Garmin 430 Issue

[Robb]

I am having an issue in my RV 7. When I transmit on the com Chanel I am seeing around an 8 amp draw on my ammeter and at the same time my electronic manifold pressure gauge drops slowly down to zero. I am going to take it to an avionics shop soon if I cannot figure it out. Just wondering if anyone has any ideas before I do so. Everything else works fine as far as amp draw

[AlexPeterson]

I think the fix is to not look at the MAP gauge while transmitting...

Your gauge is only a few feet from an RF transmitter - it is not uncommon for various gauges to be affected by that.

That said, I'd probably have a look at the quality of the coax terminations on the radio out line. If the terminations weren't quite right, there could be RF leakage behind the panel.

I do not recall the increase in amp draw when transmitting on my 430, but the ammeter could also be affected by the strong RF, I suppose.

[rzbill]

I believe the specs for the 430 include a 6 amp draw on the COM power circuit during transmission.