Strange electrical interaction with the USB

Got this little annoying problem, not sure if anyone else has seen it. A cursory search yielded nothing on here.

I have a handheld CB radio that I plug into my 12v cigarette lighter for long drives. I also run android auto through the panel USB. If I ever transmit on the CB, the android auto disconnects, as if I unplugged my phone. I'm betting this would happen with carplay since the concept is that it loses the USB connection. Something tells me the spike in amperage through the 12V plug from transmitting messes with the USB port.

Is this risky for the system? Could this be bypassed or fixed? It's annoying, but I seldom really transmit. Still, curious if anyone has seen this gremlin.

 

It may not be a power issue, it may be an RF interference issue since you are using a temporary mount/install with nothing between the transmission source (coax) and the head unit. If your coax is leaky, curled up, etc it could cause what you're experiencing. You might want to give this a read: https://www.coloradofans.com/threads/ham-radio-interference-with-head-unit.420997/

 

Very interesting. I hadn't really considered this given the relatively low tx wattage (4W). But that link certainly alludes to all sorts of possibilities, including if something isn't grounded well. Much obliged!

When I get home, can plug in the radio into an external power source and see if the issue persists. If it does, that would at least rule out the cig lighter plug-in being the culprit, and would either be interference or some kind short in the antenna wiring

 

The USB from the headunit to the jack is shielded so, in theory, that can be ruled out, especially if your TX is only 4W. Ground is where I would be looking I suppose. Or coiled up extra lengths of wire.