03-28-2014, 09:59 AM
Have you verified that all tubes are good?
If you have a way to inject audio and RF modulated audio, recommend:
1. inject audio signal on the high (non grounded) side of your volume control. If you get the signal strong in your speaker and can adjust volume with your volume control, the circuity is good from that point forward.
2. Inject audio signal modulated by 455KHz (IF) signal on grid of 1st IF tube. If you get signal to speaker, problem is before 1st IF. If no signal, inject same on grid of second IF tube. Same as above if you have or do not have signal.
This should help narrow down where the issue is.
If you have a way to inject audio and RF modulated audio, recommend:
1. inject audio signal on the high (non grounded) side of your volume control. If you get the signal strong in your speaker and can adjust volume with your volume control, the circuity is good from that point forward.
2. Inject audio signal modulated by 455KHz (IF) signal on grid of 1st IF tube. If you get signal to speaker, problem is before 1st IF. If no signal, inject same on grid of second IF tube. Same as above if you have or do not have signal.
This should help narrow down where the issue is.
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
