Topband: I need help proofing an Inverted L model I made please. 40

[Artek Manuals]

Especially if you have elevated radials you will need a choke otherwise 
the coax and your shack will become part of the ground plane. . In my 
case I have a choke ( for common mode currents) and UNUN to match the 25 
ohm impedance of the antenna to 50 ohms. In some installations the 
common modes� can be quite large . The choke on my� 60'-"t" is eight 
ft-240-31 cores with 4 turns of coax. At 4 cores, the cores would get 
hot enough after 10 minutes at legal limit that were too hot to touch. 
With ground mounted radials the common mode problem is usually a lot lower.


YMMV
Dave
NR1DX

On 12/10/2020 2:17 PM, Jim Brown wrote:
> On 12/10/2020 4:33 AM, Rob Atkinson wrote:
>> I've never understood what is gained by using a balun at the feedpoint
>> in this application.�� The feedline is unbalanced as is the load.
>> What's the point of a balun.
>
> That's the problem with the word "balun." A CHOKE is needed at the 
> feedpoint so that the feedline does not become a radial.
>
> 73, Jim K9YC
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband 
> Reflector

-- 
Dave Manuals at ArtekManuals.com www.ArtekManuals.com


-- 
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus