"Owen Duffy" wrote in message
...
On Sat, 08 Oct 2005 06:26:31 GMT, "Lee"
wrote:

To continue the saga......

I fitted a variable capacitor to my 10 foot circumference 1mtr loop and
am
able to tune 80 to almost 15 meters...works well..but.........

How to fit a motor drive !!!.....there seems to be nowhere to acquire
cogs,
pulleys or gear sets....no model shops around that carries components,
that
i`ve googled for anyway..(now when i were a lad! ).... ;-)

Can you imagine how fast that electric motor turns the capacitor, even
with
reduced voltage???..you have to be quick i can tell you or you miss the
sweet spot heh,heh....

Seriously, any ideas to slow the tuning rate will be most welcome .

Assuming it is a permag motor, reduce the motor voltage... add a
current limited driver to limit the torque, an electronic shear pin if
you like... except it doesn't shear.

I am assuming that you are trying to tune the reactance out, to
achieve an acceptable VSWR on the line to the ATU/transceiver. Have
you considered automating the capacitor drive. You could build a phase
detector (between V and I at the antenna input) as a sensor to control
the motor drive.

Doesn`t work with a magloop!!!.....thanks anyway.

Lee.....G6ZSG.....


Owen
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