"Richard Clark" wrote in message
...
On Tue, 14 Sep 2010 19:11:43 -0400, "Ralph Mowery"
wrote:

That is what I am using on a home built version. Using a 4:1 voltage
balun
at the feedpoint

This is like using a lighter to find a gas leak in the basement.

and the ferrite bead type about 20 feet down from the
feedpoint.

The ferrite choke is doing something as it gets warm while running around
about 1 KW to the antenna. Doesn't heat up when going into a dummy load.

Hi Ralph,

Through the 4:1? Probably not, or you would have said so (and
unlikely you have gone to the trouble to build a 4:1 dummy load).

As the dummy load is most likely enclosed and shielded, then that
suppresses common mode currents due to your test transmission.

And, yes, when your ferrite choke (AKA 1:1 BalUn) heats up that is due
to common mode currents that were not snubbed by the voltage balun (by
design - so why choose it?).

Add a second ferrite choke (AKA 1:1 BalUn) at the feedpoint -before
feeding the voltage balun.

My 'Windom' usually works beter than an 80 meter dipole on 80 meters plus
gives me the option to operate several other bands.

Better in what sense?

73's
Richard Clark, KB7QHC

I tested the bead choke just by going from the amplifier to the dummy load.
I did not have the 4:1 balun in the line with the dummy load. The dummy
load was 50 ohms. I just ran this test to make sure the beads were heating
up and not the coax. It is a comercial bead choke and the coax was about
the size of rg-58. Suspose to be some kind of higher power rated coax good
for over 1 KW. I just wanted to make sure it was power on the outside of
the coax and not inside the coax. If inside the coax, then it would have
heated up while going into the dummy load as has been mentioned by this
thread.

The 80 meter dipole and the 'Windom' are at right angles to each other
suported on the ends at 50 to 60 feet. In almost all cases the signals are
usually much beter on the Windom. It seems the only time the dipole is
beter is when the stations are almost off the end of the Windom. Stations
around 45 deg to both antennas still give the windom a beter signal.