Instruction manual

lfaRadio Ltd. 2002-2008

www.alfaspid.com www.hy-gain.com RAK1 Manual Page 17

Page 17 of 21

lfaSpid Rotator RAK1 http://Alfaspid.com http://www.hy-gain.com

lfaRadio Ltd. 2002-2008

Using the

lfaSpid Rotator with LONG Cable Distances

By VE6JY

Since the motor uses relatively low voltage DC, a combination of long cable

runs and/or thinner than required cable may reduce the voltage at the motor to an

unacceptably low value. It may turn in warm weather or light winds but the power will

not be available to rotate under more severe conditions.

While it is easy to say just use a heavier cable, this may be costly, impractical

or both. I have one tower that is over 1700 feet (approx 500 meters away) and

running large cable out there would be very expensive.

My solution is to use this rotator controller's output voltage to control another

set of relays that will feed a higher voltage DC to the motor. In the above-mentioned

example, I find a voltage between 60 to 80 volts gave suitable performance. This is a

pretty extreme case but it illustrates the versatility of this design. The external DC

supply voltage needed will vary depending on the DC voltage rating of your motor, the

cable size and length of the run. Typically 36 to 50 volts at 3-5 amps should be quite

adequate. These DC motors are quite tolerant on their voltage ratings.

Relay Board Schematic