petrus

So what kind of things has everyone done to abate noise? I have S9 ignition noise on my IC7000 in my 2008 Unlimited. 40m is the worst band. AM is pretty much useless with the engine running. I've bonded the exhaust to the frame in 3 places with braided ground strap, and that might have helped a little, but probably wasn't worth the effort. Anyone have luck with ferrite beads on the ignition wires? Anything else you've tried?

Thanks and 73,
pete AA8L

Jeff

I installed a Ferrite on the power lead to the radio that helped make 40m better. Hve not tried ignition.

N4XGI

AK4Dave

I have not installed an HF rig in my JK yet, and by the sounds of it, it's not something I'm looking forward to. I remember the fuel pump on an old Dakota I had made so much noise it was unbearable.

As you probably already know you need to determine if the noise is being picked up by the antenna, or is coming through the powerline, or God forbid.....BOTH No fun at all. If you determine it is on the powerline, as already mentioned, ferrite beads can work wonders. They are cheap, and it's not a bad idea to start throwing them on everywhere you think could be suspect. I remember you can also buy an actual 12v automotive noise "choke" to run on your radio's powerline. I think I bought one years ago at Rat Shack. I may still have it so I'll look for it and let you know.

With all the plastic in vehicles nowadays, it's never a bad idea to start adding grounding straps all over the vehicle. From everything I've gathered over the years, you can never have enough. Sometimes even moving the ground to a different location may help.

If you find the antenna is picking up rf noise from the Jeep, then good luck. I've even known some HAMS to actually build a grounded metal box around the noise generator and get some results. Or wrap a few grounding straps around it which is essentially "almost" doing the same thing.

Sorry, but at this time, without having an HF rig in my Jeep myself and not being exposed to the noise, this is about the most I can say on the subject. I know it can drive a guy crazy, but stick with it. All it takes sometimes is one extra ferrite bead, or that one ground strap placed in the right place, and problem solved.

Oh, I just remembered a good source for beads and rf shield "kits", Check them out. https://www.amidoncorp.com/

73 & Good Luck...
Dave / wl7cmg

PS.....Do the Icom mobiles have noise blankers? If so, I take it they won't take out the noise? Probably not, as even some of the best base station noise blankers won't take out all noise sources. 73

petrus

Jeff: ferrite on the power lead sounds promising, thanks!

Dave: Yeah, the noise blanker on the IC7000 is actually pretty good, just need to do better. To be more specific, I should have said "S9 without the noise blanker, at highway speed" in the original post.

pete AA8L

motrac45

Well I not a ham, but I have worked for Motorola for 30 years. I measured my 07 4 door with a fluke meter it was bouncing between 20-30 mv AC. If you have a fluke meter or an AC scope you should measure about the same. If you measure about 150 or more mv AC, then you need to buy a motor noise suppression kit, which is a large capasitor, that will filter, reduce, the AC componet from your charging system.

N2MWL

Did you ever determine whether the antenna was picking up your noise or the power lines.....I hesitate to put an HF rig in the Unlimited myself.....

73
Mike
N2MWL

Jeff

Tracking noise down
determine if the noise is conducted or radiated.
Conducted noise will get into the radio via the wiring. Here is how to check.
1.Take antenna off of radio.
2. Turn all accessories off.
3. start engine and turn on radio. Select AM mode, Noise Blanker off.
4. Any noise? Turn AC on and off. Now you know.
5. Turn engine off. Now turn accessories on and off one at a time and listen for noise. Now you know which ones conduct.
You can try Amidon Ferrites Mix 31 ( for 0-50MHZ)on the leads of the noise sources you have found. Or try shielding the leads.
Radiated noise gets in via the antenna. Here is how to check.
1. Put antenna back on radio.
2. Turn on Radio, AM mode, Noise Blanker off.
3. Make a note of the noise level.
4. Start the engine.
5. Poping noise that varies with RPM? ignition wires. I have some of this. I am thinking of buying some braid and slipping over each wire
6. Wining noise that varies with RPM? Alternator.
7. Try all of the accessories one at a time again. Make a note of which ones radiate. One noise may mask another. Work on one at a time.
The radiated noise I am trying to solve on my JK happens as I am engaging the clutch. Once it is engaged the noise is gone.

N2MWL

Just bumping this to the top in case someone might have some new info.....

Jeff

No new info. However I did write Jeep a letter and asked for technical assistance on solving the noise issues. I did this a few years back with a GMC truck and GM sent me a manual they used to install Communications radios for Federal Park agents, and one of the Engineers contacted me. They were very helpful. We tracked the noise down to the computer. I put a flat ferrite on the ribbon cable and fixed it.

We will see what Jeep comes up with.

N4XGI

AK4Dave

As Jeff has shown....FERRITES ARE YOUR FRIENDS...!!!! Have you checked with Amidon yet about their kits? They are a real good source. I also still think you can buy wrap around ferrites still from Rat Shack.