"John Kirk, VE6XT wrote:
>I once read of a really cool idea to use a single-ended tuner on on
>balanced line:
>Ground the rig.
>Don't ground the tuner.
>Install a bead balun between the rig and the tuner. These are the ones
>made by stringing multiple toroids over a piece of coax.
>The idea being that, coming off a balanced feed, half of your returned RF
>would love to visit you via the ground. Because of the choke bead balun,
>it can't so, goes up the spout for another shot at the antenna.
>I haven't tried it, but it sounds doable. The case of your tuner would be
>hot with RF, but most oof us live with that now, due to suboptimal grounds
>anyway.
In other words, let the tuner float at some rf potential and do its
job.
I first saw this idea in a little piece by Zack Lau in QST about 6 or 7 yrs
ago.
If you are trying to do this with the AT-11 automatic tuner, you will
also have
to rf-isolate the power leads (both + and "ground") with some rf chokes.
Should work just fine. Let the tuner "float". I wouldn't recommend this
at
QRO levels, however. You might get an rf burn when you reached to tune
the tuner! Also note that you might get some funny hand capacitance
effects
when you tune, so an automatic tuner might have an advantage!
Dan Winkler N7IVR SEattle WA
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