I just installed my CB (Cobra 19DX) a few months ago (see thread: https://www.ranger-forums.com/forum2...ad.php?t=53566)

Since that time, I've been through a couple of antennas, as the parking garage at work as been a little rough, lol. I just got a Wilson 4ft. whip antenna - which seems to be perfect for the garage. Unfortunately, my SWR is still really high (above 3 all around at its best). I've had a few problems with this in the past where I would just start fiddling with it and moving it around and it would, all of a sudden, start working again.

I've checked the cable by trying a new RG-58 cable. I've also replaced that little piece that goes between the cable and antenna (it was pretty beat up from me trying to make it better). I am using an Alon bracket on the left side of the truck. I ran the cable in through the tail light (it's notched) and underneath the truck. Again it has worked in the past.

Now for the great part. I took the antenna off of the truck and just had it plugged in through my SWR meter, with me holding the antenna in my hand. If I held the antenna itself, the SWR was still really, really high. However, if I held it on the bottom of the antenna where my hand and fingers were wrapped around the base across the top of the cable to the bottom-most part of the antenna, the SWR dropped to 1.5! If I started to squeeze the antenna, the SWR would go back up - I had to hold in it the right spot and hold it loose. I can pretty much reproduce this at any point. So, with that, I'm totally lost. I just wanted to see if you guys had any ideas.

Sorry for the long post, but I'll take any suggestions at this point, lol. Outdoorsman and I are planning a small trip on Friday, so i want to have this working by then. I'll probably take it down to Apollo Communications (here in town) to have them look at it if I can't figure anything out by Monday.

 

Sopunds like you need to tune the antenna. Hook the SWR meter between where the feed line connects to the antenna bracket, and tune the antenna per the manufactures instructions, that should fix your problems.

 

Given I have only the slightest idea as to what I'm doing - this would be different from tuning it at the radio (feed line from the antenna through the SWR meter and into the back of the radio)? There were some instructions on the back of the package - so I'll check all that again tomorrow.

 

Yep, with that way, your tuning the coax too, so when the coax moves, your SWR gets squirely on you. Tuning the antenna with the SWR meter connected right to it, removes that from the process.

 

An SWR meter doesn't tune anything. It is meter and only tells you what is happening. You can not tune anything by turning the **** on the meter.

Are you properly calibrating the meter?

 

yes, that was my first thought, lol... It's a pretty simple meter, flip the switch - calibrate the meter by adjusting the gain until the needle is right at the edge of the red line (to the right-most part of the meter). Then you flip the switch back and do it again to get an SWR reading. In some cases, though, the reading would be really high - near 5! That's why I thought it was the cable - I had hauled a bunch of bricks for my brother and my truck was really riding low - so I though I might have smashed the cable. I get the same response with a new cable, however.

 

Anything on this page should help you too: http://www.wilsonantenna.com/tsswrg.htm

 

Then there is probably a ground fault somewhere. Usually it is at the antenna mount. The center conductor is probably making contact with the shield or other ground.

 

Ground fault did cross my mind. I run into the problem with sound systems where a problem with the grounds changes the impedance and causes buzz.....I just didn't know where to look. It's a new cable, so I wouldn't think I would continue to have that problem.

I'll read through the Wilson site to see if I can grab any more ideas

 

buy my wilson 5000 :)

make sure your radio is tuned and peaked before u go and mess around with the antenna

 

I had an issue with my 5ft wilson whip that was somewhat like this. If i took the ground lead (which is not actually a ground, it has to do with the impedence mathing) and connected it to the outside edge of the base of the antenna i would pic up much more. I dont know why this is, but maybe it could help.

 

Well, it has worked fine in the past, but I really trust the guy over at Apollo. I've heard great things about that shop, so I'll go over and talk to him to see what he thinks. He'll also be able to tune and peak the radio as well---This might get a little expensive, lol.

 

Ya thats your best bet. I had my radio peaked and tuned, it cost me $35, i only paid $15 for the actual radio. Its become a fun and expensive hobby.

