Liaison radio transmitter BC 375 E.
It was used in aircrafts like Boeing B17, B 24. during the second world war. Often in conjumction with the receiver BC 348.
It also uses a rotary transformer power supply, which I also own, at a voltage of 28 volts. Frequency bands could be chosen by different, so called tuningboxes. For working on a different frequency band, you had to pull out the tuning box unit in use from the transmitter and insert another one. All provisions were included in the transmitter to match the ouput stage to the end feeded longwire antenna.
It was placed just under the operators table. On the table the receiver BC 348 was positioned.
I use this transmitter often in the 80 meter amateurband on 3705 Khz in phone AM. Output power 100 Watts, anode-screen modulation by a carbon microphone. As a powersupply, I use a homemade mains supply.
My BC 375- E transmitter for 28 volts DC.
Valves transmiiter, left VT 25, on the right four VT 4 C.
The VT 25 is the audio preampliefier. The most left VT 4 is the transmitter VFO and the other VT4’s are the audio power amplifier.Here the front cover of the valves compartment is removed.
The valves are glowing so much, you can almost read your newspaper in the light they are producing. A beautiful view, especially in the dark.