Topband: Beverages Noise

[Jim Brown]

On 1/30/2012 5:33 PM, Silvio M. Martín LW9EOC wrote:
> As I can remove noise entering through the ground? and how to isolate the shield?

A common mode choke, made by winding many turns of the coax around a 
ferrite core, would help.  The best core to use is Fair-Rite mix #31, 
and you want at least 14 turns through a 2.4-inch outer diameter toroid 
for 160M.  7-9 turns through a big one-inch inner diameter clamp-on will 
work.

Study http://audiosystemsgroup.com/RFI-Ham.pdf  for details, a 
discussion of how and why this works, part numbers of useful ferrite 
cores, and a list of known good sources in the US.  See the Fair-Rite 
website for a listing of international distributors.

73, Jim Brown K9YC