Symptums and Solutions: Philco 48-460

[Reece]

Good that you got it going. The easiest way to see if an oscillator is working is how I described. The oscillator is a mini transmitter and you're picking it up on the other radio. You are actually doing two tests in one: first, it proves the oscillator is working, and second, with the Philco on 1000 and the second set picks it up around 1450, it proves that the IF is reasonably close to its proper 455.

You could use a VTVM or DVM to see if there's negative voltage on the oscillator grid, but there's nothing more positive and simple than the second radio trick. Imagine that you proved the oscillator was working but the set still didn't play. Now you could use the signal tracer in the IF stages and follow towards the audio section to see where you lose the signal. Or use the AF output of the signal generator in the audio section to prove it's OK and then switch to modulated 455 RF output ahead of the detector and into the IF stages. It would be good to read up on the uses of this equipment and then try it out on a working radio.