[TowerTalk] Rotor for Long Cable Run
Jim Brown
jim at audiosystemsgroup.com
Sun May 10 22:26:02 PDT 2009
On Sun, 10 May 2009 20:18:48 -0400, john at kk9a.com wrote:
>I would be more concerned about whether the SteppIR will work properly
>with that long of a run.
Hi John,
Thanks. I'm concerned too. FWIW, I am disgusted with the mfrs of all of these
products, including SteppIR, for not publishing specifications for what is
essentially a simple Ohm's law problem that all of their customers need to
solve when doing due diligence. It is a very simple matter to specify the
currents involved, the output of the controller, any adjustment that is built
into the controller, and the IR drop that can be tolerated. Starting current?
Fine. Specify it.
I'm told that SteppIR cable is paired, but there's no indication of which
conductors are pairs. In fact, if I wanted to order my own #18 rather than use
their #22, I wouldn't know that from reading their documentation. BTW -- if
their cable is a foil shield with drain wire, that drain wire can couple RF
shield current onto the signal pair by a mechanism called Shield-Current-
Induced Noise.
Ohms Law still works. Give us the data on the product so we can use it!
73,
Jim Brown K9YC
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