[TowerTalk] Adding an RF choke

[Mpridesti]

This will be an elevated  2 element phased vertical system using the Christman design with 50 ohm feed lines. 

Regards,

Mark, K1RX


> On Dec 2, 2024, at 6:18 PM, Jim Lux <jim at luxfamily.com> wrote:
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> how deep is it buried?  Skin depth of the soil at HF isn't zero (except for those folks with the array in a salt water marsh, and even there...), so the shield of the coax acts as a radial. Although the choke would affect that, as well since it chokes the current on the outside of the coax.
> 
> One big advantage of feedline chokes is that they make the behavior of the overall system more "predictable".
> 
> 
> On Mon, 2 Dec 2024 14:49:44 -0500, <john at kk9a.com> wrote:
> 
> I used a small diameter 75 ohm PTFE coax for the choke and shortened the
> feedline accordingly.
> 
> I wonder of a ground mounted vertical with buried coax really needs a choke?
> 
> John KK9A
> 
> 
> 
> K1RX 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
> 
> 
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