Wow. I've tryed everything and am comming to the experts for more advice

I have an 857d installed remote with the body under the pass seat and the head on the upper windshield. Running a jetstream antenna for 2m/uhf and an opek for HF.

Pics.













I have a bad whine when the jeep is on. It doesn;t come on Right when the jeep is put in to AC but only when it is running. The wine does get worse when you throttle up but substantially more when the engine is "under load" and putting out power.

I've grounded EVERYTHING. Trunk-body-frame. Double checked with continuity meter. I even changed grounding spots x3. Radio is direct wired to battery.

I even isolated out the alternator by putting in a seperate battery and grounding that battery to frame so it was not working on the vehicle electrical system at all......

fuel pump? How do I go about fixing it if that's the cluprit?

Has my investigation skills been up to snuff so far?

 

First..........is the whine coming in on the power line or is the antenna picking it up? Have you tried disconnecting the antenna/s to see if you still hear it? If the antenna is bringing it in, and if it is the alternator, you will probably have to choke it with some ferrite beads. I take it that it's coming in while on HF...???

 

Antenna. I disconnected it and the whine is gone. It is just barely audible on the uhf/vhf side but only on AM/SSB FM is very forgiving. I also tested the fact of it maybe being in the remote speaker but plugged headphones directly into the audio out and still heard it.

So it's not a power issue.......

I tryed ferrite snap on choke on the power line for the radio. Not sure where you'd put em for the alternator.

 

Are you sure you grounded (bonded) EVERYTHING? Both front fenders. Both sides of rear fender. Hood. Tub bypassing the rubber isolators/dampeners at all 4 corners. Bumpers if aftermarket. Engine. Transmission. Doors. Transfer case.

What did you bond to? Body parts to body parts or everything to frame?

Tailgate. I saw the pic. How big is that strap? You need 3/4" or 1" braid.

You should be able to identify fuel pump noise. When you first turn the key to RUN, not START) the fuel pump will come on for a few seconds. It is the high pitched whining you hear. If you don't have a garage try a shopping center parking garage or a big empty parking lot. You just have to be quick in your observation. The fuel pump only runs for a few seconds to pressurize the system then it shuts down until the engine is running and draws fuel lowering the pressure.




k0bg.com has sound files of various noise sources. If you can match your noise to the known possible source you can home in on it quicker.

 

What type of coax is that? I don't recongize it..

 

Well I have grounded the tail gate to the tub and that's it so far. But the mount read good on continuity even checked with a long jumper up to the battery ground and it's great there. That strap it prob 1/4 inch flat strap with star washers (once again checked againts the negative terminal for continuity at both connection points.

nah it;s only after the engine is running and increases in frequency as I throttle up. but it is really noticable under load (Like passing someone or going up a hill, not as much while cruising)



Jetstream JT-C5

 

Edit.. It sounds like ignition noise.

I was never able to fully quiet all the ignition noise in the jeep. I have ignition noise of about s3/s4 w/o noise blanker (down from s9+ at one point), with noise blanker at 100 it's all but gone.

The 857d does a good job removing those consistent noises. It would be nice to run w/o NB but oh well. I bonded and bonded and bonded some more then I choked the life out of anything I could; ignition wires, alternator, starter, ECU, misc (I've removed many of the chokes as they made no improvement). I bought special low noise Ignition wires (two different brands) both were sent back as stock are quieter. Installed dual batteries with isolators, I now only run one since it made no difference. Moved or changed antennas about a half dozen times. Finally I just gave up and turned the noise blanker up. Now all is well.

I have a hard time giving up on things but chasing the noise is one game I'm happy to finally quit. I spent two years, countless hours and god knows how much money trying to get the radio perfect in the jeep. I even sold the radio at one point and gave up on HF in the jeep until the bug came back.

Today the radio works great. I just had to turn my obsessive brain off and start enjoying it. I should start a 12 step group or something..

 

But it's weird that the noise is comming downstream of the radio from the coax/antenna

 

My noise comes in via the antenna. If I put a hand held CB under the hood it noise get seriously loud when I put the antenna anywhere near the ignition cables.

 

I'm gonna try un routing the antenna coax and see if that might be the problem.......