[sdiy] strange PCB faults, was:OTA question

[Paul Perry]

That takes me back.. back to before I was  born,
when it was actually common to use a pencil line as a
grid leak resistor in radio detector stages!
In fact, back then, the pencil mark was probably more
stable than the average 10M resistor was back then.

paul perry Melbourne Australia

----- Original Message ----- 
From: "Oscar Salas"

> Little off-topic but one day I was making modifications and studying a 
> CVADSR in its PCB. I noticed a lot of offset in one output. Uau was a lot 
> of time wondering why since all was theoretically OK, until I noticed that 
> was a mark that I did with pencil that was acting as a resistor.