On 2007-09-26, Richard Clark (67.168.144.41) wrote in
message


I have also done the following experiment: Instead of the commercial
"magnetic balun" I was using, I have now rolled my own 1:9 unun. The
main difference with the MLB is that the unun has isolated windings.
The primary is grounded to the earth rods, the secondary is grounded
via the receiver. I thought this was a better solution with regard to
ground loops.

Not really - it may cast the problem into a different coupling
mechanism. You still have capacitive coupling and you want to ground
the smallest signal end (the antenna), not the load end (the
receiver).


Ehrm... that's exactly what I did. For a SWL, the antenna end is the
primary end :0)



However, it sounds like it didn't make a substantial difference, or
any difference (seeing as you would have mentioned performance).

QRM levels were the same, very low to totally absent. Signal quality/
performance seems to be the same.


I've read (and tried) all the "expert" SWLing opinions of what pass
for BalUns (even professionals rarely get it right) and experience
still shows a tuner performs better - unless, of course, you really
have a sloppy installation (no choking, poor grounds, poor balance,
running lines past noise sources, the usual stuff).

There is indeed a lot of confusing stuff about baluns circulating in
magazines and on the internet. Is thought it was only possible to use a
antenna tuner at the receiver end when the antenna wire is directly
connected to the tuner, ( that is: without using a coax line)
Right or wrong?

73's - Dirk