AN/ARC 5 Medium Frquency Radio Equipment

Following the second world war, the Transport Department installed medium frequency radio telephone equipment in patrol cars. The first radios were war surplus American aircraft radios converted for use in vehicles. These were mounted in the boot of patrol cars and extra batteries were neded to handle the high power drain of the radios.

Left to right- Modulator/Power Supply unit, T21 transmitter , BC454 receiver

 

AN/ARC5 series radio equipment modified for patrol cars.

Thanks to the PoliceMuseum, Porirua

 
   

AN/ARC-5
This series of radios is an updated version of the ATA/ARA and SCR-274N radios. They were used by the US Navy for the latter part of World War 2 and were their main aircraft communication radio. They were fitted in many different bomber and fighter aircraft types for communication between aircraft, navigation, and communication back to base. A fighter would usually have 1 receiver and 1 transmitter fitted. A bomber would often have 3 receivers and 3 transmitters fitted.

 

BC-454 receiver

 
 
ARC 5 Transmitter front panel

DM-32 Receiver Dynamtor
The command sets have a small dynamotor that sits on the back deck of the receiver. It takes 28 VDC (there was a 12 VDC version) and generates 250 VDC for the valves. It has a 3 pin connector under it, so that it can be unplugged for maintenance. It sits on 4 rubber mounts, to reduce vibration.

DM-33 Transmitter Dynamotor
The transmitters use one dynamotor for their High Tension supply. It is continuously rated at 575 volts dc at 160 ma. They only need one, as only one transmitter is on at a time. The dynamotor is located on the BC-456 modulator.