[Test-Equipment] Tektronix T935A Scope - seized knobs

[Barry]

> Found no binding on the knobs. I had to open the cabinet and look 
> internally.
> Followed VAR knob shafts to 1k pots on board - Found seizure to be in 1k
> pot bushings.
> Sprayed bushings lightly with Chemtronics "Trol-Aid" from 1970's.
> Worked in lube and they slowly loosened up enough to turn from front red
> VAR knobs with just fingertips.
> Will re-assemble tomorrow - how much should I charge myself ?
> 
> Back to tube radios,
> 
> bob...w2ami x wn2ami 1962

I had a similar thing occur on a Tek 465B I recently acquired (okay, "won" on eBay).  The "Focus" pot was extremely difficult to twist.  I worked in some DeOxit (yes, I know, it's not exactly the correct chemical for the job but it worked).  The shaft eventually was very free to turn; however, about a week or two later, it is beginning to show signs of hardening lube again.  Looks like a more permanent solution is to disassemble the pot and clean it correctly.

73,
Barry - N4BUQ