Pitot Heat and GMU22, Interfere as suspected
It was a long time ago that I fretted that this would be a problem. Ran a dedicated twisted pair out to the pitot heater outboard left wing, hoping that the pitot heater would not interfere with the magnetometer. I did ground the return wire at the fuselage and not back at the main ship ground.
Nav and strobes no problem for the magnetometer. But the pitot heater causes a 220% anomaly on the G3X interference test. It is intermittent, I suppose depending on how on/off the pitot heater control is. 90 percent of the time it works all the time (watched Anchorman this week). But that other 10 percent or less of the time it is awful.
I have a Dynon heater with controller, since that is what I planned for initially; don't know if the operating characteristics of the Garmin are the same. The Dynon seems to be very on/off and not linear.
Next step will be to run a wire to the main ship ground and see if that makes much of a difference; I suppose a lot of current right at the fuselage/wing junction could make a difference; not sure.
In operation inflight what would you see on the displays when that pitot causes interference? GTN650, G5 and dual G3X; perhaps they would just default to GPS heading? An alarm every time?
Does the Garmin pitot heat controller have a different operating characteristic?
Would a straight heater without a controller have a different characteristic?
Ser 104142, RV-14A
Ready to gas it up!