Hi Jim:
I surely enjoyed the visit with you at Ft Smith. Knowing you would be
bunking with Clif, I
had packed the schematic of the Z-Match article from Jan 2003 QST, with the
express purpose
of pouncing on you for an explanation of its "inner workins". Even tho I
had info from Charlie
Lofgren that briefly passed over the fact that we were tuning TWO tank
circuits at the same
time, it was not soaking into my brain. I was simply seeing ONE winding,
thus ONE inductor.
It took you about two minutes max, to turn the light on, that the center
tap on that winding
was actually DOIN something. hi... For whatever reason, I simply had not
been able to get
that thing to cover 80 to 10 meters, no matter how many/few turns I put on,
nor how I
compressed/spread those turns. The problem was, I was adding/subtracting
turns on both ends
of the winding, and spreading/compressing turns from bottom to top. Once
you turned the light
on, I found that the bottom half did indeed allow tuning of the upper bands
fine, with the specified
turns, normal spacing. Compressing the upper half turns all possible, plus
adding a coupla turns then
allowed tuning down thru 80 meters.
Had I simply started adding turns to the top end of the winding, I would
have had it working in
short order, but would not have understood how it was working at
all. Thanks to you, I THINK
I understand a bit more about what is going on with it. At any rate, I
have a nice lil tuner that
works pretty much "as advertised".
Hope to see you at Hamcom in Dallas, if you make that one.
"73" Dub
J. W. (Dub) Thornton WA5YFY
Minco, OK.
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