[ARC5] PS Hum in BC-453-B (solved!)

[Glen Zook via ARC5]

No shield on regular Category 5 cable.  The wire pairs are twisted, each pair in a different pattern, to reduce hum pickup, etc. Glen, K9STH

Website: http://k9sth.net
      From: Roy Morgan <k1lky68 at gmail.com>
 To: Bill Cromwell <wrcromwell at gmail.com> 
Cc: ARC-5 List <arc5 at mailman.qth.net> 
 Sent: Thursday, January 29, 2015 8:07 PM
 Subject: Re: [ARC5] PS Hum in BC-453-B (solved!)
   

On Jan 24, 2015, at 9:15 PM, Bill Cromwell <wrcromwell at gmail.com> wrote:

> ... I'm operating my BC-453 from brom batteries on both the heater strings and the B+. I'm thinking the exposed, randomly strung wires from the batteries are picking up a small amount of hum from the nearby power lines and their wonderful field. … I will replace those wires with shielded cables ...

Note that Cat 5 computer data cable is especially constructed to reduce pickup from external fields.  I think it has 4 pairs of conductors and the shield.  You could run the filament current through two pairs and the B+ through a third pair.