Need help with Fiberglass Antenna Purchase.

[Dmax5er]

Hi all, I new here because i found myself stupid when it comes to all this cb stuff. I went to the flying J and bought a Cobra 19 a 4' fiberglass antenna with small spring base with the 90deg mirror bracket, performance on this setup is terrible, i can get out maybe 3 blocks,, I have a 93 jeep wrangler, I mounted the antenna to the spare tire bump stop on the right rear corner of the jeep, the antenna extends 6 inches above the top.... I just bought a SWR meter and haven't had a chance to use it yet but the antenna i bought, i was told is a piece of crap and to get a firestik 2. Radio is stock for now. Can i get some input from you experts on which antenna to buy next, I dont want to go too tall because of ripping the antenna off in the woods..
Thanks..

[Red Warrior]

For an antenna to be effective, at least 2/3 of the antenna must be above the body of the vehicle, otherwise the majority of your signal is being absorbed by the body. Reconsider your mount. Also consider a 102" steel whip mounted on the rear bumper.

Firestick makes an excellent antenna but all fiberglass antennas have a single wire wound around the fiberglass core and the wire will break if flexed too much and the wire cannot be repaired.

The mount for the antenna must have a good ground for the antenna to work properly. Swing-away tire carriers are usually not grounded very well so if you use the swing-away run a seperate ground wire to the frame.

['Doc]

I think before I bought anything else, I'd hook that SWr meter up and see what that antenna looks like to your radio. I would also advise you to read the instructions with that SWR meter.
I can't honestly say that I think much of any of the 'shorter' fiberglass antennas, but the type of range you say you're getting with yours is not 'normal' at all. That assumes that it's been properly tuned, of course, and no, there are no "pre-tuned straight out of the box" antennas.
- 'Doc

[Dmax5er]

Thanks for the advise guys, as far as a whip, thats is the best choice but not an option on this jeep, i have to keep it as short as possible or tree limbs will knock it off, i was thinking of going with a 5.5 francis or 5' firestik...the jeep has a cloth top but the top is off of the jeep right now so there is about 2/3rds of it above the body. Do you think the cloth top will soak up any signal or does that just pertain to metal?

The antenna is mount on the tire stop not the swing, it has 4 bolts thru the body. And i will ground the body to the frame and see if that helps, but i will do as you say and check the SWR first.

Thanks again guys

[Mikey B]

You'd be hard pressed to "knock" off a 102". I hit alot of stuff with mine, as it measures 14' from ground to tip. The most that has ever happened to it was a bit of a bend, and I straightened it out.

[Dmax5er]

HAHAHAHAHAH, i know you guys are right but i aint puttin a 102 whip on my jeep. besides i dont need something else rubbing a hole in my top...I use to have one on my truck back in the day and that thing was all over then place...

[231]

HAHAHAHAHAH, i know you guys are right but i aint puttin a 102 whip on my jeep. besides i dont need something else rubbing a hole in my top...I use to have one on my truck back in the day and that thing was all over then place...

I agree with Doc. Before you go spending more on antennas, you'd be smart to tune what you have. First off if you've mounted it to the spare tire stop, that means you either have a YJ or CJ. And chances are you don't have a good enough ground if that's all you did is clamp/bolt it on. Your SWR meter will show a VERY high SWR if that's the case. Assuming of course your antenna insulator(s) are installed correctly, the grounding is the other half of your antenna. And through paint isn't typically a good ground. You'll probably need to run a bit of grounding strap from the mount to a shiney metal point on the frame or bumper to improve the ground point. Simply throw some black paint on the ground point when you are done (and things are tuned up and good).

As far as the antenna being 2/3's above, this is true. However, even with the railings on your CJ/YJ you'll see no real reflection or SWR problems even with the top on. Or rather, I never have on any of the CJ/YJ/TJ, or JK's I've done. Both the soft and hard top (fiberglass) materials are invisiblel to RF, and the support rails aren't a problem as long as the antenna isn't touching them. On the hard tops though, it's not uncommon to get reflection if you happen to have a rear defroster. But if I recall you should have enough of the antenna above the tub to work okay with a 4' antenna. A 3' might be questionable though.

And I've mentioned it many times here, but if you wheel your rig (like I do) most clubs and OHV areas have banned the use of 102" SS whips anyway. I have one and run one periodically on my TJ, but not on the trail. I personally prefer the Everhardt Tiger TSM-4' Superflex for wheelin'. All the guys I wheel with that have used Firestiks, K40's, Wilson's etc. have replaced them with the TSM-3' or TSM-4' with terrific results. And no matter what you do, it'll whip around some. Simply install a tennis ball on the antenna where it makes contact with the top. I've done that for years for both my hard and soft tops. Works fine. And if all you want to do is run it on the trail, add a quick disconnect.

Good luck.

[Dmax5er]

HAHAHAHAHAH, i know you guys are right but i aint puttin a 102 whip on my jeep. besides i dont need something else rubbing a hole in my top...I use to have one on my truck back in the day and that thing was all over then place...

