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Old March 7th 07, 04:12 AM posted to rec.radio.amateur.moderated
Bill Horne, W1AC Bill Horne, W1AC is offline
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First recorded activity by RadioBanter: Feb 2007
Posts: 19
Default Tube equipment question

wrote:
[snip]
The "unbalanced tuner followed by a balun" idea is clearly
one where "newer" wasn't necessarily "better" in all cases.
Yet it became very popular because it usually worked.
But in many cases the balanced line was actually
doing a lot of radiating and there was considerable loss in the
system.

Back in 1990, AG6K came up with an answer to the
shortcomings of that method. He put a 1:1 balun between the
rig and a simple balanced tuner, so the balun only has to
deal with a pure 50 ohm load once the tuner is adjusted.
Although AG6K favors baluns made from coax wound on
PVC pipe, other forms of balun such as ferrite-bead and
wound-toroid can be used if preferred.

[snip]

I'm not sure a "balanced" tuner is required. I have an off-center-fed
dipole I use with 600 ohm ladder line, and I'd like to try it with an
Ultimate Transmatch. If I put AG6K's coax balun on the input and isolate
the chasis from ground, wouldn't that achieve the same result?

Bill


--
73,

Bill W1AC

(Remove "73" and change top level domain for direct replies)