The R107 Communications Receiver

See four of these sets in the virtual Radio Museum


see high definition pictures

 A pair of R107 receivers

The top receiver is basically original but the lower one has received, what in the 1950s and 60s would have been normal de-militarisation for its use as a general coverage set for a short wave listener.

Nowadays a collector of such things will demand an original example, restored to the condition as it would have been in the 1940s.

Weighing in at 96 pounds the R107 would have been used in a fixed station or a heavy vehicle. Coupled with a 52 transmitter it could have been used for networks containing the portable Wireless Set No.18 or those used in tanks, Wireless Set No 19.

Frequency coverage is 1.2Mc/s to 17.5Mc/s in three bands

The valve line-up...

RF stage, ARP34 (EF39), mixer ARP34 (EF39), local oscillator AR21 (EBC33), two IF amplifiers ARP34 (EF39), audio amplifier AR21 (EBC33), BFO AR21 (EBC33) and audio output AR21 (EBC33), rectifier 6X5G

Power was supplied from AC mains or a 12 volt battery through its built-in vibrator.

As if the weight of these things wasn't already enough there is a steel lid that fits over the front, keeping the effect of bullets and the like to a minimum. Usefully a complete circuit diagram is glued in place over the inside surface. Maybe this is the first set where real thought went into servicing in the field, as not only is there a circuit diagram supplied but the valve complement has been limited to only two types (excluding the rectifier) thus dramatically improving logistics. First level fault-finding could be to merely switch a couple of valves around.

The most sought after examples of the R107 have a front cover and one of mine has a rather rusty example whose inside surface carrying the circuit diagram is shown below.


Circuit diagrams- where you can see that only valve types ARP34 (EF39) and AR21 (EBC33) are used in the receiver.

R107 Front End

R107 IF and LF sections


R107 Power Supply





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