I agree with Doc. Before you go spending more on antennas, you'd be smart to tune what you have. First off if you've mounted it to the spare tire stop, that means you either have a YJ or CJ. And chances are you don't have a good enough ground if that's all you did is clamp/bolt it on. Your SWR meter will show a VERY high SWR if that's the case. Assuming of course your antenna insulator(s) are installed correctly, the grounding is the other half of your antenna. And through paint isn't typically a good ground. You'll probably need to run a bit of grounding strap from the mount to a shiney metal point on the frame or bumper to improve the ground point. Simply throw some black paint on the ground point when you are done (and things are tuned up and good).

As far as the antenna being 2/3's above, this is true. However, even with the railings on your CJ/YJ you'll see no real reflection or SWR problems even with the top on. Or rather, I never have on any of the CJ/YJ/TJ, or JK's I've done. Both the soft and hard top (fiberglass) materials are invisiblel to RF, and the support rails aren't a problem as long as the antenna isn't touching them. On the hard tops though, it's not uncommon to get reflection if you happen to have a rear defroster. But if I recall you should have enough of the antenna above the tub to work okay with a 4' antenna. A 3' might be questionable though.

And I've mentioned it many times here, but if you wheel your rig (like I do) most clubs and OHV areas have banned the use of 102" SS whips anyway. I have one and run one periodically on my TJ, but not on the trail. I personally prefer the Everhardt Tiger TSM-4' Superflex for wheelin'. All the guys I wheel with that have used Firestiks, K40's, Wilson's etc. have replaced them with the TSM-3' or TSM-4' with terrific results. And no matter what you do, it'll whip around some. Simply install a tennis ball on the antenna where it makes contact with the top. I've done that for years for both my hard and soft tops. Works fine. And if all you want to do is run it on the trail, add a quick disconnect.

Good luck.

Very good, ill try that, ill check swr before and after grounding, and yes its a 93 with cj front conversion, dubbed the YJ7... Thanks

[AK47Cowboy]

well im no 20 year expert, but ive learned a thing or two lately about the CB world lol. i bought a 2ft Firestik 2 antenna for my Cobra 29 chrome. it had a tune up but nothing fancy. its mounted on a chevy pickup reg cab, on top of roof via magnet mount. SWR is near a perfect 1. anyways........i have had nothing but awesome performance out of my firestik antenna. it picks up extremely well and i have talked out 25 miles with it. i was told again and again the 2ft was too short but shoot fire i cant complain a lick! technically it is too short for the ground plane i have, because on channel 20 my SWR is near perfect 1. on channel one its around 1.3 and on 40 its too high....over 2 but below the red. if im correct that means my antenna is too short for the ground plane. but in reality i only use channel 19 for the road and a few other channels for 4 wheeling. so my SWR is set great from channel 1 to about 35. so for me it works. the 2 footer dont make my truck look like a rolling antenna going down the road and has a sporty look to it. for a jeep or something similar for off roading, as long as u dont rip it off with a tree limb........id never have anything else

['Doc]

Actually, from the numbers you quoted, your antenna is slightly too long. But if it's working for you leave it alone. That length and/or SWR has very little to do with any grounplane as you think. That 'groundplane' isn't just the vehicle's metal body, but includes the 'dirt'/concrete/whatever under it. So you have more 'groundplane' than you think you do. ('Groundplane' is a very misunderstood term, and in most cases, only means the 'other half' of the antenna. I hate that term.)

Short antennas can exhibit a fairly decent SWR and be terrible radiators. If that 'shorty' works great for you then leave it alone! But I'd be very surprised if an antenna closer to a 1/4 w length wouldn't surprise you with how much better it would do.
- 'Doc

[AK47Cowboy]

well like is said, im no expert by no means. All i can say is it performs GREAT! maybe its luck i dunno. but i know i can talk from Alvaton, Kentucky to Oak Grove, Tennesee on a daily basis. And thats roughly 25 miles give or take a mile. That blew my expectations away for a 2 foot firestik. I have a freind who lives the other direction and around 15 miles away, thru rough terrain and a few good sized hills and hollers ( this is kentucky, imagine that) and he can talk to me as well. Im not debating that a longer antenna wouldnt perform better cuz the stats show its true, but for a 2 footer what performance that is !!! i had a cheapo radio shack antenna on before, that was pretty short as well...........but its perfomance was in the dumps. anways yea mr doc ill keep what works for me lol. im sure if i had a big super duty ford duelly id put a antenna longer than i am on it, but it just dont work for a sporty styled truck. and from my experience with this antenna i cant say one bad thing about it. ive read a good antenna system with a decent radio talks 5-10 miles and im talkin 25 on a daily basis consistantly with a barefoot cobra 29 chrome ( peak and tuned no mods). so for a offroader who needs a shorty antenna how can u beat that !!!!!!!!!

[rattlesnake]

Hook the swr meter up and see what it reads and if that antenna dosent work maybe go with a francis antenna its fiberglass or maybe a wilson