[TowerTalk] rotor @ 200m distance

[Jim Thomson]

Date: Sat, 14 Oct 2017 10:08:38 -0700
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] rotor @ 200m distance

On 10/14/2017 9:44 AM, Filipe Lopes wrote:
> My question is regarding the rotor, what kind of cable or how should one
> rotate the rotor at such distance? I guess the voltage drop is quite high,
> meaning the rotor will turn very very slowly or even not turn at all.

<Ohm's Law is your friend, but Yaesu's tech data is not. :) They don't 
give you a maximum permitted resistance so you must compute it. I have a 
350 ft run on my Yaesu rotator. I had to figure conductor resistance for 
their maximum recommended cable length based on its conductor size, then 
do Ohm's Law with a wire table to know what wire size to use. One 
important piece of information -- study the schematic of whatever 
rototor you are using. With the Yaesu, two conductors run the motor, the 
other three sense the position of a simple potentiometer that tells 
direction. Only the motor pair is sensitive to resistance. I ended up 
using #14 "house wire" for the motor pair and #18 for the potentiometer.

73, Jim K9YC

## heres another thought.   Use the tower as the return.  That would work if a DC
motor was used.   Works on cars, and it would work on a tower.  But in his case, the
tower is a long way away, so u still have a  V drop  from shack to base of tower. 

Jim  VE7RF