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If you are new to radio, hopefully this will be helpful information for getting the most out of your radio. Normally, when I install a radio in one of my vehicles, I cut off all the connectors and run my own lines from the battery to the radio. Occasionally, my GMRS radio gets moves between 2 vehicles, so I left the factory T connector on it. Turns out, that was a big mistake for performance. I had a few people tell me that my signal would be very good for a second and then rapidly drop to a weak signal. I ran a field strength test and the voltage would peak at 77.5 V/m on initial key, and almost instantly drop to 65.7 V/m. That is a huge drop. Knowing what to look for, I measured the power from the battery on the cold side of the T connector and it was 14.0v while on stand-by. However, when I key up, the voltage dropped to 12.4v. A couple of times, it dropped to 12.1v. On the hot side of the connector, there was only 0.25v drop on key-up. I cut the T connector off and soldered in some Power Pole connectors, which have more surface area and much higher spring tension. Now, I only have 0.25v drop on the input of the radio and my field strength is holding steady at 77.5 V/m while transmitting. To give you an idea of how much drop that is in usable power, it is the equivalent of changing your antenna feed from about 37 watts to 50 watts (assuming an antenna with no gain and 100% antenna efficiency). So, if you want to get the most out of your radio, ditch your glass fuses (weak squeeze connector) for a blade fuse and replace your factory T connector with either a fully soldered connection or a high quality Power Pole style connector. Note: I could resolve the 0.25v drop if I run a larger diameter power and ground cables... but it's not worth the effort for my application. Hope this helps.

Oh, wow... that is a huge difference. Basically everything is grounded separately. I didn't think it would be a ground loop after discovering is coming in over the antenna like recieved signals, not over the power lines. Also I had a battery go tango uniform while winching. I figured I stressed my alternator. I really think it's either this specific installation or the radio. I have had 3 other am hf radios in it, including a current dedicated 10m am rig currently installed, and it doesn't happen on any other radio.

Wow! That looks great and is one heck of a deal! Congrats! Looking forward to seeing the new thread. It was based on signal reports from other stations. As soon as I got the reports, since the radio was nice and cool, I automatically assumed line voltage drop would be the most likely problem. The next thing I would have looked for was SWR (bad antenna ground, etc.). Going back a bit more than 20 years ago, I worked in radiotelegraph. RFI is most frequently caused by either proximity to the antenna being too close, bad RF shielding on the transmission line or improper output grounding. That is not exclusive, but frequent.

An easier solution would be to just ask the neighbor what tones are being used. They could tell you if they are using the same tone for RX/TX, or if its a split tone for a repeater (Ex, 141.3 RX 67.5 TX) Some people use a split tone to prevent unauthorized access to the repeater itself.

This could very well be noise caused by PWM variable speed motor controllers in your vehicle. Try installing a 1000uF 25V electrolytic capacitor right across the motor wires of each of the offending motors. Make sure you get the pos-neg correct. Electrolytic capacitors will EXPLODE if you hook them up backwards. Also, be sure to put the capacitors as close as possible to each motor. Putting filter capacitors 5 or 6 feet down the power line will do nothing for radio noise. You might also try putting large ferrite chokes on the leads where they come out from the motor controller modules. I also do NOT recommend hooking the ground wire of your radio straight to the battery negative, or to some random point on the chassis. This just by itself can cause noise from the vehicles onboard devices. Don't listen to what the "old timers" blab about this. That sloppy installation worked in the 60s and 70s, but not on modern cars. There is always a "Common Ground" point somewhere on the car that has a lot of different circuits all grounded to that one central point, usually within a foot or two of the battery. THAT is where you should hook your radio negative wire. THAT point is where the engineers designed your car to have the minimum noise for electronic circuit returns. Also, do NOT put a fuse in the black wire in a negative-ground auto installation. Argue with me about that later if you must. The red wire can go right to the battery, BUT there is most often a good power distribution take-off point to hook that up as well, right at the end of the main positive cable. It won't corrode over time if you hook it up to the power distribution point instead of messing with the battery. (DO put a fuse in the RED wire, as close as possible to the power source.) I just don't EVER hook anything but the car itself up directly to the battery. The engineers who designed your car made it that way on purpose. AGAIN: That old garbage of "just hook it straight to the battery" is just that... garbage. It is NOT 1960 anymore, and you are NOT running a 235 inline 6 cylinder with points and a condenser.