| Some sources have outputs for both a turn-on lead and an antenna lead. You'll want one which only sends a + signal to the antenna lead when the radio is on. Typically such sources have two different wires, a blue lead and a blue with white stripe lead. I'm not aware of any sources with such a feature but I'm sure if you spoke to the good people at Alpine, Eclipse, Pioneer, et al. they might be able to send you in the right direction. There's a way to dismantle the source and make the turn-on lead function the way you want it to but that's beyond me.
----- I hate winter. |