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Thread: Bearcat 980 alignment

  1. #1

    Default Bearcat 980 alignment

    While putting a Bearcat 980 (the newer one with less tuning coils inside) back on frequency I ran into trouble. Being my probe loads the oscillators too much to measure frequency (and there is only one oscillator having an adjustment anyhow), I added 1kHz modulation and measured it coming out of the back end. I was able to get the AM and USB transmit back on frequency with no trouble but the LSB coil wouldn't adjust enough to get it on frequency. With the ferrite screw completely removed, I was only able to get it up to 27.20381 MHz (Ch 20 LSB, 1kHz modulation - shooting for 27.204). I had to use a piece of threaded brass in place of the ferrite screw to get it up to 27.204. Anyhow, the radio is working great and people report that its right on as my counter suggested, but I am still left wondering... Why would it come out of the factory so far off that parts need changing? The guy I'm repairing it for said it hasn't been opened or modded in any way and I see nothing altered either.

    Has anyone ran into this before?

  2. #2
    Super Moderator 5B4AJB's Avatar
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    You might want to remove & measure some of the capacitors near that inductor.
    Don't buy cheap ones off ebay either, get yourself some real "low ESR" types if its for a radio...

  3. #3

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    There was only one in the vicinity but I doubt it would be the cause as the oscillator works fine switched to the other coils. I might have to look into the switching diode that selects LSB. I wish there was a schematic but its not online from what I can see. I might test that one anyhow. Thanks!

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