[TowerTalk] feedpoint choke for inv L

[David Gilbert]

I still don't understand.  If you put a choke at the feedpoint you still 
have coax laying right next to radials for whatever the length of the 
radials are.  There has to be coupling to the coax from the radials 
AFTER the choke.  Even the part about blocking shack noise doesn't make 
sense to me since whatever shack noise might be present on the coax can 
couple to the radials unless the choke is outside the radial field.

Dave   AB7E


On 11/19/2018 1:29 AM, Jim Brown wrote:
> On 11/18/2018 10:49 PM, David Gilbert wrote:
>> I've never understood the value of a feedpoint choke for a typical 
>> ground mounted vertical antenna,
>
> It prevents the feedline from becoming part of the radial 
> system/counterpoise, and thus part of the antenna. Without a choke, 
> there is the potential for RF in the shack, and for noise coupling 
> from the shack to the antenna. I have no serious observations about 
> either in the field, but I do use a choke at the feedpoint of my three 
> 160M verticals. If you roll your own, the cost is modest.
>
> 73, Jim K9YC
>
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