The inevitable callback on RCA 17PT8072

[old_coot88]

Originally Posted by Electronic M

Looks like they used a couple of adjacent parallel traces to form a capacitor to bridge the IF signal across the deleted tube...A very interesting approach!

Heh. Quite a 'gimmick'.

[init4fun]

Originally Posted by old_coot88

Heh. Quite a 'gimmick'.

Yes Sir , I am familiar with the "gimmick" capacitor from my tube FM radio work . It would usually appear as two wires lightly twisted together but of course not electrically connected together . An easy way to get a couple of picofarads without an actual component and somewhat adjustable by twisting tighter or loosening the twists . A neat way to accomplish a desired result

[Phil Nelson]

Not to go too far off topic, but speaking of unusual traces . . . when recapping my CTC-4, I noticed these two squiggly guys:



??

Maybe that's commonplace in PC boards, but I don't work with them often.

Phil Nelson

[kvflyer]

Originally Posted by Phil Nelson

Not to go too far off topic, but speaking of unusual traces . . . when recapping my CTC-4, I noticed these two squiggly guys:



??

Maybe that's commonplace in PC boards, but I don't work with them often.

Phil Nelson

I suspect it is an inductor?