THOMSON TRC294

Technical data

The TRC294 VHF solid-state receiver was designed by Thomson CSF as a 20-120Mhz monitoring unit.
Its coverage can be extended to 500MHz through the use of the TRC2919 120-500Mhz expander.
It was manufactured at the end of the 70's. It makes use of Advantek (GPD402/GPD403) and Watkins Johnson (A58) MMICs.
Powered by a 6800 with 2Ko of code, it only offers 10 temporary memories (lost on power off) and no other advanced functionnalities.
This TRC family is well engineered and really good in reception of weak signals.
It offers Phi/F3/A3 demodulation with 12/25/50/300Khz bandwidth. Options add A1/A3J+/A3J- with fixed 3Khz bandwith.

This sample seems to came from an early production (NS 103 !).
Some of its cards differ - PCB and/or schematics - from the one detailled in the production manual.
As many of these early 80's receivers, it exhibits a weakness in the 15V power supply design which badly fails had a tantalum capacitor shorts.
The ballast transistor goes short leaving the input supply - 28V - on the 15V path. Tantalums are rated for only 25V...
Here, the ballast transitor, some HF transistors and thirty of these f.....g tantalum were changed before the unit came back to life without any other damage..
Minor changes were made to the front face from the next model, TRC294A.

Pictures

TRC294 - Front
TRC294 - Rear
TRC294 - Up
TRC294 - Under
TRC294 - Display TRC294A- Display
TRC2919 - Front
TRC2919 - Rear
TRC2919 - Up

Cards from the TRC294
GEC101 GEC102
GEC103 GEC103
GEC104 GEC106
GEC109 GEC110
GEC114 GEC115
GEC116 GEC118
GEC119 GEC120
GEC121 GEC130
GEC131
GEC151 GEC151

Cards from the TRC2919
GEH101 GEH102
GEH103 GEH104


Last revision: 2013/07/13