Is there anything wrong with using an RG6 cable as sensor wire? Its shielded, and its a thick wire..
When it's used for DC or pulsed DC it's no longer considered shielded as you're now using the outer shield as a current carrying part of the circuit.
One way of looking at it is in the audio world pros use shielded twisted pair and XLR connectors which is far superior to using RCA style coaxial cabling for induced noise rejection.
In your home stereo or audio rack if you lay a coax cable next to an AC power cord. Such as a turntable cable.
Not cool and you get a ton of induced AC hum. Using shielded twisted pair cable, chances of getting that hum is vastly reduced.
Plus you now have a balanced (as opposed to unbalanced) system where equal current is carried on each wire.
Or. As I grabbed of the 'net:
"Connecting that unbalanced, grounded transmission line (coaxial cable) directly to a balanced load can result in all kinds of problems, such as currents flowing back down the shield to the source."
Not saying you shouldn't or can't use it. But if it's stray noise rejection in the pulsed encoder signal to your diseqc controller you're seeking. A twisted pair or twisted 3 conductor cable with outer shield is the only way to go.
Then we could get into impedance and stuff that would reflect or cancel out pulses on the way down the coax.
I'd run out and have them spin the carousel at Home Depot personally.