuits, each 
with a bandwidth from 375 to 3,025 cps.  Four such vf circuits are 
derived from the twin-channel radio and are used to transmit the 
carrier-telegraph signals, or to provide telephone or facsimile service.

7.  Equalizer and amplifier equipment is provided to permit operation of 
Telegraph Terminal AN/FGC-29 over line terminals to remotely-located 
radio terminals.

The illustrative photo in the TM shows the equipment mounted in six 
CY-1119/U racks and there are two separate components:  Telegraph 
Terminal AN/FGT-2 and Telegraph Terminal AN/FGR-3.

This is for someone who has lots of electricity to spare.

William J. Neill
Conroe, Texas

On Monday, February 17, 2003, at 09:04 AM, cswiger wrote:

> Gang -
>
> 	Anybody know of the AN/FGC-29 ?   A google search
> turns up scant little info other than a fair radio manual,
> (telegraph terminal, technical manual) but during a recent
> rtty qso between two real greenkeyers, one recalled the
> an/fgc-29 as the multiplexor that could put 16 75hz tty
> channels on a 3khz voice channel.
>
> I guess they're like modems - you'll need two for a working demo.
>
> --Chuck