VHF Station SE-407
überarbeitet am 11.9.2010
In addition to the U.S. VHF stations SCR-608 bought from war surplus, there
was an strong demand of a VHF vehicular station.
The SE-407 has been in use with the infantry and mechanized troops, it
covers the 34 - 50 MHz frequency range with 161 channels and consists of
the Transceiver / Sendeempfänger TR 83, Auxiliary Receiver / Zusatzempfänger ZE 83 and
teh power supply / Speisegerät SG 83.
Tha transceiver TR 83 is mounted at the left in the mounting frame, it's dimensions are 302 x 260 x 340 mm and it's weight 23,2 kg. In the transmitter section of the modular construction, the signal of the common oscillator operating in the 34 - 50 MHz range is fed through an amplifier and exciter stage to the two final valves in a push-pull arrrangement, the antenna is fed through a variable coupler and antenna tuner.
For the modulation, a small inductance in the oscillator stage get's a variable connection to transmitter mass via a modulation diode, this arrangement does influence the oscillator frequency (frequency modulation).
The incoming signal is amplified and mixed with the receiver oscillator signal to generate a first intermediate frequency of 8 MHz. The signal is mixed to a second low intermediate frequency of 1,6 MHz and the signal is demodulated after having passed the limiter stage.
The power supply generates all necessary voltages for the transceiver and the auxiliary receiver and other modules from the 12 or 24 V DC vehicular power system. The correct voltage must be switched on the power supply, on the auxiliary receiver and with two switches on the mounting frame.
The auxiliary receiver ZE 83 is technically identical to the receiver section of the TR 83,
the cabinet is a bit smaller with 212 x 260 x 340 mm and "only" 21,1 kg.
A core component of the whole transceiver is the so-called "Instantuner", where the oscillator signals for the channels with 100 kHz channel spacing are generated and in which twelve frequencies can be programmed mechanically.
The pre-programmed channels can be recalled from a control set installed at the
tank commander's seat, You can also select whether you want to hear the signal
of the main or the auxiliary receiver or the on-board intercom in the headphones.
From a remote control set, the station can be controlled over field telephone lines.
There is a big number of other acessories: an external speaker LS 83, the typical Swiss Army microtel (like a telephone handset), a headgear with headphones and throat microphone to be used in noisy surroundings and various antenna equipment.
© 15.11.2008 Martin Bösch