I've heard people say that old resistors can get noisy. Is that true, and why? I can't say that I've ever observed it.

I'm talking about fixed composition resistors, not pots. I understand why pots get noisy.

Doug,
As an analogy, remember the old carbon microphones. Full of loose carbon granules in a small canister attached to/near the diaphragm. They danced around with movement of the diaphragm. I suppose that a resistor could become uncompressed just a little with age and use, having a few loose granules floating around inside could possibly make a noisy circuit, just like the old carbon mikes that were such a pain. This of course assumes there is some vibration of the resistor to cause the granules to dance around.

marv

:I've heard people say that old resistors can get noisy. Is that true, and why? I can't say that I've ever observed it.
:
:I'm talking about fixed composition resistors, not pots. I understand why pots get noisy.

Hi

Composition resistors in plate circuits can become noisy. This might be from carbon movement as Marv mentioned?

Norm

:Doug,
:As an analogy, remember the old carbon microphones. Full of loose carbon granules in a small canister attached to/near the diaphragm. They danced around with movement of the diaphragm. I suppose that a resistor could become uncompressed just a little with age and use, having a few loose granules floating around inside could possibly make a noisy circuit, just like the old carbon mikes that were such a pain. This of course assumes there is some vibration of the resistor to cause the granules to dance around.
:
:marv
:
::I've heard people say that old resistors can get noisy. Is that true, and why? I can't say that I've ever observed it.
::
::I'm talking about fixed composition resistors, not pots. I understand why pots get noisy.

I had a whole box of 'em....fell right off the bench. ..very noisy.

;-)