Air Force Voice Broadcast Transmitter S-500 / "Emil"
SO 32/10k
Brown - Boveri, Baden

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Swiss Army Communication Sets
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Army Transmitters
FL 40 S / SE-300
S-500 / "Emil"
S-510 / E-646
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überarbeitet am 30.12.2012

In 1942/3, the Brown Boveri Company at Baden got an order for the construction of a high power voice transmitter to be used by the Swiss central Aircraft Command to direct Air Force flight operations.

This high power transmitter with the BBC designation SO32/10k was called Transmitter "Emil", it was installed at the "Kleine Scheidegg" (near the Jungfrau in the Swiss High Alps) and was powered from the power lines of the Jungfrau Railway.
This transmitter was remote controlled from the Air Force Operations Centers at Dubendorf and Bern over telephone lines, it was used for aircraft flight operations control from 1944 - 1952.

From 1955 to 1986, the same transmitter has been relocated to Fronalpstock and has been used for the Air Raid Warning voice broadcasts of the Air Force Command. The transmitter could be remote controlled from the Air Force operation centers by microwave links.
The "Air Raid Alert Network" used receivers E45, these had automatic muting and selective call capabilities. Because of technical problems, the muting / selective call circuits have been inactivated later. So many messages have been missed at the command posts, because the receiver's volume was usually turned down the whole day long ond the operators missed the scheduled bulletins.
This was the reason why the system has been replaced by a transmitter / receiver system designed by Zellwegerm Uster, with the capability of selective call operation, the S-510 system, which was accepted in 1978 and was introduced in the early eighties to serve with the air raid alert networt of the Swiss Air Force.

Shortwave transmitter,

analog dial,
frequency range 3 - 20 MHz

A1 (CW), A2 (modulated CW telegraphy), A3 (telephony)

pout A1 20 kW; A2, A3 10 kW

horizontal antenna, remote controlled from operations center


Shortly after the beginning of World War II, Brown Boveri, Baden, got the order to construct a 10 kW shortwave transmitter with remote control / remote keying capabilities.
The transmitter "Emil", technical designation SO 32/10k was constructed in 1942/3 and was located in a barrack at Kleine Scheidegg in the Jungfrau mountain and entered service in 1944.

In 1955, the transmitter has been relocated to mountain station Fronalpstock ans has been in use as Air Raid Alert Network transmitter of the Air Force / Anti aircraft troops until 1986.

S-500 Bedienpult
The transmitter S-500 has an analog frequency dial. Sender Emil - Frequenzeinstellung

Nowadays, the legendary transmitter "Emil" is for display at the Air Force Museum Dubendorf.

further information:
Information from the Swiss Air Force Museum Dubendorf, where the equipment is displayed.

© 30.12.2012 Martin Bösch