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40-190 image tuning, need help
#1

Hello all. I've been lurking for some time now and decided to try my luck. I have issues with a few Philco's, but I'll start with this one Icon_lol

I've recapped, replaced a few resistors that were out of tolerance. Completely aligned the set and I cannot solve this issue. When tuning stations at the low end of the BCB, you get the station at two different spots on the dial. I'll try to explain this best I can. Example, I tune in 540/kc. As you tune up, the station sort of fades away as it should, then re-tunes again on 550/kc. Almost as strong as on 540, and it sounds slightly different. It does the same thing to stations as you tune up, but the "effect" starts to disappear after 600/kc, and seems to be completely gone by 650/680 kc. The receiver is sensitive, and this effect doesn't occur on the SW bands. One other thing, if you null the received station(weakening it), the effect is also gone or noticed very very little.

I've tried tuning and re-tuning the IFs. I've dropped the IFs to both a low & higher freq setting, this has little effect. One thing I've noticed is IF 37A seems flaky. Meaning it doesn't tune sharp. It seems wide possibly. I'm no expert, but considering the IFs I've tuned in the past. It just doesn't seem right. Any ideas I may be missing. It's driving me nutty Icon_eek Icon_confused Icon_rolleyes
Here's the schematic
http://www.nostalgiaair.org/Resources/339/M0013339.htm

Thanks gents.

Brian

-Brian
If you collect or are interested in antique telephones, please visit Classic Rotary Phones
http://www.classicrotaryphones.com/forum/index.php


Messages In This Thread
40-190 image tuning, need help - by BDM - 09-27-2007, 10:56 PM
[No subject] - by rickd - 09-28-2007, 09:36 PM
[No subject] - by BDM - 09-29-2007, 12:14 AM
[No subject] - by Ron Ramirez - 09-30-2007, 11:08 AM
[No subject] - by BDM - 09-30-2007, 02:47 PM



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