swr problem with new truck, radio, and antenna

If you've got an ohmmeter, it's worth testing your coax for shorts & opens. Just because a shop made it doesn't guarantee it's right; they might not have checked.
Make sure you've got continuity between the center pins on the coax (unplug it from the radio and antenna, of course). Next make sure there's continuity between the outer shell on one end and the outer shell on the other end. And make sure there's *no* continuity between the center pin and the outer shell.

Aside from that, if you had a serious fault you probably wouldn't have been able to talk with a station that's 3 miles away.

It's possible that you've got a bad external meter, as you've suggested. Something you can try is to set the calibration level on the external per usual. Then, without touching the FWD/REV switch or the calibration pot, just reverse the connections to the meter and see what the SWR reads. If it's different from what you got by flicking the switch from FWD to REV in the usual fashion, then the pot or switch are faulty, or maybe there's just extra RF spraying into the meter box, or something similar.


BTW, that's also a good trick for folks using inexpensive meters to check VHF systems.

Also, is that cab fiberglass? If not, and if the mirror bracket already shows zero ohms from the bracket to the door and/or main body, then there's probably no reason to bother with the ground leads, as the bracket is already grounded.

And, since it happened with someone else -- are you doing your tests with the truck doors closed, and away from a building or other big truck? Any large object in the near-field of the antenna can affect its performance, but it should still read more-or-less the same on both meters, if they're not defective.

Hope that helps,
-- Handlebar --

 

I'd scuff up that black paint some where the mount goes but as I've recently found out it's certainly possible to have a bad external meter. I adjusted with the built in one til I got a new external meter and all was good. The antenna warning light never came on when I adjusted with the built in and after getting a good external and comparing it wasn't that far off.

 

you likely used shielded/coated wire correct(just like your red/black 12ga power wire)
That acts like another antenna which is causeing reflect. Loose it ASAP.
The meter on the radio only zero's the radio,it is not a true calibration feature.

That coating on the mirror hanger is powder coating and needs removed completly in order to catch a viable ground at the mount.

I use 5/16 X 3/4"self tapping screws and a good drill motor to make ground
on those style hangers.One screw thru the mount and into the hanger
works real good.