Inhaltsverzeichnis
AN/VRC-46
AN/VRC-46; basic set of the AN/VRC-12 family, Swiss Army designation SE-412; manufactured by Associated Industries.
In the United States, the VRC-12/VRC-46 VHF communication system was introduced in the mid-1960s. The RT-524A was designed for direct operation and the similarly sized RT-246, with ten memory channels, was designed to be installed in equipment bays of tanks or similar vehicles, with the possibility of remote control.
At the end of the 1960s, two U.S.-made VHF radio sets were also introduced in Switzerland when the American M113 armoured personnel carrier was acquired: the PRC-77 SE-227 and the VRC-46 or SE-412, which was used in vehicles.
Technical data
- Frequency range: 30-52.95 and 53-75.95 MHz, 920 channels with a channel spacing of 50 kHz
- Transmitter power F3 1-3 W (low power) / 35 W (high power)
Power supply
- Mains operation: only withseparate mains power supply
- Batteries: 22 - 30 V DC, usualy from onboard power system (vehicle battery)
Dimensions
- 391 x 171 x 334 mm, 23.15 kg
Accessories
- The standard antenna used in Switzerland was the AT-912/VRC rod antenna with the MX 2799/VRC automatic antenna tuner.
- Alternatively, a remote-controlled ground plane antenna, the FA-227/412, could be used. This antenna has a 2.45 m high rod on a 4 m high mast. The long distance antenna material was stored in a canvas bag measuring 110 x 200 x 12 mm and weighing 9.1 kg.
- A on-board communications amplifier was installed in the vehicles, which served as an on-board communication system.
- At the monitor boxes in the vehicle, each crew member could select which programme (receiver A, B or C or intercom traffic) was to be heard in the headphones.
- The C-2299/VRC relay switching device could be used to connect two transceivers to form a relay station.
- A Mikrotel MT H-189 or the noise headset with headphones, throat microphone and transmit/receive switch was used by the operators.
- The FBA SE-227/412 remote control equipment is used to remotely control the SE-412, for example from a protected shelter. The local control unit, which is connected to the SE-412 AUDIO input, and the remote control unit, are connected to a standard two-wire field telephone line.
Operation
The VHF radio RT-524A covers the military VHF range in two bands (30 - 52.95 and 53 - 75.95 MHz) with 50 kHz channel spacing, the transmission power can be switched between POWER LOW (1-3 W, range of approx. 5 km) and HIGH (approx. 35 W, range 20-30 km) in FM telephony mode.
On the front panel of the transceiver, there is a CALL lamp in the upper left corner, which signals an incoming radio message when the squelch is activated. Next to it is the band switch and just below it the frequency selectors for the MHz and kHz digits. The operating frequency is mechanical digitally displayed in a small window.
In the lower left corner of the front panel, there is the SQUELCH switch: in the SQUELCH OLD operation mode, the receiver is switched on by an incoming signal of a certain level; in the NEW position, it is switched on by a 150 Hz tone from another set of the VRC-12 / PRC-77 family, so that this function can only be used to communicate with stations from the same family of radios. The volume control is right next to it. To the right of the channel table, the dial illumination and loudspeaker switches are located, followed by the main power switch, which also switches from low to full transmit power.
Below that, in the middle of the front panel, are the connections for relay operation, the microtelephone and the control for the automatic antenna tuner.
On the right, at the top, is the antenna socket and below it the internal speaker, protected by an impact-resistant perforated cover.
The R-442/VRC auxiliary receiver essentially consists of an identically designed receiver section with similarly arranged controls on the front panel. The auxiliary receiver can be used, for example, to pick up radio messages from a superior level while transceive operation is in progress within a station group on a different frequency.
The AM-1780/VRC on-board intercom system was also used in the Swiss Army for communication within armoured vehicles. The C-2299/VRC relay switching unit is used to set up a relay station from two RT-524s.
Technical principle
Transceiver
Components
The set is completely solid state.
Development
The frequency-modulated VHF radio was developed by the American Avco Corporation and introduced to the troops around 1963. With the procurement of the American M113 armoured personnel carrier, the Swiss Army acquired the first VRC-12 radio stations, which were supplied as standard with the armoured vehicles. It was subsequently used in various vehicles and also as a fixed station: with a lifespan of use from 1963 to 2003, the SE-412 was one of the longest-used radio sets in the Swiss Army.
