Magnetic Loop Antenna

[dcselec]

Hi
I am building a loop antenna to use on the 10 meter band TX/RX
the loop I am fine with and the loop is tuned using a variable capacitor
It needs a DC motor to turn the cap at high speed low speed and pulse I
was thinking of using a stepper motor with a controller/driver pc based. The motor
will be 10 meters away from the controller will this be ok or any better ideas
worried about the cable run to the motor as most aplications the motor is normally
only a short distance from the controller/driver ??
Thanks Dave

 

[crutschow]

That should be no problem with that distance as long as the wire size is sufficient so that its resistance doesn't cause a significant voltage drop at the motor's operating current.

 

[dcselec]

Thanks crutschow I am planning on using a 12 volt motor and some
good cable will have a look round now and order some bits

Dave

 

[g3vbv]

I am using a controller circuit I found on the internet and the motor is a 4-15V DC one from Maplin.co.uk. It has a 3000:1 reduction gear (NO1BQ) which they no longer stock but there is a NO4BQ. My motor looks exactly like their WC70M which is only 10:1. Perhaps you can find a suitable motor elsewhere if 10:1 won't do.

I use a DPDT momentary switch for forward/reverse. The potentiometer sets the speed from very fast to stop.

My magnetic loop (8' diameter 22mm copper tube with 45 deg. elbows) uses a large vacuum capacitor and it's for 80m/40m.
The previous loop was 13' diameter 28mm copper tube blew down in high winds and smashed the vacuum capacitor but I'm planning to erect it again. All my 80m contacts between UK and USA were made with this loop.

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