11-12-2008, 04:57 PM
I'm working on the above and have finally got the FM working well after alignment of the IF. I went to adjust the FM detector xformer and in the first step, I got no response from adjusting the trimmer. I used my scope/counter and looked at the detector oscillator and it was running at 10.4 MC and the trimmer did nothing to change the frequency. I measured the resistance between the yellow and white wire coming out of the oscillator section of the xformer and got about 6 ohms. I am not the brightest bulb when it comes to electronics but it appears from the schematic that should read infinite due to caps in the can. Am I wrong? Tuning in an FM station and turning either the trimmer or adjusting the coil has no affect on the signal reception. I don't see how it can work with the IF frequency running 9.1 MC and the detector oscillator running 10.4 MC. Can anyone out there shed a little light on this?
Jerry
Jerry
A friend in need is a pest! Bill Slee ca 1970.