[TowerTalk] Power Over Coax

[Kipton Moravec]

I am aware that people use coax for DC power to power electronics.

I have a 12V 1A (max) motor. It will be variable speed by using PWM
(Pulse Width Modulation)

I have an engineer that says I can power the motor over the coax. He
says no problem -- people power over coax all the time. I do not believe
him. I can believe it can work for low power stuff, like the LNA for my
GPS antenna. But a LNA does not generate the same level of noise a motor
does. 

My concern is that a motor is electrically very noisy. Sparks occur as
the brushes cross the rotor. This coupled with the inductance of a 1A
motor and a long cable can produce some serious noise.

I do not think one can filter it (within a 4 square inches of board
space) to the point that I would be willing to hook up an HF receiver
and see if it blows out the front end. 

I thought I would ask the collective wisdom of the TowerTalk people.
Do you folks think powering this motor over the same coax your HF radio
is on is doable?

Kip

-- 
Kipton Moravec AE5IB .- . ..... .. -...

"Always do right; this will gratify some people and astonish the rest."
--Mark Twain