If your PTT switch causes your EGTs digits to go crazy, contact Dynon. I just sent my EMS-220 into Dynon for the factory CB mod to hopefully take care of this problem.
David Heal - Windsor, CA (near Santa Rosa)
EAA #23982 (circa 1965) - EAA Technical Counselor and Flight Advisor; CFI - A&I
RV-12 E-LSA #120496 (SV w/ AP and ADS-B 2020) - N124DH flying since March 2014 - 1,170+ hours (as of May 2022)!
through June 2023.