[TowerTalk] Feeding a multi band loop (cloud burner) with balanced line
Mon, 17 May 1999 17:00:51 PDT
I just upgraded my 80 meter full wave horizontal loop to use balanced line
(450 ohm) for the first 50 feet then coax (bury-flex) for the last 20. At
the transition I'm using a w2du 1:1 balun. I expected this to be a upgrade
for the system, less loss etc, but my tuners now only find a match only on
15 meters. When the antenna was feed with all coax I could get a good match
on all bands. Even on 15 I seem to only get to about 3:1. I have tried
both a LDG tuner and the internal tuner in a TS-570, they both just give up
right away. I put a Autek RF-1 on it and it just reads "H" which I think is
> 20:1. With coax I never saw > 10:1.
I'm suspicious of the balun, I went with a 1:1 because I figured at some
freq's the impedance would already be very low. But now I'm wondering if
anyone else have tried this configuration or is a 4:1 balun the answer. Or
maybe the balun is bad, if while the RF-1 is connected I ground one side of
the balun, the swr drops ? I don't know why I even tried this test, but I've
tried about everything.
Any help would be great, over all with a ICE balanced arrestor, ladder line,
loc, knife switch and balun this was about 200 dollar "upgrade".
Thanks in Advance
Jim Apple (WB1DOG)
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