I hooked up my Radioshack SWR meter to try and tune my antenna. First I calibrated it then when I test it by pushing the talk button it pegs the needle way past the the 3 mark. I tried tuning the antenna, but it never changes.
I have the Firestik II on the tailgate of my trooper.
Thanks for any help.

Check the wiring connections on the antenna. If you have the antenna on the rear door it may not be getting a very good ground too. The body of the truck acts as the ground plane for the antenna so you need a solid connection to the main part of the truck. You could try running a wire between the door and the rest of the body and see if that changes it. There should be something you can hook to on both sides to test, and if it helps you could hide a short wire right by the hinges.

Pre made cable or a termination of cable to a connector?

If the termination was made by you, then ensure the shield is NOT touching the dielectric. Also ensure that there is no foil insulation on the dielectric. And the center conductor is not touching the outer jacket.

Otherwise, if the screw on the antenna is not making a change the ground is suspect. The mounting screws could be touching the conductor of the antenna screw to the bracket attached to the vehicle. Make sure the nylon washer is seated properly within the hole of the bracket, and isolated within to top, bottom, and side.

Huh? The shield touches the dielectric the full length of the cable, don't it ?

Did you mean:

make sure the shield is NOT touching the CENTER CONDUCTOR ?

I think yes, and of course that's true...

Is there a sensitivity setting on that SWR meter ? or is it one of them "preset" ones ? Does that one have a Forward and Reverse switch on it ? I think it does, cuz when you say "calibrate it", you mean set to forward, key mic, set sensitivity to set meter at full scale, unkey, switch to reverse, and key up ? Is that when it pegs full scale ?

You can do a rough test on MOST swr bridges by switching the IN and OUT on the coax cable and comparing the readings to what you get in the "proper" direction. If they are very different (but opposite, F becomes R) then beware of a funky swr bridge.

I said MOST... there are some that may not work properly in reverse, and I don't know a thing about the RS ones... may all be BS on my part... <img src="/forums/images/graemlins/smile.gif" alt="" />

<img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/patriot.gif" alt="" />

I checked all cables an connections and they are good. I tried the ground wire and a long jumper wire straight to Batt. Neg and there was no change.

What nylon washer are you talking about? Is there supposed to be one between something?

Yes, I was correct in my statement. Certain types of RG58 (50 Ohm) cable has a foil shield on the dielectric with the stranded shield outside of that within the PVC jacket.

There ARE occasions that when stripping/folding back the stranded shielding a stray strand or so does not cooperate and shorts out on the center conductor and/or the foil covering the dielectric if in fact this cable contains that foil. There are LOTS of ways this condition exists and a slight shorting of a few strands of shield can throw off the SWR.

Hope that makes sense... hard to explain on a forum, but I could go into further detail if needed.

With your antenna mount, it has multiple pieces, from top to bottom:
antenna
antenna coupler (where the antenna screws onto)
Nylon spacer (this prevents the center conductor of the coupler to short onto the bracket/body/mount)
bracket or body/mount etc.
star washer
nut
the bottom has the BNC threads that the cable connector attaches.

The coupler must NOT touch the body and short to ground or it will cause faulty SWR readings.

Thanks, I think the nylon washer is the culprit. I remember it came with my mount but I didn't use it(I'm a noob) <img src="/forums/images/graemlins/rolleyes.gif" alt="" />. I'll prob. just buy a different mount because I looked all over for that darn washer and it is nowhere to be found.
Thank you guys for the help; I'll let you know if this solves it.

Wes, I'd take a quick jaunt down to the hardware store before buying a whole new mount. They should have assorted sizes of non-conductive washers.

Good point, I'll just pick up some plastic washer or something. Kinda in a rush; trying to get everything ready for rockport.