Hi, Jim--
>>I use balanced feedlines exclusively with balanced
tuners. Is it possible to use an unbalanced tuner (LDG
"group buy" QRP tuner) with a balanced feedline?
<<
The expression "balanced tuners" is kind of intriguing. I presume
you mean tuners that offer connection for balanced feedline. They do
that by including a balun, and there is no practical difference
between having the balun inside the tuner box or outside it. If you
look inside a "balanced tuner" you will almost always find (in my
experience) the hot side of the balun is in parallel with the coax
output (as is the usual single-wire antenna connection). In fact,
fwiw, I have a 1KW tuner with a five position switch which includes a
position for "balanced" but in fact it switches to another coax
connector on that back, and has no balun.
An advantage of an external balun is that you can run coax outside
and put the balun outside your shack. This can reduce or eliminate
rfi problems (though perhaps generating new ones on other bands).
To be more specific, I run an "all band" doublet fed with 450 ohm
ladder line. The ladder line goes to a balun on one of the
antenna connections of a 6x6 coax switch on the output of the AT-11,
and it works fine.
73
Marshall Emm
AA0XI/VK5FN
aa0xi@mtechnologies.com
http://www.mtechnologies.com/mthome
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