Towertalk
[Top] [All Lists]

Re: [TowerTalk] Common mode choke.

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Common mode choke.
From: "Joe Subich, W4TV" <lists@subich.com>
Date: Thu, 09 Oct 2014 17:18:16 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>

Choke any lines leaving the tower.  Anything on/parallel to the
tower is part of the antenna.

73,

   ... Joe, W4TV


On 2014-10-09 4:31 PM, Mike Reublin NF4L wrote:
Thanks, Joe.

3 of the lines go to a switch on the tower. Would a choke on the single line 
from the switch to the shack be sufficient?

Mike

On Oct 9, 2014, at 4:20 PM, Joe Subich, W4TV <lists@subich.com> wrote:


Since 1/4 wave slopers use the *tower* as the ground return, you will
almost certainly need a second common mode choke at the base of the
tower.  Any antenna current on the tower will be coupled to the
feedline where it runs parallel to the tower.

In other words, if you are using a shunt fed tower, 1/4 wave sloper,
N4KG reverse fed ground plane, etc., place common mode chokes on *all*
feedlines *at ground level where they leave (the vicinity of the tower.*

Even on a grounded tower, the feedlines strapped to/or running parallel
have antenna currents both capacitively coupled to, and induced on the
outside of the coax shield.

73,

   ... Joe, W4TV


On 2014-10-09 3:01 PM, Mike Reublin NF4L wrote:
I wrapped the coax for my 1/4 wave slopers thru 6 toroids. The bundle hangs so 
it touches the tower. Zat OK?

73, Mike NF4L
_______________________________________________



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

_______________________________________________



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

_______________________________________________



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

_______________________________________________



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

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