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Have some odd variations from schematic
3 Attachment(s)
I picked up an airline 94BR-1535a and have recapped it. I also replaced missing tubes. AM works fine but FM is just static. I started digging deeper and noticed a couple of irregularities. T7 has a small cap bridging one side and what looks like a dog bone resistor bridging the other side. Can't find this on the diagram. Anyway, the resistor tests open. Was this some repair or factory adjustment? Also, from T9, there's a 3.3m resistor where c22 is supposed to be. Did someone mistake a color coded cap for a resistor? I've reinstated c22 and AM seems to work better. I've also ordered new FM tube 6au6 for kicks.
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What you are describing for T-7 is silver mica creep. What looks like a dog bone resistor, is a ceramic cap. more than likely you have at least one more transformer with silver creep. If you have a signal generator try to feed a 10.7 megacycle signal through. Using a signal tracer try to follow the signal till you lose it, then start testing parts in that stage. All the best, Tom
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How about posting a pix of the under chassis area of the transformer in question? All the best, Tom
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Ok, It was actually T5, not T7 bit the same applies. The brown cap on the left was removed while I tested it and was replaced with longer leads due to the tight space. The ceramic "dog bone" is on the left.
http://uploads.tapatalk-cdn.com/2016...7c17a10503.jpg Sent from my SAMSUNG-SGH-I337 using Tapatalk |
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Thanks. I'll leave it be. Going to wait on a new tube before doing much else. Been tracing the schematic tonight just to verify everything is where it's supposed to be.
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True. I actually knew that but didn't think to apply it.
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I put this radio aside for a while but went back to it today. Discovered totally by accident that if I leave the 6AL5 fm detector out, I can tune in some fm stations. I have it wired according to schematic but I am curious about the 10uf cap with the + side to ground. I have an extra tube which supposedly checks good so I should be OK there. Any thoughts?
http://uploads.tapatalk-cdn.com/2016...706d2993a9.jpg Sent from my SAMSUNG-SGH-I337 using Tapatalk |
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