12-24-2013, 05:19 PM
I ran into problems doing the alignment. With a 455kHz signal fed into terminal 1 of the antenna terminal strip as the instructions suggest I had no trouble getting the 1st. IF transformer primary and secondary peaked. I was using my oscilloscope to look at the RF waveform. However I ran into trouble at the 2nd. IF transformer. The plate circuit of this one peaks in a normal manner, but when I go to the secondary at the detector tube, there is a very strong signal there with the secondary trimmer nearly all the way closed. It is as though there is an oscillation happening and the detector tube does not seem to indicate any audio being detected. I had this transformer out and replaced wires in it, however there could still be a problem there. I suspect a possible open capacitor or a loose wire. I need to recheck my connections to the detector tube too. I will do that first as it is easier than taking the IF transformer out again.
Joe
Joe