> IMHO you are much better using a ballanced tuner with an UNUN on the
> transmitter side.
http://www.w8ji.com/tuner_baluns.htm
Apparently the balun's action was never fully thought through before
articles suggesting baluns on tuner inputs were published. Everyone just
went with off-the-cuff first impressions.
Moving a balun to the tuner input works best if the tuner already did not
need a balun in the first place. :-)
There are balanced tuner tests on this page at the bottom:
http://www.w8ji.com/balun_test.htm
This shows a 1:1 current balun of good design on the tuner output is every
bit as effective as a commercial "balanced" tuner, the E.F. Johnson KW
Matchbox.
It also shows how a 4:1 "current" balun on a single core (from "Baluns and
UNUN's"), which is actually sold commercially as a balun and used in some
high-end tuners, is not a balun at all! A single core 4:1 current balun
will actually force a system into gross unbalance!
I have a friend with a high-dollar motor-driven autotuner who had incurable
RFI in his house on various bands with high power. He altered the feedline
length, moved things around, and added grounds without success. When we
looked at his tuner, it had a single core 4:1 current balun. Rewinding the
same core to a 1:1 current balun cured his problems entirely.
73 Tom
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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