Topic: 102" whip high SWR

[Mega Baby Huey]

so i recently got a free Uniden Bearcat 880 that was in the back of a 4runner i just bought, and i decided that i'm going to set up my radio right this time... I already had my 102" whip mounted on a ball mount to my rear drivers side fender, so i was good to go in the antenna department... but after i installed the radio i have a 2.0 SWR reading on channel 1, and about 3.0 on channel 40. I made sure to ground it out really well, and the only better place would be to run the ground line all the way down to the frame... I've read somethings on the interwebs about needing a spring to really have a true quarter wave antenna, and i was wondering if that might be why... i was just curious if anyone here has played around with it, or knows more about it...

Pics of my current mounting location:

[88_Pathy]

I ran 8g wire down to the frame and it helped....

[86bobbedtoy]

mine is on my rear steel bumper,
I was always loosing ground.
just a wire from the base of the antenna to a clean spot on frame made a world of difference.
the wire is only 12 ga, I tryed heaver but same signal, so I went with what looked best,
I get great reception, all around my town, I do have some electrical help.

[locked 4x4]

Some of the other things that affect swr is the length of the coax going from the radio to the antenna.  Also grounding not just the antenna but the radio.  I always took my radios apart and turned them up so grounding became much more important.  I grounded the housing of the radio to the frame of the truck.  If swr is still high after that try tuning the antenna.  Cut small amounts off the top of the antenna and re-check swr.  I took almost and inch off mine back in the day to get it tuned in right.  Hope this helps
 

[Mega Baby Huey [OP]]

Wow! that was a bigger response than i was expecting! 

I'm going to try all of these things when i get home today and let you know what was wrong with my antenna! I'll do them one at a time so i know what really made the difference. There is so much written online about cb radio antenna's, and it's hard to know what's hearsay and what's fact...

I'm going down to Moab this weekend though, and i want my cb working right!

[Zs Confederate Toy]

I run the same antenna with a spring but I have never measured the SWR. It seems to do pretty good out on the trail.

[Mega Baby Huey [OP]]

I run the same antenna with a spring but I have never measured the SWR. It seems to do pretty good out on the trail.

That's how i was in my high school days... i only needed 20 feet to talk to my buddies, so i didn't worry about it. I'm pretty sure i screwed up that cb radio because of it though, because it got a LOT worse over the years! Now i'm going to make sure that i do it right!

[Mega Baby Huey [OP]]

well i got home and rechecked it today and the SWR reading is off the charts... I went to radioshack and took a picture of the coaxial cable they sold me and i think it might be the problem... here's the pics of it:



It says "indoor use" on it... i don't think it has the proper shielding on it for mobile application. i need to do more research but i think that's my problem...

[locked 4x4]

yea and its 50 ft.  Way to long.  Im not positive but i feel like it was suppose to be around 12 ft.  Also that looks like a poor quality cable

[Cheesemaker]

There are so many myths on this subject, that I've never seen anything that is set in stone from site to site, or book to book. 

The cable you got will work.  You want the 50 Ohm for a single antenna setup.  Less resistance.  All others are a higher resistance, so you will loose signal.  (Unless you run dual antenna's, you want the 75 Ohm wire.)  Just cut off what you don't need.  Preferably around the 18' length.  And just put on the needed wiring attachments.  Just do like the others said.  Make sure everything is grounded out good.  Even if you have to run the grounds all the way to the battery.  And I'd get the spring too.  You want the antenna around 108".    You are always gonna find a antenna in increments of 3'.  If they are like the firesticks, there is roughly 108" of copper wire spiral wound around a fiberglass core.  And those adjust by either screwing in the tip, or sliding a sleeve up or down the body of the antenna.

And just remember that your basic over the counter CB radio is only putting out 4 watts.  They are not a powerhouse like a Galaxy, Connex, the old Presidents, or General Lee's.  Where you can order them pumped up.  Or using an amp to boost signal.  4 watts isn't gonna be real picky, like a 10 watt tweaked unit that is heating up the coax, and antenna every time you mic up. 

