The on-off switch seems to have more resistance that it should but after I sprayed some degreaser into it, it seems to be OK. You can see the two blue electroylitic capacitors I added to the power supplyĪ long time ago, someone replaced one of the audio transformers - that fix is still good. I have it wired correctly now and there is no hum. And the fix that someone did long ago did not wire the power circuit per the schematic. I rewired the power supply because one of the old filter capacitors was still in the circuit from a fix long agoĪnd the set had a lot of hum. The substitute winding is an AM radio RF coil that I purchased. The picture below shows the newly-mounted substitute coil winding.
#Blue rca victor radio install
The pot seems to be OK now and the front end and local oscillator work properly.Īfter I fixed the pot, a coil winding in the RF stage opened (the front end went dead) and I had to install a substitute windingĬlose to the large coil assembly underneath so it would couple into the next stage. The picture below shows the repaired pot.īelow is the repaired pot with the wiper in place. I opened up the pot and used silver paint (paint with silver in it) to short out the open. The local oscillator did work initially but when the volume control pot opened, the local oscillator quit working. The front end RF amplifier and the local oscillator are connected to the volume control. It took me a while to figure that out because the tube tested good initially.Īfter a while, the volume control pot opened and the front end was dead. That confused me for a while because the B+ could not be maintained and I thought I had a short, but it was the tube giving up. The #80 rectifier tube would initially work, but it soon could not produceĮnough emission to power the radio. The other five tubes were either very weak or had open filaments. I first checked all of the vacuum tubes and only 3 of the 8 tubes were good, and those were the two # 35 tubes and the #80 rectifier tube. However, this radio had a lot of electrical problems. The radio looked in good physical shape when I received it. Thus you can use the audio section (the #27 detector tube and the two #45s) to amplify the phonograph audio. On the rear of the radio, there is a terminal strip where you can inject the audio from a magentic pick-up (phonograph). The circuit is a single conversion superheterodyne with an intermedate frequency of 175 kHz. If there isĪ lot of static from thunderstorms, the static crashes will be extremely loud and overwhelm the audio program. You are listening to a station whose signal strength is not constant, the volume will go up and down. Although it isĪ superheterodyne circuit, it has no automatic gain control (AGC) so the volume will vary with signal strength. The radio is AM only and has eight vacuum tubes.
This radio is a 1931 RCA Model R7A Superette. 1931 RCA Victor Model R-7A Superette 1931 RCA Model R-7A Superette
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