[TowerTalk] Looking for Remote Rotator Control Methods

[David Gilbert]

A possible approach for control lines is using 4/20m current loop 
modules that are cheap and readily available on Amazon.  They are low 
impedance and relatively insensitive to most noise pickup.  They can be 
made insensitive to RF by using shielded twisted pair with a few ferrite 
chokes.  They are based upon the principle that current is identical 
throughout a loop no matter how long it is, as opposed to voltage having 
a drop depending upon the resistance of the wire.

Just search for "4/20ma converter".   They come in both 
voltage-to-current and current-to-voltage versions.  Here are some 
possible examples, and although I haven't tried either of them current 
loops are long time standard in the control industry and long distances 
are common.

https://tinyurl.com/ytdhyxvu

https://tinyurl.com/5xf953xe

Just a thought.

73,
Dave   AB7E





On 2/17/2026 1:05 PM, George Collins wrote:
> Hello,
>
> Have put up a second tower that will be used just for HF antennas.  It's in
> a nice location except for one problem: it's 500 feet away from my shack.
> I'm looking for suggestions on how to deal with a very long rotator cable
> run.  There is a barn with electricity a 100 feet from the tower where a
> controller could be located.  I'm thinking that I could run light-gauge
> control wires from the shack to a controller in the barn, thus avoiding the
> large IR drop in the motor wires.  The difficulty I see with this
> approach is the long run for the position indicator wires.  I think they
> will likely pick up RF or other electrical noise.  Perhaps some type of
> buffer or line driver could be used.
>
> I would also consider just running heavy-conductor cable directly from the
> shack to the tower, if affordable cable was available.  I think I would
> still have to deal with long position-indicator lines.
>
>   Perhaps a wireless solution may be the best method, but I would probably
> need to copy someone else's design.  I am familiar with various
> microcontrollers and SBCs, but I haven't done anything programming of WiFi
> networks, etc.  I would like to use the typical Hy-Gain/CDR type controller
> and I will probably use a HAM-IV rotator, although a Yaesu rotator is a
> possibibly.  Making electrical modifications to the rotator or controller
> is not a problem.
>
> Any suggestions (other than moving the shack to the barn hi hi) will be
> very much appreciated.
>
> 73,
>
> George, KC1V
> FN31
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