A mysterious problem, help please
Funny one this,
Instructing yesterday, radio on 123.6, change frequency to transmit on 129.725 and as I transmit low rotor horn and light come on. No yaw and RPM needle stable.
Transmit again, same thing. Try different freqencies and same happens down to 124 or so up to 132.
Pull Low rotor CB before transmitting and no horn, pop the CB in immediately after transmitting, to continue flight.
Back on the ground no sign of problem on any frequency, then later on another flight in the circuit on 122.2 same thing happens.
Ideas folks?