To ensure reliable shortwave communications over whole Switzerland, there was a great demand of high power shortwave transmitters and receivers in the years of World War II. So the decision wase made to re-use shortwave wireless equipment from U.S. bomber aircraft which had made an emergency landing or had been forced to land when entering Swiss air space.

The U.S. Signal Corps SCR-287 equipment has been used on a GMC truck for mobile operation (designation SE-018/m) and in fixed installation in "mountain stations" (designation SE-018/f).
These fixed "mountain stations" have been used to link the airfields of Swiss Air Force, they could be operated manned or remote controlled.

The Transmitter BC-375-E is 58 x 51 x 23 cm wide and has a weight of 23,8 kg, there are six tuning units with 6,5 kg each to go with it. The tuning units cover 1,5-3 MHz (TU-5-B), 3-4,5 MHz (TU-6-B), 4,5-6,2 MHz (TU-7-B), 6,2-7,7 MHz (TU-8-B), 7,7-10 MHz (TU-9-B), 10-12,5 MHz (TU-10-B) and longwaves 200-500 kHz /TU-26-B). To select the desired band, the matching tuning unit has to be inserted in the transmitter cabinet.
The transmitter is powered by a dynamotor PE-73-C, it can be powered from 24 (truck battery) or 28 V DC (aircraft power system).

In the transmitter, a valve VT-4-C (corresponding RCA type 211) acts as oscillator, two more VT-4-C valves as modulator and a fourth VT-4-C as transmitter output tube, it's plate modulated; a VT-25 (RCA 10Y) is used as microphone / AF amplifier.

The equipment on the pictures makes part of a Swiss private collection. I would be very thankful for further information and images of the H-Station.