help with L22

[1iwilly]

Today, while using my 2K on 38 LSB, I left it on for a few hours. When I came back, I noticed that the frequency had drifted up. I attempted to re-tune L22, but the issue persisted. after sitting Is there a method to make the slug a little tighter? I attempted to do so, but it did not work.

 

[sp5it]

Slug doesn't turn by itself. Reason of drift is elsewhere.

 

[1iwilly]

Slug doesn't turn by itself. Reason of drift is elsewhere.

would it be possible for the tunning can be going bad ?? am doesn't do it USB doesn't do it either

 

[sp5it]

Usually reason of drift is aged ceramic capacitor somewhere in L22 circuit, changing it's parameters when warming up. Could be also varicap voltage fluctuating. Basically old age issues.
Mike

 

[1iwilly]

Usually reason of drift is aged ceramic capacitor somewhere in L22 circuit, changing it's parameters when warming up. Could be also varicap voltage fluctuating. Basically old age issues.
Mike

 

[1iwilly]

I'll have to wait until the temperature returns to the usual 80 degrees here in Florida before I can begin tracing it. It's too hot in the garage. Thank for the replies

 

[1iwilly]

I discovered a faulty solder spot on the bottom of L22 which caused it to drift. Whenever I applied slight pressure on the L22 tower, it would come back on frequency.

 

[Cable Guy]

would it be possible for the tunning can be going bad ?? am doesn't do it USB doesn't do it either

Yes, I have seen faulty tuning cans. After pulling most of my hair out, I learned to never assume they're fine or are in spec. Many have a small capacitor that can fail or drift, throwing the tuning range out the window.