[TowerTalk] rotor @ 200m distance

[David Gilbert]

I like using this website for that sort of thing.

http://www.calculator.net/voltage-drop-calculator.html

Dave   AB7E


On 10/14/2017 10:08 AM, Jim Brown wrote:
> 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
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>