Precision Resistors

[Fred Olsen]

Charles Seitz wrote:
> File the body of a close value carbon resistor
> to bring it to your desired resistance.
> You might also try it with a 1% metal film
> resistor.

This is an old barnyard technique that will actually work, to an extent.
  There are a few caveats though.  One should condition the resistor at
perhaps 50% power for several hours.  The "filing for values" will work
best on old U.S. production Allen-Bradleys, due to their high
compression and tight process controls.  And it's pointless unless you
coat the wound with something to exclude moisture and contaminants.
Q-Dope or what have you.

If you do this on metal films you'll end up with resistors all right -
with a value of infinite.

Fred
--
<><
--
Outgoing checked by Norton AV

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=HEATH
To post - HEATH at LISTSERV.TEMPE.GOV
Archives - http://interactive.tempe.gov/archives/HEATH.html