What does it mean... (SWR issues content)

The PL-259 contacts the underside of the mount. I was under the impression that the PL-259 should contact, while the stud should NOT contact. Am I correct here?

Additionally, I tested for continuity across the door hinges and they provide a perfectly good ground for the door, so no additional grounding should be required.

I see. I didn't notice any distinct issues with my old setup. I only changed it because it was haphazard and haphazardly installed. Base-loaded steel whip antenna with an old corroded aluminum mount, fed by 9 feet of coax that wasn't very well routed. I was told that too short of a coax can affect performance and SWR.

 

Well I don't get this at all.

Disconnecting the ground strap entirely results in the SWR dropping to 3-3.5.

Is it possible that the wrong kind of coax could cause this? I'm using Mini-8. Coax says "Mini 8/U Type #3050 RoHS" on the side of it. It's American made, not Chinese. I'm starting to wonder if I should just use RG-58 instead.

 

So.

I'm standing in the Pilot in Clear Lake, IA. I notice that Truck Spec Terminator II "poor man's big coily antenna" is $20 off. I said, what the hell, and bought it.

Tossed it on. SWR on channel 20...wait for it...1.4. After a bit of tuning, I've got it down to 1.2. We'll see if it holds. Everything's wet right now, with my luck, that'll make a difference somehow.

 

And what do you know? All is dry, SWR is back at 6+. What the #### gives!?

 

I didn't think grounding issues could cause a 5+ increase in SWR, but I'm down to try almost anything at this point. Thinking of running a nice long line from the mount down to the battery box. Should be a good ground, seeing how that's bolted to the frame right next to where the batteries ground to the frame. And it's quick 'n easy to undo...

 

So, I got a flatbraid and ran it from the mount to one of the torx bolts behind the sun visor, per the advice of WalcottCB. SWR went from 6+ to 2.5-3. Then I tested a new coax, just ran it through the window and let it lay out in the cab. 18ft Mini-8 from WalcottCB. SWR was 1.2-1.3 again.

Then I routed it into the cab and up to the radio, and it jumped up to 2.5-3. Once again, the excess coax is NOT coiled. I just let it loose up behind the radio.

Anyone have a brick wall I can smash my head on a few times?

 

Would grounding the radio itself make any significant difference?