My current setup is a Cobra 75WSXT and the Cooltech antenna mount/firestick combo.
I'm running one of the fuse taps and plugged into the fuse for the switched dash power (I think it's the left power port?), and ran the ground directly to the negative battery terminal.
The coax was routed along the upper edge of the tub, down under th drivers door, behind the pedals, and behind the center of the dash to reach the base-unit behind the glove box.

No alternator noise at all, but I still have to check the tune with an SWR. If all seems ok, I'm gonna drill a small hole int he side of the fuse block for the wire, and caulk it real good so water/etc doesn't get in there.

 

Ok, thought I'd snap another pic - this one showing the Cobra 75 Connector Box install below the glove compartment. It was very easy and quick to mount, and although it may appear to be flimsy, the box feels rather solid in this configuration.

I have excellent continuity between the two small red squares, and also from the box to other body ground points. The red/black power and ground wires from the connector box run over to the passenger side firewall and through to the engine compartment.

Anyone see anything obviously wrong? How about pure conjecture? Should I buy a new JK, and start over?

 

Check to see if there's a difference when the A/C and/or fan is on. Your CB is mounted close to an electric motor, and there might be some interference.

The whine might also be coming from your alternator. You could borrow a second battery and power the CB directly from this independent battery. If the noise goes away, you know it's coming from your power - probably the alternator.

If it's coming from your power, add a filter as close as you can to your CB...



js.

 

I mounted mine in the same spot and my Cobra 75 is crystal clear (See my sig for write-up). The only difference in our installs is I used wire connectors at the end of the wires for the battery connection and I grounded to the body not the battery. There is an unused ground bolt just behind the battery tray that worked great.

 

I have the same CB, mounted in the same spot with + and - terminated at the battery with solderless connectors. If I pull my antenna off, no whine but with it mounted, the same problems you're having. I am definitely picking up my whine through the antenna, not through the wiring to the battery.

 

I'm now using "ring terminals" on the CB power and ground wires. I've also pulled ground off the battery, and am now connected to the dash/instrument panel frame via the black bolt just above the leftmost red square (see below pic).

When running around doing some chores this afternoon, I heard someone very clearly on Ch19. Asked for a radio check, and they came back with, "Loud and clear!" I thanked them, and continued on my way. Should have asked for a location, but I was so shocked about the radio clarity it didn't occur to me. Now if I can hook up with the one guy I know who has a solid CB setup, I can do a little more testing and maybe relegate this issue to the past.

 

Upon further reflection (and testing), I'm not absolutely positive my noise was a "whine" (although I know I've been doing a bit during this install). It was more like loud static, which sometimes correlated to engine ignition, high engine RPM, etc. (I could also add - applying the brake, or depressing the clutch, but I'm afraid someone will say I'm imagining things).

Still may have a problem, but I've sort of convinced myself (for my sanity's sake) that maybe everything is okay now. I'll post a follow-up when I've had a chance to test the unit further.

Thanks to all who have reponded thus far.

 

Make sure that everything is grounded. An improper ground will drive you crazy...

 

Sorry for dumb question below, but it just occurred to me that I might not know how to check for a good ground. I initially thought that it was as easy as checking for continuity such that:

Good continuity = Good ground
Bad or no continuity = Bad ground

I have a feeling that there's something more to it than that based on all the posts in various threads to check ground, and then double check ground, and then when you think all is well . . . triple check all grounds just for good measure.

Would someone please explain how to check for a good ground, and whether it can be done without turning on the CB radio. Or, is it more like "black magic" in that you check for good ground, not with a VOM, but through a continuous process of installing, uninstalling, and reinstalling all the components that comprise one's radio system?

Thanks for your explanations.

 

If you have a whine over the speakers the cause usually in audio setups is that the power and speaker wires are next to each other. Thats why good setups and car design have cables running on either side. One side for power and one side for audio.