Towertalk
[Top] [All Lists]

Re: [TowerTalk] Adding an RF choke

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Adding an RF choke
From: "Jim Lux" <jim@luxfamily.com>
Date: Mon, 02 Dec 2024 18:04:09 -0500
List-post: <mailto:towertalk@contesting.com>
        


 
It also kind of depends on whether the phasing lines are also being used as 1/4 
wave transformers (like in a 4 square) or whether it's just the different in 
phase that is important.
In the latter case, then the choke would add a fixed offset to both, so the 
difference remains the same.

I might add that an inexpensive VNA can make setting this kind of thing up a 
whole lot easier, since you can *measure* the electrical length (and the 
impedance transformation) of the cables.


On Mon, 2 Dec 2024 13:36:53 -0600, Robie Elms <ruler55@gmail.com> wrote:

Mark,

I've not implemented what you are planning. In my opinion you must take
any phase shift created by the chokes into consideration.

If you create the chokes by placing ferrite beads on the coax you would not
change the length, and not introduce any phase shift.

I'm very interested in understanding this issue myself, and look forward to
hearing from others.

Robie AJ4F

On Mon, Dec 2, 2024, 10:44 AM Mpridesti via TowerTalk <
towertalk@contesting.com> wrote:

> Building a set of phased verticals and the phasing lines are critical (of
> course) so my question here: by adding 18 inches of cable length (choke
> length) does the phasing line length need to be shortened by 18 inches?
>
> Or should I consider the choke as part of the antenna and not make any
> adjustments?
>
> Regards,
>
> Mark, K1RX
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> 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>