I talked with Dynon about the MP readings moving up a couple of inches when the PTT was pressed. They mentioned this was something new... We agreed to move the aircraft outside the hanger (Garage) and try it again. Although it helped some the MP still jumped up an inch.
The aircraft does not have the wings mounted at this time. I noticed that the capacitance fuel level BNC connectors were hanging free about 2 feet from the transmitting attennas, and were not grounded. I thought these could be acting as antennas and allow feedback to the EMS module. I basically connected a jumper from the outer BNC to the airframe, and to my surprise the MP did not move when the PTT was activated. problem solved.
Lessons Learned: I am old school... so these all electric aircraft, and sensitvity of the electronic sensors any open wires / grounds feeding the EMS can pick up the smallest of electronic noise. Grounds take up a whole new meaning in "ALL" electric glass cockpits.
