On 11/25/2012 12:21 PM, Tom Horne wrote:
Thanks to the generosity of a fellow radio club member I now have the
use of a Yaesu FT-1000 (no Suffix). Since it has a built in antenna
tuner, that I'm hoping to use, I need to ask what the best way is to
couple the window line that feeds my folded dipole antenna into a
short; say twenty feet; coaxial feeder from the radio. ...

So is a balun a good solution to this challenge or should I resort to
the two pieces of coax in parallel that I have read of elsewhere?

IIRC, your antenna is about 90 feet long: that makes it a "natural" for
the 60 meter band, so I suggest you try using a 6:1 or a 4:1 balun, and
see if the built-in tuner will work with it. If 60 meters is OK, try it
on 20 and 10 meters, but 15, 40, and 80 are going to be iffy.

I don't like the "choke" baluns that use toroid cores over the coax,
since I've had problems with them overheating, but you can make a balun
with a short length of PVC pipe: just wind one layer on the pipe, cover
it with some Mylar, and wind the other side over that. The ARRL handbook
has the formulas, which I can't recall offhand, since they are buried
back in the mists of time and/or my misspent youth. ;-)

When your balun is tested, and the turns ratio adjusted as needed, you
can cover it in plastic to keep moisture out, and leave it outside so
that you can keep using Coax for your feedline.

HTH.

Bill

--
Bill, W1AC