>From: Jim Dolson <dolsonj@ix.netcom.com>
>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? jim wb8zbd
Hi Jim, if one has an SWR of 1:1 on the balanced feedline, one
can simply use a balun at the unbalanced tuner output, 6:1 for
300 ohm line and 9:1 for 450 ohm line. My 4:1 balun never sees
anything except a perfectly resistive 200 ohms because my tuning
function is between the balun and the feedline.
If one has high SWRs on the balanced feedline, one should only
ever use a 1:1 choke balun at the unbalanced tuner output because
4:1, 6:1, and 9:1 baluns are designed to work only around their
design resistance with neglible reactance. In general, with an
unbalanced tuner and balanced feedline, one should use a 1:1
choke balun and feed the feedline at a current maximum point.
The BASIC program that I posted a few days ago gives the
approximate location of the current maximum points.
73, Cecil, W6RCA, OOTC
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