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To: Bill Turner <>, Amps group <>
Subject: Re: [Amps] THE SKINNY ON MY AL-82
From: Colin Lamb <>
Reply-to: Colin Lamb <>
Date: Sun, 21 Dec 2014 13:46:19 -0800 (GMT-08:00)
List-post: <">>
Regarding carbon comp resistors:

"Not necessarily. Carbon comp resistors can drift both up and down in
value.  I've been replacing them all my life, trust me on this one.
They are essentially unpredictable."

Many years ago, I tested some 2 watt 250 ohm carbon comp resistors for 
stability.  I heated them up to dissipate 2 watts in open air.  After a 
relatively short period of time (I do not recall the time, but it was a number 
of minutes), I measured the resistance and it had increased.  I thought I could 
go through a number of cycles and have it stabilize.  But, every time I ran it 
through a cycle, the resistance changed.  At first, it went up in resistance.  
But, soon it started going down.  It never was stable.  And, each resistor was 

I have numerous old Allen-Bradley 1/2 watt resistors on the shelf and some are 
stable, while some are not.

Colin  K7FM  
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