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Re: Terry's remote tuning idea
Terry Fritz wrote:
__________________________________________________________________________
One of my new projects (one of a zillion I have planned for the cold
months ;-)) is to make a remote primary tuning device.
[snip]
I will have an "extra" MMC with four stings. They will have a
value of 0.5, 1.0, 2.0, and 4.0nF (could be other values too). This
device
will be parallel with the regular primary cap. By selecting the strings
in
a binary fashion, I can select from 0nF to 7.5nF of additional
capacitance
in 0.5nF steps.
[snip]
Any help, ideas, etc. are welcome. It would really be cool to adjust
the
gap and primary tuning remotely from simple switches.
__________________________________________________________________________
Hi Terry,
I used a 'Litz Wire' primary tuner on my 30kVA coil,
which works quite well. It does not require sliding
or moving electrical contacts. The final half-turn
of the primary winding consists of a link of heavy
Litz cable, made up by weaving eighteen #8AWG wires
connected in parallel. This cable is slung directly
under the primary coilform, and effectively adds or
subtracts up to one-half of a turn, depending how it
is positioned. A motorized linear screw travel allows
the Litz cable to be adjusted remotely.
I did a writeup on it in TCBA Vol 10 #2, if you have
a copy of that one.
--
-GL
www.lod-dot-org