Eliminating Niose on Ham Radio Jeep TJ?

Have you grounded the hood? What kind of antenna/mount are you using? Are you running both + and - directly from the radio to the battery? Do you have a direct ground from the radio to the Jeep chassis? Is the feedline coax grounded directly to the Jeep at the antenna end? Do you know if the noise is from the ignition or the alternator?

Dick

Nick, where is your radio getting its power from? Does the noise go away when you disconnect the antenna? Have you replaced your spark plugs with non-resistor plugs?

Jerry N6TAY

Nick Hughes wrote:

Plus why the other guys said, try cleaning the battery terminals. If you're using the chassis for your DC ground, run another wire to your battery for it. Don't forget to fuse both sides.

Contact another ham on 2, 146.52 simplex will do, ask if he hears any noise, if he says yes, ( or better yet, alternator whine )....then it is time to clean the commutator rings....73`s Gene WB7NGI

The factory has a large braid from the hood to the frame.

NMO, on the rear of the Wrangler, above the tail light. 70cm/2m Larsen dual-band.

No, only hot lead from the batter to the rear of the Jeep. I believe it's 8 gauge wire. Negative lead goes directly to the chassis in the rear of the Jeep.

The radio's negative lead is grounded to the Jeep chassis, however not the radio 'chassis' itself. I can try doing this also.

Yes. The coax grounds to the NMO mount, which in turn grounds directly to the frame of the jeep (via screws).

Do you know how to distinguish?

Thanks for the help

I will try this.

Yes. They are Champion.

I may try moving an AM radio around the car. Hopefully, I can isolate it further.

Thanks

The negative lead needs to go directly to the battery, either at the battery terminal, or (as recommended by Chrysler) at the point where the negative battery cable attaches to ground.

You haven't said where the radio is mounted. It sounds like it might be installed in the rear with a remote head up front. In any event, the radio chassis ground needs to find the most direct route to the chassis. If you are using a remote head, you may need to use some ferrites on the lead between the head and the radio.

Ignition (spark plug noise) is a staccato, popping noise. Alternator noise is a high-pitched whine. Both change with engine rpm.

Dick

Put those resistor plugs back in. There is a good reason for the factory to use them in the first place.

Dick

If you know for a fact that the Champion plugs you installed are non-resistor (no "R" in the part number), then that is probably responsible for all or at least much/most of the noise your radio is picking up. Both the ignition and spark plugs must be resistor types or ignition noise will be horrible. The factory always installs resistor type ignition wiring and resistor type plugs for that reason.

Nick Hughes wrote:

I can't even imagine what you went through to isolate that down to the exhaust system Will. I'm impressed, I don't think I would have stayed with that troubleshooting procedure long enough to get to the exhaust system. I'm impressed!

Jerry

Will H> Weren't we just disucssing this part of the spark topic? Hardest

See

Not exactly the same problem, or discussion, but can you guys comment on the installation of a ground loop isolator to reduce noise in car radio?

Does it go in the b+ line ?? At the radio, or at the battery ??

Thanks !!

--James--