An interesting observation is that Roy Lewallen, noted QRP author and
Antenna program author, has now on his web site, a retraction of his former
suggestion that it was better to put the balun at the input of a Tee type
tuner.
His revised calculations say there is no difference in placement. However,
I thought the rational was to move the balun to a lower voltage condition of
the 50 ohm side of the tuner, vs. placing it in the high voltage field?
I have used a variety of Tee circuit tuners, and have not observed heating
in any of the baluns at 100 watts or less. The use of the external baluns
does automatically allow more inductance in the balun which might be of use
with some antennas. Anyway, it was an interesting observation to see
improved match with an external balun, and the internal one out of the
circuit. Gave the flattest response over 20m band with our big loop, and
allowed one tuner setting to suffice for whole band.
-Stuart
K5KVH
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