[Elecraft] 9:1 Balun

[Thomas Horsten]

Many manual ATU's consist of a variable capacitor and a tapped inductor.
It's a matching network but also works as an "on-the-fly" switchable balun.
The difference is the location. The ATU typically sits at the rig end where
a balun sits at the antenna feedpoint (and so may present the coax with a
better matching impedance, plus acts as a choke reducing common mode
current). You can have a remote-controlled automatic ATU at the feed point
in which case you'll always have a perfect match for your coax. Great for a
stealth multiband in the attic, but it's an expensive and clunky solution
for portable operations.

73 Thomas OZ5TN (aka M0TRN, AF7BE)

On 1 February 2017 at 02:35, Kevin - K4VD <kevin at k4vd.net> wrote:

> One thing I think would be great to have, especially built in as part of an
> antenna tuner, is a switchable BALUN. When someone needs to throw up random
> antennas it would be handy to be able to just switch in the appropriate
> ratio. Can a BALUN be tapped maybe? It seems it would extend the range of
> internally antenna tuners also. I should know this stuff. But I don't.
>