Radio transmit despite not being turned on

[Flagrum]

The VHF AM radio transmits although still turned off.

 

I had a small JTAC test mission and contacted Axeman at the correct frequency. Just in that moment I remembered that I had to turn on the radio manuall - despite "starting hot". The moment I switched it on, I could just hear the ending of Axeman's reply. So he could hear me while the radio was off (while I could not hear him until I turned it on).