News:

Forum may be experiencing issues.

Main Menu

Carbon comp tolerance

Started by beneharris, June 13, 2016, 08:50:17 PM

Previous topic - Next topic

beneharris

I bought a huge bag of carbon comp resistors off of ebay. Some of them read dead on with my multimeter, but some of them, which are 5% are reading double, to triple that. The worst offenders are a stack of 6.8ohm that read anywhere from 7.4-7.9. I'm thinking they're just really poor quality, but even so, that surprises me. Is this just carbon comp? I'm not super worried about using them, just surprised at the difference between the seemingly same value resistors.

EBRAddict

Either your multimeter is malfunctioning or those are crap parts.


beneharris

I'm going to go with crap parts. I used 2 different ones. That's okay, I didn't pay much for them.

lincolnic

You might want to try replacing the battery in your meter anyway to see if that changes anything. They behave really strangely with low batteries.

alanp

Carbon comps are not known for accuracy as a whole.

It's part of why back in the day, you'd sometimes get that one amp with ungodly mojo, or that perfect fuzz that sounded like nothing else. All the bad tolerances threw the values out of spec, and the planets aligned, and the collective bad tolerances added up to something beyond what the production spec was, and you got lucky that it sounded good.
"A man is not dead while his name is still spoken."
- Terry Pratchett
My OSHpark shared projects
My website

beneharris

Quote from: alanp on June 15, 2016, 07:20:44 AM
Carbon comps are not known for accuracy as a whole.

It's part of why back in the day, you'd sometimes get that one amp with ungodly mojo, or that perfect fuzz that sounded like nothing else. All the bad tolerances threw the values out of spec, and the planets aligned, and the collective bad tolerances added up to something beyond what the production spec was, and you got lucky that it sounded good.

See, I thought that, too. But this just seemed so far out of line that I kind of threw that theory out the door. Maybe I'll breadboard a fuzz and see how it takes with them.