[AMPS] Re: resistance

[w8jitom@postoffice.worldnet.att.net]

> From:          "George T. Daughters" <gdaught6@pobox2.stanford.edu>

> it is perhaps important to note that an increase in the resistance of 
> a composition resistor (or a film resistor, too) can increase when 
> the resistor gets too hot.  (rich has said this, too.)  it doesn't 
> have to be so hot that it bakes the color bands to new colors.  the 
> point i want to convey is that it doesn't *have* to be a parasitic 
> oscillation that causes this change.  i've seen resistors in dc power 
> supplies increase by a factor of 3 or 4 by chronic overheating, but no 
> smoke was emitted.
> 
> 73,
> George T. Daughters, K6GT

A good saleman never admits anything other than his product or 
"invention" could be a cure for all ills. The goal is to sell 
suppressor kits, not help people understand how things work and why 
things really fail.

Most carbon resistors age and change value when exposed to heat, 
unless they are used in an amplifier. Then suddenly the rule 
Carl, you, I and a hundred others know changes. Only a parasitic can 
make them age off value, according to ONE guy.

73, Tom W8JI

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm