I recently increased the height of the tower I shunt feed for 160 to
105'. Presently no antennas on the top only a bit of mast out the top.
The 2:1 BW is quite narrow so I decided to try to motorize one of the
caps in the omega match. First I used large air variables to get a
match. Then measured and found I had a vacuum variable that could be
used which was great because they take more "rotation" of the shaft to
change capacitance vs the air variables.
I was trying to decide what motor to use and was digging around "stuff"
I had. I found an old broken car power antenna. Opening it I found it
had a quite large motor, 12V of course. I used the large "wheel" that
the plastic cable to raise and lower the mast was wound on to adapt to
the capacitor. Using the large wheel gave me a slower rotation which
turned out to be the perfect speed. Its fast but again, with the vacuum
variable it takes more movement so it all turned out well. And, best
part, the motor and gearing was FREE!
73
Ron N4XD
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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