Re: TR-4C Problems with 28.0 and 28.5 bands
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Dave, I had a similar problem a number of years ago with a TR-4. The crystal oscillator will "free wheel" when the tuning is not exactly at the frequency of the crystal. The result was the same or similar to what you hear.?
Try adjusting the proper coil (I don't remember which one) for the 10M band until the oscillator "locks" to the crystal.
GL ES 73, Bob Loving K9JU
Maryville, TN
On Saturday, January 18, 2025 at 03:24:19 PM EST, Dave KD5FX via groups.io <land.dave@...> wrote:
OK, more work done today! I did check and double check all the contacts on the band switch, especially those around the Xtal area. They are all good and tested good for continuity. There's a big contest going on today and I was able to hear some signals on the 28.5 band and the 28.0 band too! BUT they are very distorted, you can tell it's SSB but can't understand a thing (and yes, I tried both LSB and USB). Even the CAL signal is distorted. Not a pure tone, almost a buzz sound. All the other bands are working OK including the 29.1 band, I can hear the CAL signal fine there. Oh yeah,? I swapped another 6EA in there for V1, no change.?
Thanks for everyone's help so far, any other ideas??
73, Dave KD5FX
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