A nice big piece of Pye

[MadMan]

Originally Posted by Electronic M

Somewhere on youtube I once saw a video on using a scope to find the outside foil of a cap.

Yeah I thought that was a great idea to make sure to minimize interference in my stuff when I'm recapping. But then I tried it, and came to realize that you need a super-accurate/sensitive scope to be able to figure out which lead is the outside foil. So like... I figure now if my scope isn't sensitive enough to tell the difference... why bother?

I've ordered from justradios before, their parts seem to be decent quality. But the $25 minimum sucks, so if you miss something in your order you're fucked.

I've used capacitorworld too. They definitely sell cheap shit. And they have a bad tendency to screw up my orders, and they have NO customer service to speak of. But anyway, the way I see it, most old paper caps have a tolerance of +/- 20%, and most modern film caps - even the cheap ones - are usually 10%.

Idk. Also - noice radio!

[Jon A.]

Originally Posted by MadMan

Yeah I thought that was a great idea to make sure to minimize interference in my stuff when I'm recapping. But then I tried it, and came to realize that you need a super-accurate/sensitive scope to be able to figure out which lead is the outside foil. So like... I figure now if my scope isn't sensitive enough to tell the difference... why bother?

Now I'm wondering how you attempted that test with your scope. I finally succeeded with it yesterday by touching the cap leads directly to the BNC port. Hooking it up to a probe would not work. However, my scope goes down to 5 millivolts per division so who knows if it will work with yours.

[MadMan]

Originally Posted by Jon A.

Now I'm wondering how you attempted that test with your scope. I finally succeeded with it yesterday by touching the cap leads directly to the BNC port. Hooking it up to a probe would not work. However, my scope goes down to 5 millivolts per division so who knows if it will work with yours.

I mean, I guess I could've been picking up interference. My scope goes down to 10mV. I'll have to try it straight on the port like you say.

[Jon A.]

Originally Posted by MadMan

I mean, I guess I could've been picking up interference. My scope goes down to 10mV. I'll have to try it straight on the port like you say.

Oh, and don't touch anything metal while you're at it, it'll throw the reading way off. Just a thumb and forefinger holding the cap body and that's it.

I would have used a BNC connector, alligator clips and a short piece of shielded wire as was used in the video but what I did was all I could do in a pinch.

With a probe you'll get the same amplitude with either polarity.