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CB question (firestik tuning) (Updated with installed pics)
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Author:  Donkeykong [ Sun Sep 16, 2007 10:38 pm ]
Post subject:  CB question (firestik tuning) (Updated with installed pics)
CB Question:
I just aquired a uniden CB, a firestik and a 12' cable.

I found that my firestik is the kind that you have to "tune" by cutting the length down, I don't see very much change for the better with the SWR, it started out at 3+ (it had an infinity symbol there) and has pretty much remained pegged at infinity.

Just curious if anyone else has a thought on what else to try.

The antenna is mounted to my yakima rack and is grounded with a #22Ga wire to the sheetmetal of my trunk.

I am curious if the 12' cable makes a big difference and is there anything else to mess with?
-Mark
Author:  Fulltimer [ Mon Sep 17, 2007 4:38 am ]
Post subject: 
It could be the cable. Make sure it isn't kinked or coiled. It is also possible that the previous owner cut too much off. Don't use the radio like it is or you will blow it.

Terry
Author:  corwyyn [ Mon Sep 17, 2007 1:03 pm ]
Post subject: 
Fulltimer wrote:
It could be the cable. Make sure it isn't kinked or coiled. It is also possible that the previous owner cut too much off. Don't use the radio like it is or you will blow it.

Terry

Yeah, you might want to try a different antenna since they're cheaper than a radio, and if that doesn't work try new coax. How do you have the antenna mounted?
Author:  skywarn [ Mon Sep 17, 2007 4:58 pm ]
Post subject: 
im kinda worried here.... ive never seen a fire stick that needs to be trimmed... I dont use firesticks because of that reason.. you cant tune them. Im a big fan of the "skip shooter" it has a little "nail" in the end that you can move upp and down to Tune.

If your SWR are not 1:1 DO NOT USE THE RADIO!!!!! you want to chack them on ch 1 then on ch 40 then see what the AVE is on CH 20. DO NOT TUNE ON CH 20 tune only on ch 1 and 40.

reasons for your swr's to be so far off is
bad ground or NO Ground. depending how your ant is mounted in may have a "floating" ground
pinched coax or torn
power (12 volt) getting to your antenna
short in radio
blown "pill" (moto 2879 in back of radio)
bad/loose connect inside radio to ant. output
coax should only be cut in 3ft ie: 3 ft 6 ft 9ft 12ft etc...so if your cable is at 11ft and 10 inches... your swrs will be bad. if you only need 4 ft of cable you run 6 feet.

also try NOT to coil your extra coax on itself. if you have to run it all the way around your car to the ant. then do it that way. by having it in a coil it can and will "bleed over" and cause your swr's to go bad.


hope this helps
Author:  raceinfan [ Mon Sep 17, 2007 6:24 pm ]
Post subject: 
I didn't have to cut my firestick :shock: never even had heard of that :?

mine has the tunable tip I had a heck of a time trying to get it right & FINALY switched to a differant coax an WAALAA it's just about perfect now & NO ground wire was needed
Author:  Hellrasor [ Mon Sep 17, 2007 7:28 pm ]
Post subject: 
With my coax, the end that screws into the back of the CB needed to be soldered. Before I soldered it my SWRs were beyond 3, then I soldered it and it worked like a charm. Also, I added the heavy duty spring to my 5 ft fire stick, that pushed my SWRs way out. I have the adjustable tip, but to bring them down I had to completely remove the screw from the tip. Definatly check your ground either way.
Author:  dirtykj [ Mon Sep 17, 2007 7:56 pm ]
Post subject: 
Firestik also makes the antenna that you have to cut instead of just tuning the tip ... The "RoadPal" for instance is listed right there on the website as "Light-Weight Cut-to-Tune Antenna".
Author:  Donkeykong [ Mon Sep 17, 2007 9:17 pm ]
Post subject: 
I will have to take a picture of my setup. At the moment it's attached via a clamp to my roofrack and I have a ground wire going to some sheetmetal in my trunk. I spoke with tech at firestik and they said that the ground wire is too long, and I don't really have a good ground plane with it hooked up that way which makes my SWR go thru the roof.

Also, they guy explained that a high SWR "trapps" my broadcast signal and it has no where else to go but back into my CB and make something hot and ruin it.
-Mark
Author:  corwyyn [ Tue Sep 18, 2007 3:48 am ]
Post subject: 
Donkeykong wrote:
I will have to take a picture of my setup. At the moment it's attached via a clamp to my roofrack and I have a ground wire going to some sheetmetal in my trunk. I spoke with tech at firestik and they said that the ground wire is too long, and I don't really have a good ground plane with it hooked up that way which makes my SWR go thru the roof.

Also, they guy explained that a high SWR "trapps" my broadcast signal and it has no where else to go but back into my CB and make something hot and ruin it.
-Mark

Yep, right on both accounts. There are some bolts at either end of the roof rails that you could use for a ground, just pop the plastic cover off and take a look. That would cut your ground wire length quite a bit. And for the SWR, yes if it is too high it gets reflected back to the transmission source and can cause an overload of the circuit - end result, dead CB :cry: :(
Author:  Donkeykong [ Tue Sep 18, 2007 6:34 am ]
Post subject: 
Cool, I will have to pop that cover off to see ifI can't get a wire on one of those bolts.

Should I see a more workable SWR with that setup?

My biggest problem at the moment is that I really want a tuneable firestik (the FirestikII or the firefly) and all I can find off of the turnpike (on my way to chicago where I will be for the rest of the week) has been the "cut to tune" firestiks :(

I'll keep looking, I'm sure that in a city as big as chicago there has to be at least one CB shop..... right?
-Mark
(Who will try shortening his ground today)
Author:  tommudd [ Tue Sep 18, 2007 8:48 am ]
Post subject: 
get around most larger truckstops and there will be a CB shop there close by they can sell / install / and tune it for you, may try that also, I would say part of the problem is in the ground
Author:  Donkeykong [ Mon Sep 24, 2007 2:54 pm ]
Post subject: 
First off, thanks everyone for all the help. My CB seems to be working well, Here is my writeup, and parts list should anyone care :)

Alright, so I put in a shorter (from the antenna to the trunk hinge) and beefier (was #24ga, now is #12ga wire ground), and now I have a fatter 18' coaxial cable, and I also managed to find a 4' Firestik II (as opposed to the 3' firestik which was "trim to tune")

With all that said, here is a better breakdown of what I have replaced:
12' coaxial replaced with a 18' coaxial (a little beefier, plus a trucker told me that I would have better results with a 18-21' coaxial versus the 12 footer I had)
3' Firestik Replaced with a 4' Firestik II (make sure that your firestik has the cap off in the packaging, if not it'll sat on the top "trim to tune")
#24ga Ground replaced with #12ga Ground (Mainly because I'm attached to plastic over my roofrack, and it's an unfit ground, so I had to run a cable)

I was getting SWR of infinity (pegged above 3), and now I am getting it as low as 1.75-2 SWR. Also, PILOT stations sell SWR meters cheaper than radioshack ($20 versus $49.95) I wish I had seen that before I got my $50 SWR meter...

I would still like to mount my antenna to my spare tire, but I can't blow $65 + S&H for the kilby one at the moment, so this will do. Other than that I might keep my eyes out for a 21' cable, and maybe even a 7' firestik II antenna once I have it trunk mounted.

Here are the pics: (and yes, it's the 6-speed manual)

My antenna on the jeep:
Image


A close up of the mount to my roofrack:
Image


A shot looking in the drivers side window:
Image


A shot looking in from the passenger side window:
Image

-Mark
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