[ARC5] ARC-5 Pot Taper

[D C _Mac_ Macdonald]

For an example of DC on a variable carbon resistor, consider the direction sensing pot of the CDR type antenna rotators!

They have a history of failures but usually last a long time due to the VERY small amount of current involved.

  
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk at hotmail.com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 
 
 


> Date: Tue, 30 Jul 2013 15:29:50 -0700
> From: jfor at quikus.com
> To: kgordon2006 at frontier.com
> CC: arc5 at mailman.qth.net
> Subject: Re: [ARC5] ARC-5 Pot Taper
> 
> Carbon pots don't much like DC current through the wiper terminal. Think a
> carbon microphone. Through the track- end to end- is generally OK.
> 
> -John
> 
> ===============
> 
> 
> > On 30 Jul 2013 at 21:32, brianclarke01 at optusnet.com.au wrote:
> >
> >> A carbon pot carrying DC would have worn out in a very short space of
> >> time.
> >
> > Please explain. I have never heard of this.
> >
> > Ken W7EKB