Have a mounted standard horizon vhf. Powers up fine, was getting no reception. Replaced antenna wire, new antenna. Same issue. However, when I loosen the connection on the back of the radio to where the coupler isn't touching the threads, it works perfectly. Soon as the coupler touches the threads the reception goes out. I tried a new radio, same issue. Is this a ground issue with the antenna? I'm stumped

Maybe a bad cable coax connection. If you have a multimeter you can take the antenna off and radio off, so the wire is not connected on either end, and measure resistance/ohms from the center pin to the threaded barrel. Well here is a detailed link probably better than I can write.

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Just for clarity
The antenna and cable has been replaced, and when the new connector was installed on the cable the shield ground is not touching the center conductor.

This happened with both new and old antenna?

If the above is true then the problem is in the cable connector in the radio. Check the connector on the radio and it good, open it up and check wiring to the connector

Yes. I replaced the antenna and the cable. I also thought it was the connector on the radio itself so I got a new radio as well. Same problem. Works fine until I go to tighten connection at radio. Soon as contact is made with the threads it cuts out. If the wire is in the hole unfastened it works. I put a stubby antenna on the deck connection instead of a larger whip style, don't need large antenna. Maybe the issue is on the deck side, I dunno

What do you mean by it cuts out?
you hear static and it stops or something else

for example , I'll put on noaa channel with cable fully connected and its just silent,, no static or anything. When I unscrew the cable to where the coupler isn't touching the threads, I get crystal clear reception

did you install the coax connector? Did you do any testing with a multimeter?

I did install it. Haven't had any time to test on it with the multimeter yet. When I'm off again I'll be back at it. I did read through that article you posted. Thanks for putting that up.

Sounds like a ground problem. Did you install a chassis ground on the VHF? This is not the +/- power wires.... What did Standard Horizon say??

I am an FCC licensed general radio operator. Used to work for Motorola. I have installed tons of coax connectors, and messed up a few. All it takes is one strand out of place. Make sure the foil is also not touching the inner pin. The ground plane should not cause this issue, just poor transmit and receive quality if not large enough. You could by a cheap watt meter and check your whole system.

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