Topband: Wideband Balun...?

[Rick Karlquist]

Eddy Swynar wrote:

>
> Is there really & truly such a thing as an air core 4:1 balun that will
> cover the entire spectrum from 1.8- to 29.7-MHz...? I've looked & I've
> repeatedly searched on the internet, but can not quite come up with such

Basically, you are describing the old Heathkit balun.
It has two bifilar air core coils and is designed
to convert 75 ohms to 300 ohms.  Covers 80 through 10 meters.  (Not
160 meters).  You could probably start with two of these and combine
the coils to get down to 160.

See:

http://tubularelectronics.com/Heath_Manual_Collection/Heath_Manuals_B-D/B-1/B-1.pdf

I actually have one of these rare baluns, but I've never used it for
anything.  It might be fun to hook it up to my Agilent 4 port
network analyzer and characterize it in even and odd modes.

Rick N6RK