[TowerTalk] SteppIR problem...size wires? ala KH6

[Jim Brown]

On Mon, 18 Jun 2007 14:37:50 -0700, Jim Lux wrote:

>Actually.. I think it would be better to make the "power handling" 
>wires the short ones, and the "information handling wires" (the RS232 
>connection) the long one.   Rather than try and develop and build 8 
>drivers (2 coils for each of 4 steppers), just buy an off the shelf 
>long distance serial connection.

Jim, you may have hit the nail square on the head (as usual)!  If the 
StepIR will work that way from a user interface point of view (that is, if 
the user controls aren't on the box that you want to move to the base of 
the tower), that makes a lot of sense. RS232 will easily go several 
hundred feet if low capacitance twisted pair (like CAT5) is used for each 
circuit and the wiring avoids pin 1 problems and hum loops. Follow the 
instructions in my RFI Tutorial, and be careful NOT "ground" the RS232 
signal at more than one point. A good way to do this is to keep it off of 
ground at the tower, and let it get its power from the shack. 

http://audiosystemsgroup.com/RFI-Ham.pdf

If you want to go further, B&B Electronics (google to find them) has good 
interfaces at moderate cost that convert the RS232 signal to a balanced 
one. 

73,

Jim Brown K9YC