Many years ago when I was more into radio(just now got back into after a few years) a tech explained it to me as "a ground is a ground is a ground", and I took it that he knew what he was talking about, and made sense to me at the time. Fortunately I have nog into many discussions about this, and assumed he knew what he was talking about but you know what that means. I always double ground where I can anyway, and add extras if feel needed.
Hope I did not offend anyone here, and will take it as a lesson learned even though I have been in, and out of radio since CB was first started back in 1960.
Larry

 

Again, no offence taken Larry. I got my HAM license back in 96' and was into CB a bit before then. I sure as hell don't claim to know very much, but I do know a little about radio. Most HAM radio ops I know put my radio savvy to shame...!!!.....lol

 

You know, I think that same guy was assigned in the Autopilot shop at Udorn RTAFB, Thailand. I never met him, but I did come across his work. You see, we had this EC-130E on which the Automatic Direction Finder (ADF) did not work. It would sometimes find the correct bearing for the target, and sometimes not. Well, since this was used to help triangulate for downed pilots during the Vietnam War, it was rather important that we get it fixed. It took us nearly three months to figure out what was wrong.

It seems that there was this autopilot TCTO (modification) that had been installed. And the tech on this particular aircraft needed to run a wire several feet to a grounding lug under the flight deck. Well, this enterprising tech, "knowing" that "a ground is a ground is a ground", saw this shielded cable that ran within inches of his modification install. So, he scraped off a small sliver of the plastic insulation around the cable, then soldered his ground wire to the shield of that cable. This was before Time Domain Reflectometers (or at least before us USAF avionics techs had them), so it wasn't until we were doing a visual inspection of the entire coax run for our ADF antenna during extended downtime for periodic aircraft maintenance that we discovered his misdeed.

 

I would say that is an understatement....... Looking for some poor guy in a hurry isn't a good time to FIND OUT that a ground ISN'T a ground ISN'T a ground.......lol....

 

Sorry for the simi duplicate posts. Yes it was a bad ground.

My SWR is good now
I couldn't get a good ground just using the Ultramount bolted to the body no matter how much paint I scraped off. I went and got a 10 guage wire and a couple of crimp on connectors and ran it from the antenna mount and drilled a hole in the frame. That gave me better readings:

CH1=1.8
CH19=2.5
CH40= just in the red at 3.2

I still couldn't get the higher channels out of the red. So... I swaped out my 3' Firestik for a 4' one and after adjusting a bit I got these readings:

CH1=1.5
CH19=1.8
Ch40=2.0

Much better. Thanks everyone for all the replies.