Static on GMRS Radio, both handheld AND mounted.

I did search this forum AND Google however have not found my particular issue.

I have terrible static on my GMRS radios. I have a Midland MXT 400 that is hardwired into the fuse box (non-switched power) and has a chassis ground. I also have a Midland handheld GMRS. Both have terrible static when the truck is running or if I remove the handheld from the interior. Obviously I have interference from something in the truck. I do have an aftermarket radio amplifier that is getting power straight from the battery and on a chassis ground, not a frame ground. Static is present with or without the truck radio(stereo) on. Turn off the truck and the static goes away. I have even swapped out the MTX 400 with a MTX 275, same issue. I have not done anymore troubleshooting other than what is stated. What is the most likely culprit? Amplifier power cable? (4ga OFC from battery to amp in the back seat) Ground cables? Help. - 2021 Tacoma TRD Sport

 

Have you tried running your positive for your midland straight to the battery?

What do you mean static even when radios are off? Do you mean even when stereo is off, there is static from your midland units?

 

I have not tried running the power to the battery as yet.

Correct, when the truck radio is off, not the GMRS radios, there is static on the GMRS.

 

Try going straight to the battery first on the radio before you do anything else. You can pull the fuse for your aftermarket amp to see if somehow that's the culprit but if it's a name brand amp it should be reasonably shielded from producing interference.

 

Ok, I’m gonna go straight to the battery from the GMRS radio and check. BUT, that still does not explain my hand held GMRS having the same static. By the way, aftermarket amp is a 2 year old Kicker amp. It “should” be good.

 

Look into ferrite cores. Also check out the HAM radio thread here on TW. HAMs are experienced troubleshooting these types of things.

 

You have any aftermarket LED lights installed? Or any other electronics that could contribute to interference?

 

have a read of this massive thread
https://www.tacomaworld.com/threads/fuel-pump-rfi-ham-radio-related.735738/

it's a nightmare - I've given up mounting an external antenna for a simple scanner

on page 9 is a real doozy quote

“I have been doing HF CW ham radio contests for more than 25 years.

I have operated the Florida QSO party mobile for many years. For several years I never had a problem making 2000 Qs in that contest over the weekend. That was in my 2004 taco. Then I traded the 2004 in and got a 2017.

It is the worst RFI spewer I've ever had. I tried to eliminate it for a few years but finally gave up. Last time I did the FQP me and my op partner quit half way. Noise is S7 on HF straight into antenna whenever the truck is running. Torroids, separate battery, grounding everything, grounding nothing..... nothing worked. I tried several rigs, 590, 7000. I use ham sticks mounted on a massive 2'x3' Al plate bolted to the roof rack on my topper. LMR coax. I ran counterpoise wires around the roof rack. When the truck is off, it's a pileup buster. When it's running, I can't hear shit unless it's S7 or more.

I'll be following for further developments. I'm surprised there aren't more complaints about how bad this problem is. “
​