CB SWR level is extremely high

[SSTJ]

Well, I took a good look at how my grounding strap had been placed between the coax connector and the underside of the mount. At the time, I had thought "Hey, I'll just stick this strap right where everyone tries to ensure a good connection between the bottom half of the connector and the lower side of the mount." But it turns out that the ring-terminal on my strap was also contacting the inner, threaded portion of the connector, which passes through the hole of the mount, and which is insulated from the outer part of the connector (that outer part being what's supposed to contact the underside of the mount). Pic below to explain better.

So yes, I think I was inadvertently grounding the antenna itself. I moved the grounding strap over to one of the other holes on the mount, and ensured a good metal-to-metal connection. Will test in an open area later today.

 

[SSTJ]

Well, many thanks to @gaabbee for helping me sort this out. Once I removed the mis-placed grounding strap, I was able to tune the antenna. Pic of re-positioned strap below.

Still, after some careful tuning, I'm unable to get things below 2.3 or 2.4. Was it because I was only 50 feet from some traffic? Could my tub not be well-grounded to my frame? Dunno.

Something else that threw me off was how my SWR meter would occasionally jump in the middle of a reading. While holding down the PTT button, it once or twice dropped by a full 1.0 or so, stayed there for a second or two, then returned. Nearby traffic? Cheap SWR meter?

Anyway, thanks again. I can live with 2.4, but I'm going to keep thinking about this, because it's a bit disappointing.

 

[gaabbee]

Well, many thanks to @gaabbee for helping me sort this out. Once I removed the mis-placed grounding strap, I was able to tune the antenna. Pic of re-positioned strap below.

Still, after some careful tuning, I'm unable to get things below 2.3 or 2.4. Was it because I was only 50 feet from some traffic? Could my tub not be well-grounded to my frame? Dunno.

Something else that threw me off was how my SWR meter would occasionally jump in the middle of a reading. While holding down the PTT button, it once or twice dropped by a full 1.0 or so, stayed there for a second or two, then returned. Nearby traffic? Cheap SWR meter?

Anyway, thanks again. I can live with 2.4, but I'm going to keep thinking about this, because it's a bit disappointing.

View attachment 242046

When I tune I usually just do it on channel 20 and where ever I can get the lowest number is what I stick at. Lazy I know but once you get into the sweet spot height wise you are just making small adjustments. Your shorter 2’ antenna is probably what’s holding you back a little but you should be happy with what you got for now.

 

[Jerry Bransford]

Ok, apologies for hijacking this thread, but my problem is the subject of this thread, so here goes:

I have a Uniden 520XL that is wired directly to the battery. From the CB, I have this coax (18') going to a firestik connector on a red hound mount, on which I've put a 2' firestik antenna. Some pics are below, and showing that I've scraped away the powder coating from where the coax meets the mount. That's also where I've attached the grounding strap. I ran the strap to underneath the soft top clip on the back of the tub, and I scraped the paint away under there too. Stuck a washer under the black clip and tightened down with a bolt and nut to ensure a snug fit against the metal.

I have the same Astatic SWR meter that Chris linked earlier in this thread, and I'm getting SWR levels over 3. This is after playing around with antenna lengths, testing in an open area (large empty parking lot), etc.

Some pics are below. Any ideas? Many thanks.

View attachment 241702View attachment 241703View attachment 241704View attachment 241705

I'm highly suspicious the braided wire's ring connector you're using to ground the antenna mount just below it is also shorting the center stud that passes through it dead to ground. The center stud passing through your ring connector is signal going to the antenna. The ring connector is ground.

Edit: Whoops, call me a day late and a dollar short. I was directed to your post via another thread and just saw it.

 

[SSTJ]

I'm highly suspicious the braided wire's ring connector you're using to ground the antenna mount just below it is also shorting the center stud that passes through it dead to ground. The center stud passing through your ring connector is signal going to the antenna. The ring connector is ground.

Edit: Whoops, call me a day late and a dollar short. I was directed to your post via another thread and just saw it.

Thanks Jerry,

Yes, I did eventually figure that out, but it took me a while!

I’m still surprised that I can’t get it below 2.4, which is why I was wondering if perhaps my tub weren’t grounded well to the chassis. I don’t know how to test for that, so I’ll just keep tinkering.