So, I'm relatively new to all this; and I've gotten an ICOM IC-7100 on sale, which looks like an excellent transceiver … unfortunately, this very specific line shows up in the manual:
The transceiver may not receive well on some frequencies when installed in a hybrid vehicle, or any type of electric vehicle (fuel cell vehicle). This is because vehicle’s electric components such as the inverter system generate a lot of electric noise.
To boot, reading other questions on this site, I came across this excellent news:
… In the worst case, your cigarette lighter may be wired for "chassis ground return", where [the] current is not being returned through a copper ground wire, but through the car's steel chassis. This is OK for stuff like an AM/FM radio or the cabin lighting, but that same resistance equates to a higher voltage drop with your [radio], which can distort your output signal or even cause devices to sense an "undervolt" condition and shut down.
Taking a look under the hood, so to speak, this is precisely the situation in my car … except not for a cigarette-lighter port, rather literally for the entire car — of the 50A primary-12V “battery terminals” you're supposed to jump her with, the negative is simply a post on the chassis:
So, how should I best wire up my transceiver? (I've tried to google up some sort of ‘line noise filter’ for DC power, but 1. they all seem like extremely sketchy products, 2. most of them have lots of ‘this did nothing for me’ reviews, and 3. most of them are rated for small amperages.)