I used to make folded dipoles out of 300 Ohm TV Twinlead and match the
feedpoint with a TV balun driving RG-6 to the receiver. It worked
pretty well into an R-390A. Including medium wave, even.

On Sun, 13 Jul 2003 18:49:34 GMT, Telamon
wrote:


The antenna is a folded dipole cut for 13 meters connected to the radio
with coax.

I evaluated two stations on this band. One had locally generated noise
interference and the other did not.

I tried a repeat today with switching the matching transformer in and
out of the circuit and compared it to a large ferrite toroid in its
place. The coax made one turn through the toroid. The ferrite worked as
well as the transformer on the station with the local noise on it. No
difference found on the station in the clear. In addition the
transformer did not make a difference in the S meter reading either.

It takes me several minutes to change the transformer in or out and we
had a minor geomagnetic storm yesterday so conditions changing must have
been what I saw as a performance difference.

Today conditions are more stable and I switched the transformer and / or
toroid choke in and out several times averaging the results.

So it looks like the only benefit of the transformer was isolation it
provided on the folded dipole.