did I fry my cobra 75

[WYRD]

the last trip out Chris mentioned that I havent been running a good ground plane. I have my antenna mounted to my plastic license plate frame. The cb works ok in close range, so I never thought twice about it. Today I went out and noticed I dont get any squelch static at all. So I installed a seperate #6 ground wire from the antenna to the tub and still no static. I dont know what the swr is, I know when I hooked it up it was high like 3+. The radio still works close range but I am still concerened about not having any static..

what do you think

[Roger]

The antenna is still grounded through the coax so you probably didn't fry it, but keep your fingers crossed.

I would move it from the plastic lic plate frame. There are other ways to mount it. You can purcase a bracket that attaches behind a rear tail light or just get an "L" bracket and bolt it right to your tub.

Sometimes the asmopheric conditions are right and there won't be static. Also, your radio might have a built in circuit to eliminate static - I think.

I see you live in the high desert and if you are anywhere near the truck stop at US 395 & I-1, take it to the CB shop there and have them check it out.

[Dave_W6DPS]

the last trip out Chris mentioned that I havent been running a good ground plane. I have my antenna mounted to my plastic license plate frame. The cb works ok in close range, so I never thought twice about it. Today I went out and noticed I dont get any squelch static at all. So I installed a seperate #6 ground wire from the antenna to the tub and still no static. I dont know what the swr is, I know when I hooked it up it was high like 3+. The radio still works close range but I am still concerened about not having any static..

what do you think

It is probably not the radio--Cobras usually have some protection designed in that keep them from frying like the older models did.

As for the antenna mount, the license plate frame could be the worst choice on Rubicons, other than maybe the rear bumper.

You should see a substantial inprovement in performance if you can get the antenna above or away from any roll cage or body metal.

Unfortunately for CB you are limited to mobile antennas that start out weak and are easy to make worse. This is just the nature of the eleven meter wavelength. The same thing is what causes hams who run mobile HF to have those big, ugly, weird looking antennas (that also don't work nearly as well as a simple dipole in a tree).

Any metal on your vehicle that is parallel to the antenna will cause problems. The closer they are together, the worse it will be. Mounting below the level of the roll cage causes the signal to couple into the cage, rather than radiating.

This is also why your received signals are so week. The antenna works about as well either receiving or transmitting.

SWR is only one thing to consider--and not the best indicator of overall performance, but an SWR over 3 to 1 indicates bad things. You may or may not damage the radio, but it just can't perform well.

I'd look into other mounting options for the antenna.

Dave_W6DPS

[chris142]

A Jeep is probly the worst vehicle to mount a CB antenna on. A van with a nice flat top would be a great choice.

But like I said your antenna needs to be mounted to metal. It uses the vehicle as a ground plane and the shape of the ground plane as well as the mounting point effect the RF output.

Enough of that stuff. Get it mounted to metal then go see the guy in the van at the Pilot truckstop.

Once mounted to metal with a decient SWR it will work fine for your use.

BTW today I was at the Gold Peak mine off of Camp rock rd and was talking to a guy in Wrightewood!

[Russ Chung]

the last trip out Chris mentioned that I havent been running a good ground plane. I have my antenna mounted to my plastic license plate frame. The cb works ok in close range, so I never thought twice about it. Today I went out and noticed I dont get any squelch static at all. So I installed a seperate #6 ground wire from the antenna to the tub and still no static. I dont know what the swr is, I know when I hooked it up it was high like 3+. The radio still works close range but I am still concerened about not having any static..

what do you think

I hope that you attached the ground wire to the antenna MOUNT not to the antenna itself. The outer jacket of the coaxial cable connects to the mount and the mount should connect to ground. The center conductor of the coaxial cable goes through the middle of the mount, through the plastic washer, and connects to the antenna. The plastic washer insulates the antenna from the mount and from ground. The antenna should NOT be grounded.

If you have an ohmmeter, you can test the mount and the cable.
1. With the coax cable connected to the mount, check for continuity between the coax cable connecting ring and ground, and
2. There should not be continuity between the antenna and ground.
3. Disconnect the coax from the radio and from the mount to check for an internal break or short in the cable: a) Attach the ohmmeter to the center conductor at each end of the cable to check for continuity. There should be continuity; if not, you have a break in the cable. b) Attach one probe of the ohmmeter to the center conductor of the coax and the other probe to the outer connector of the coax. There should not be continuity. If there is continuity, you have a short in the cable.

[WYRD]

Thanks guys I will mess with it this weekend and post the results

[Nipple Twister]

Hmmm....

....and you thought you could stump these boys.....hA, never.
All kidding aside good luck with getting it working and not hurting your radio $$$$$$$$. I think they pretty much nailed it as far as how to go about getting it catching as well as pitching.......
Have you thought much about HAM???//

[WYRD]

....and you thought you could stump these boys.....hA, never.
All kidding aside good luck with getting it working and not hurting your radio $$$$$$$$. I think they pretty much nailed it as far as how to go about getting it catching as well as pitching.......
Have you thought much about HAM???//

yeah I would like to get a ham license eventually, but for now the wife and I dont get out on the trails as much as we (I) want to. Not to mention lots of other "mods" on the li$t before spending money on the Ham radio. J.E.E.P.