Wilson 5000 Trucker/29GTL SWR Issue

[WyattEarp]

Hey,

I have a Cobra 29GTL mounted in my pick up with a Wilson 5000 Trucker on a steel bar with a modified mirror mount that has a fold-over mount as well. Here is a picture of the mount.

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My SWR's all around are 2.5-3+. I have tried raising/lowering the whip, taking off the fold-over mount, tried a ground wire attached to the antenna mount to the truck chassis, different coax. Nothing is working. My main coax is 18ft and the other coax is 12ft. Neither worked. I did notice that when I touched my face to the D104 mobile mic, the SWR's did go down. Not much, mainly like 2.3 or 2.4. What could be causing this SWR issue?

['Doc]

The first thing that comes to mind is that 'fold-over' thingy has made the antenna longer by the length of that 'fold-over' thingy. Try removing the 'fold-over' and see what happens.
- 'Doc

[Hazelnut 7201]

That looks like the Wilson HD stud mount that you are using. I never had any luck using those.
They short out somewhere and caused high SWR for me. I would try a different stud mount.

[231]

First thing that comes to my mind is also likely the stud assembly. Just because you hooked up a ground wire the mount doesn't mean it has sufficient RF grounding. The fact you saw your standing wave change by touching the mic sort of indicates to me an RF grounding issue. If it were me I also would dump the fold over until you get things working properly. I'd also run a lug connector and a #12 wire (or bigger) from the bottom of the stud (where it makes contact to the mount) and run that to a chassis or good body ground ("Shiney metal point, not just a an old bolt connection)...and NOT from just the mount or shield of the corroded PL-259 connection.

Also, I could be wrong, but that PL-259 doesn't look like it's in all that good of shape to me. Are you trying to use all old stuff? Take an ohm meter to antenna shaft and stinger and make sure you have continuity. The Wilson 5k has been known to have the coil break loose too. That is where I would start anyway.

Good luck.

[Texas Mobil 219]

If it were me. I would change the mount and make a better ground wire to the frame. Ground the radio and amp together and then down to the frame also. The connector looks old. I would change it and shorten the coax so that there is just enough to get from point A to B.

Retune the antenna and should be good to go.

[WyattEarp]

Well, I checked the antenna for continuity and its good. I took the fold-over off, got a new 9' piece of coax with new connectors on it, got some 12g copper wire to ground the antenna mount and ground the radio to the truck chassis. I used 3 different stud mounts as well. SWR's still around 2.5-3+ all around. No change at all. I'm about to buy me another Predator 10K and be done with it. I had one years ago and I didn't have any problems with it at all.

[Texas Mobil 219]

You are using a external swr meter to check your reads right. I wouldn't trust the radio meter.

Anyway. Check to see if your insulator has any cracks in it. And that its on top of the mount. Not the bottom. Have you grounded the radio and amp (if you got one) to the frame.

One more thing. Get another antenna. Maybe a 102 or a 5'5'' francis, shoot even a k 40. Just something you can thro on to make sure that its not the antenna itself.

[WyattEarp]

Yes, I am using my PDC 600 meters to check. I've checked pretty much everything. I've used newer mounts and all.

Yes, I did ground the antenna mount and the radio to the truck chassis. I don't have an amp so...

I'll have to get some other antennas from my friend to try out since the Wilson is the only one I have atm.

[Texas Mobil 219]

Cool man. Let us know what happens with another antenna.

['Doc]

Just for grins, have your friend check what you're doing, or someone else. One'a them 'forest/trees' thingys. Something is being missed somewhere, maybe someone else will 'see' it. Aggravating as hell, ain't it?
- 'Doc

[Texas Mobil 219]

Just for grins, have your friend check what you're doing, or someone else. One'a them 'forest/trees' thingys. Something is being missed somewhere, maybe someone else will 'see' it. Aggravating as hell, ain't it?
- 'Doc

LOL, I can relate to that doc. One time my wife took my 108 so she could get into a parking garage. She put it back on except with the insulator on the bottom of the mount.