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Re: Any info about making air variable capacitors, and magnetic loops?


M Garza
 

When I built my 10M loop, I used this calculator:

I liked this calculator, since it provides approximate voltages the cap will see and I could play with the figures to see the outcome.
Depending on the rf power, you could see several thousand volts at the cap.? They also have a capacitor calculator, you could use that to design a cap.

You could use coax capacitors, high voltage caps, air variables, trombone style, or vacuum variables, just to name a few.? Search you tube, there are a ton of examples.

I am feeding the loop with a toroid and 3 turns of #12 wire.? Similar to VK6CS in these videos:



To connect a motor to the cap, use some kind of insulated shaft coupler to keep the high voltage off the motor.? Make sure to bypass the motor terminals with a 0.1uf cap to try and keep the rf out of the motor.? I would suggest a geared motor, ?something with a low RPM.? You could vary the voltage to the motor, to control tuning speed.

Hope that helped some.

Marco - KG5PRT?

On Jun 21, 2017 1:17 AM, "John Smith via Groups.Io" <johnlinux77=[email protected]> wrote:
I have some plans and ideas, but thought I should consult with the smartest group of people I know. Can I use zinc plated hardware with aluminum roof flashing? How to attach a arduino stepper motor to caps rotor shaft? Cheat on the loop by covering a hula hoop with aluminum foil? And I still need a antenna tuner after tuning the cap for resonance, Right?
Have any mag loop calculators, or instruction sites. Hopefully I will find more than I've seen so far.? Good instructional homebrew videos on youtube are great too

Thanks in advance de KG5KYJ

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