Re: Slightly Unbalanced dipole?

Posted by Vic Rosenthal on Jan 14, 2019; 6:12am
URL: http://elecraft.85.s1.nabble.com/Slightly-Unbalanced-dipole-tp7648044p7648088.html

Why would a common mode choke at the antenna feedpoint present more problems than the common practice of feeding a balanced line through a single-ended tuner and balun?
I’ve done a lot of experimenting with the latter and have learned that a) the best configuration is with a 1:1 balun, and b) the balun will become lossy and heat up if the impedance it sees is highly reactive. The solution to b) is to cancel the reactance by putting the appropriate opposite reactance in both sides of the line between the balun and the antenna. Of course this means added complexity.
I would love to figure out how to make a choke that would work with balanced line at the antenna feedpoint, on multiple bands without any additional components.
FWIW I’ve switched to a real balanced tuner (Johnson Matchbox).

Victor 4X6GP

> On 14 Jan 2019, at 1:42, Al Lorona <[hidden email]> wrote:
>
> By the way, whenever Jim says, "...a very good common mode choke at the feedpoint of an antenna...," he means an antenna fed with coax. For the rest of us, of course, that choke would (should) go at the output of the antenna tuner, whether in the shack or close by.
>
> Al  W6LX
>
>  
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