Aircraft radio Socrat TR-AP-19-A

Socrat Logo
Swiss Army Communication Sets
Synoptic Table
Army Transceivers
Transceivers SE-0xx
(SE-001) / FG I
(SE-002) / FG II
(SE-004) / FG IV
(SE-009) / FG IX
SE-010 / FG X
S-011 / FG XI
SE-013 / SCR-522
SE-015 / STR.9X
SE-016 / Omera
SE-018/m / H-Stat.
SE-020 / Socrat
SE-023 / Collins
SE-051 / Omera
SE-054 / Magnavox
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überarbeitet am 2.1.2013

Together with the helicopter Alouette II built by the French company Sud Aviation, the aircraft VHF radio which came with it made by the French company Socrat was a new part of equipment used by the Swiss Air Force. The Socrat TR-AP-19-A got the military designation SE-020. .


100 - 156 MHz,

Telephony A3, pout 1 W

Receiver section Superhet, IF 9,72 MHz

Selectivity-6/-60 dB
40 / 140 kHz

up to twenty channels crystal controlled or tuneable via VFO, power supply from 27,5 Volts on-board system via a rotary transformer, rod antenna.

The Socrat TR-AP-19-A is a very compact VHF aircraft transceiver built up with valves, is is powered by the helicopter's on board 27,5 V electric system, the high voltages for plate and grids is generated in a rotary transformer.

The set is tuneable in the complete AHF air band range, up to twenty channels can be crystal controlled. The set can also be used as an on-board intercom (position "TELE" of the mode switch.

The VHF radio Socrat / SE-020 was installed in all helicopters Alouette II and probably also i nthe later Alouette III models of the Swiss Air Force, it was in use during the years 1954 - 1976.

I would be very thankful for further information and images.

further information:
Information from the Swiss Air Force Museum Dubendorf, where the equipment is displayed.
d: Socrat ER.9.A in the www.autophon-museum.ch

© 2.1.2013 Martin Bösch