 

....which is no different than the others

 

lol yeah all hobbies get expensive

 

Went down to the guys at Apollo. They had me a try a few things unsuccessfully before hooking up some way cool meters. There was definitely a ground loop - or a short in the coax as we expected. The Alon bracket is the source of the trouble, combined with the coupling (piece between antenna and Coax). The hole is smaller than 1/2 inch- so the center conductor was shorting to the ground...FireRanger hit it on the nail! In order for the little insulator to keep it from hitting the inside of the bracket, I need to drill that hole out a little more (that'll be fun!). That also explains some of the other odd issues I've had before. I'll try and get that drilled out in the next couple of days and see if that solves our problem. haha, you should have seen the guy's face when he read the SWR, lol!

 

scrape some paint off the mount. make sure you get a good ground.

If you still have trouble PM me i will be glad to help.

The best antenna is the 102" whip with a 6" extension

Flat 1.1 all 40 channels

also make sure you use 18' of coax

 

well, the first problem to cover is the coax lead shorting with the ground. Once i fix that, we should be good to go. I do have to be careful with the size of antenna that i use, since I park in a relatively small garage at work. My main goal at this point is to get it working decently well for our trip on Friday. After that, I can work on improving it more. If I run into any problems, I'll take you up on that help! Radios aren't entirely my cup of tea.

 

the nice thing about the 102 whip is the fold over nice

 

well, I drilled it out yesterday - and that fixed the problem. I'm not sure why I've been the only person to have any problems like this.

The coupling I was using to go from the coax to the antenna is 1/2 inch. The hole in the bracket was less than half an inch. The center lead, through the bolt, was making contact with the mount - grounding out the cable. It was worked before because I was able to get it on there just right, and tight enough, so that the shorting didn't occur. When I drill out this hole, the lip of the white plastic piece fit right through the hole. This allowed the bolt to go through the middle, and the bottom part of the coupling to be held just below the bracket - without touching. The antenna then sat on top of the plastic piece. I'll take a picture and post it back up.

my SWR is near normal range now. It's still up a little across all channels and not tuned well at all. I'll take a better look at it this morning to see if I can get it to work better.

 

ok :) I said that totally wrong in my last post


The problem I continue to have is that the SWR is lower on channel 1 than on 40. Yes, I know this means it is electrically long -- I pulled out the tip and it does the same thing still. It isn't going to totally harm the use of the radio on the trail, it just isn't best. That plastic piece goes under the bracket. I did try it both ways - and this worked best (although both work...the tailgate has an effect on the radio if it's on the top. Tailgate down = higher SWR...chew on that).

Pics:

The plastic piece (notice that little lip I was talking about:



Cable to coupling, to plastic, to bracket:







It's working great now -- it just happens to work much better on the lower half of the band.

also...I know the hole isn't perfectly round. I don't want to talk about it.

 

You have that plastic insulator on the wrong side. The piece where the cable connects should be flush against the bracket and the insulator should be keeping the threaded part of the antenna from the touching the bracket. You are going to fry the finals on your radio if you keep using it like that.

 

thats the problem your shorting the radio out. bushing on top, the bottom should short to the ground. the center should never. If your Swr continues to be bad then you have an improper piece of coax. on a firestik it should be 18ft with rg58 if you use RG8x mini it should be 14.25ft

Put the bottom stud so it is centerd of the mount put the washer with the lip down, so it keeps it all centered as best as possible. Then tighten it all down, Install the whip and tune from there.

 

The coax length is pretty much irrelevant. That is mostly a myth.

 

I wish i could agree, but I can not, ON HF it does matter I can take my tuned 1.1 102 whip put on 18ft of rg8x and get 2.0
run 14.25 get a 1.1

Its a debate that be argued till the end of time but on hf it does matter.

You will improperly tune your system.

I have read many arguments and write ups even arrl talks about coax lengths,