----- Original Message ----- From: "Jim Brown" <[email protected]> To: <[email protected]> Sent: Tuesday, January 31, 2012 11:51 AM Subject: Re: Topband: Beverages Noise
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. ** A good feedline only ground rod that is completely isolated from the Beverage transformers antenna winding ground rod by 5-10 meters should be the first step. ON4UN's latest revisions go thru this in detail. The ferrite is useful for minimizing any common mode that remains. Carl KM1H _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
