Towertalk
[Top] [All Lists]

Re: [TowerTalk] Balun Recommendation

Subject: Re: [TowerTalk] Balun Recommendation
From: Steve Hunt <steve@karinya.net>
Date: Sat, 21 Apr 2012 17:57:26 +0100
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Frank,

The centre conductor of the coax and the inside surface of the braid 
flow currents that are balanced - equal in amplitude but with a phase 
difference of 180 degrees; they wouldn't produce any net flux in a 
ferrite core that the coax was wrapped around, so the presence of the 
core doesn't affect them. The core only affects the CM signal.

73,
Steve G3TXQ


On 21/04/2012 17:43, Frank wrote:
> Joe Subich, W4TV wrote:
>
> I have a basic question regarding CM chokes.  My understanding is that
> you make a choke by windng the feedline around a form to create an
> inductance.  If the inductance is sufficient it bucks the CM current
> trying to sneak back into the shack.  All the conductors in the feedline
> are coiled.   Even the center conductor is coiled and probably has
> inductance as well.  Won't that buck the signal to the antenna?  On
> receive as well as transmit.
>
> Could it be that preceived noise reduction is nothing more than a signal
> reduction?
>
>
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>