OK, here is what I would do. First, thoroughly inspect the area of the oscillator circuit with a magnifier and good lighting. Look for suspicious solder joints (especially where a connection is made through a plated through hole, a.k.a. VIA), copper trace breaks, hairline shorts, etc. Clean any flux residue you might find. Take the piston trimmer apart to see if you can figure out why it is binding. There is no advanced phlebotinum or magic server pixie dust inside, it is just cleverly made from common materials. You could probably make one with materials from Ace Hardware. Or find a replacement that is close in value and about the same physical size or smaller and adapt it to fit. It is only two electrical connections.
We learn. 35 years ago the TR7 scared the hell out of me. After a lot of tinkering and a few mistakes I understand it pretty well. In the end it's just a radio, made out of dirty sand and carbon. And it is user serviceable.
73
-Jim
NU0C
On Thu, 22 Feb 2024 15:31:51 -0800
"Bill NZ0T" <nz0tham@...> wrote:
Jim I understand but not all of us have your expertise and sometimes just want to the radio working lol.? I had no trouble at all with the 20 WPM part fo the old Extra test but the theory was a big time struggle for me.? Sometimes I can muddle along and fix something but I'm a horrible tech.
73, Bill NZ0T
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73
-Jim
NU0C
Jim Shorney