Amp Power Source

Yeh, but again, find out if the "main" power lead draws any current with the trigger (radio) off. If you are going to switch the main anyway, then I'd agree a continuous duty solenoid is likely what you want. The "right" way would be to determine how much current the thing(s's's's's) draw at full output. Then buy a relay rated for at least that much. Go overboard. LOL