Wireless of the Week - week 25
 

This week is a little known reception set, the R.P.A. 3. I have never seen an actual example and its development and purpose is a mystery. Any assistance to fill in these details would be most welcome, as would what “R.P.A.” stands for, the manual is silent.

The R.P.A 3 was built by Stewart-Warner-Alemite Corporation of Canada in 1943 which is an odd manufacturer for Canadian wireless equipment and one that didn’t seem to produce any other land sets. It operated on either 110 or 220 volts at 25 or 60 cycles and the manual says it was for stationary or vehicle use. It also had a send/receive switch that put the receiver on standby while some separate transmitter was sending. This infers the R.P.A. 3 was intended to be used alongside a transmitter, the likely candidates being the Wireless Sets No.12, 33 or 53. If this is correct, it seems to be a Canadian alternate for the Reception Set R107.

The set is 20” wide by 22” tall by 15” deep and weighs 130 lbs. It is housed in a steel case that has dome fasteners for a waterproof cover. On the top is a ‘power deck’ that housed the power supply unit, speaker and crystal calibrator as well as a wire antenna and parts box for spare valves and to store the earphones when not in use. The lower portion is the receiver itself. It covers an AM frequency range from 1.5 to 30 MHz in four bands. Reception could be achieved either with the antenna or by line transmission over wires attached to two binding posts on the back of the set.

Interesting set, I've never heard of it either. I wonder if it was another "one hit wonder" like the Vancouver Radio Laboratories model 250. The gov. was known to throw a bone to various companies to keep people employed and to produce a Canadian item.

Interesting set. At first glance it looks a bit like some Radio Direction Finding gear that was around throughout the war, but if that was the case, it should probably have an 'R.D.F.' identifier.

The manual shows a 1944 date, later in the war. Years ago I read a book from the local library on the development of radar equipment during the war, and this really seems to have accelerated towards the end of the war, particularly counter radar measures. I remember a term used being "radar propagation analysis" but cannot for the life of me recall the context in which it was explained. Could this be a piece of equipment related to that type of work?

David