05-26-2016, 02:11 PM
As I posted before you will need a RF signal generator capable of emitting an amplitude modulated signal at the FM bc band and at the receivers FM IF frequency.
In order to trace this generated signal you will needs a signal tracer with audio and rf inputs as your Fm detector in your receiver can't demodulate AM. Use the tracer's probe in the RF or Diode setting.
You can start at the Fm ant post at 88mc and trace it though to the plate of the mixer tube. After that you will need to inject a signal at the receiver's IF frequency and trace it though the IF stages.
The caps you mention aren't very critical they look to be a filter to filter rf out the audio before it going to the amp. Short of being shorted I don't think their your issue. The FM IF transformers can't be open because they are in series with the AM IF and if either was open the set would not work on AM or FM.
Terry
In order to trace this generated signal you will needs a signal tracer with audio and rf inputs as your Fm detector in your receiver can't demodulate AM. Use the tracer's probe in the RF or Diode setting.
You can start at the Fm ant post at 88mc and trace it though to the plate of the mixer tube. After that you will need to inject a signal at the receiver's IF frequency and trace it though the IF stages.
The caps you mention aren't very critical they look to be a filter to filter rf out the audio before it going to the amp. Short of being shorted I don't think their your issue. The FM IF transformers can't be open because they are in series with the AM IF and if either was open the set would not work on AM or FM.
Terry