You've done alot of reading online, just weed through all the info, and find the most common of information that is repeated.  I've never really had any issue with mine.  I've never used a SWR on any of mine, but I should one day. 

[Mega Baby Huey [OP]]

Ok... well i finally found out what the problem was and i'm ashamed at the stupidity of it, but i'll post it up anyways in case it might help someone in the future...

I tried everyone's suggestion... I grounded the antenna and the radio directly into the frame, bought and installed a spring, shortened the coaxial cable to almost exactly 18', and replaced the whole cable with better shielded cable i picked up at a truck stop... nothing worked. It all made it better, but i was still getting 8.5's an 10.5's on the swr test... I knew antenna trimming wouldn't fix a problem that big, so i knew it had to be something besides tuning! i checked the continuity between my antenna cable and the battery with a volt meter and i was at dang near perfect ground... but while i was testing this i accidentally touched the volt meter probes to the outer part of the male end (the ground) and the inner part (the power to the antenna) and it registered continuity... not good! I checked at the base of the antenna and again, i found that there was a connection where there shouldn't be... Upon further investigation i found it was due to faulty installation of the ball mount.

When i attached the ball mount to my fender a while back i neglected to read the directions where it said the middle hole should be an inch in diameter and not simply the width of the male connecter coming through the fender... this meant that my power was grounding out directly into the fender, and bypassing my antenna all together.
 

I drilled out the hole bigger so that the positive post would no longer touch the fender, slapped it back together, and WHAMOO... i had flat 1's across the board... and i immediately began to hear truckers from the interstate a couple miles away! It works great now and i have better reception than i've ever had before!

Thanks guys for all the responses and ideas!   

Here's pics of the install:

[Cheesemaker]

I love the second gen dash!!    Best place for the CB, right under the radio.

[Zs Confederate Toy]

Lookin pretty damn good. Like a airplane cockpit haha

[fordh8r]

Ok... well i finally found out what the problem was and i'm ashamed at the stupidity of it, but i'll post it up anyways in case it might help someone in the future...

I tried everyone's suggestion... I grounded the antenna and the radio directly into the frame, bought and installed a spring, shortened the coaxial cable to almost exactly 18', and replaced the whole cable with better shielded cable i picked up at a truck stop... nothing worked. It all made it better, but i was still getting 8.5's an 10.5's on the swr test... I knew antenna trimming wouldn't fix a problem that big, so i knew it had to be something besides tuning! i checked the continuity between my antenna cable and the battery with a volt meter and i was at dang near perfect ground... but while i was testing this i accidentally touched the volt meter probes to the outer part of the male end (the ground) and the inner part (the power to the antenna) and it registered continuity... not good! I checked at the base of the antenna and again, i found that there was a connection where there shouldn't be... Upon further investigation i found it was due to faulty installation of the ball mount.

When i attached the ball mount to my fender a while back i neglected to read the directions where it said the middle hole should be an inch in diameter and not simply the width of the male connecter coming through the fender... this meant that my power was grounding out directly into the fender, and bypassing my antenna all together.
 

I drilled out the hole bigger so that the positive post would no longer touch the fender, slapped it back together, and WHAMOO... i had flat 1's across the board... and i immediately began to hear truckers from the interstate a couple miles away! It works great now and i have better reception than i've ever had before!

Thanks guys for all the responses and ideas!   

Here's pics of the install:

Funny you mention that...when I first read your post, that was the first thing that came to mind. But I thought, "nah, he musta already made sure of that...".      Now I wish I had said something. well, glad to hear you got it figured out.

[Mega Baby Huey [OP]]

Lookin pretty damn good. Like a airplane cockpit haha

I got the inclinometer and everything! Whenever someone asks about my "airplane gauges" i always tell them it's for when we hit a jump so i can fly us in!

[Mega Baby Huey [OP]]

well, here's some pics from Moab anyways... i still love that 102" antenna... i just have to warn people to look out for it!