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4x4Dalton
06-26-2010, 08:57 AM
Hey gang I am installing a Hy-Gain II Cb in my 95. Yeah I know its a Dinosaur CB but for $15 cant beat it. What is the best CB antenna out there now a days? Havent dealt with CB's in a while now. Any help is greatly appreciated.

drakan1908
06-26-2010, 01:17 PM
Firestick is what I have. I ordered mine from Walcott http://www.walcottcb.com/index.php If I had it to do over I would go out to the truckstop in Troutville, Bear, they have a good selection. If a trucker will run it,it is usually a good one. I have a meter to set SWR, let me know if you need to borrow it.

prerunner1982
06-28-2010, 10:15 AM
I have always heard a 102" is the best performer... but typically most people don't want to (or can't) run something that long and can be dangerous on the trail. You will typically hear Wilson or Firestick brand antennas mentioned. I am running a 102" fiberglass whip on my XJ that I got from a Radio Shack.

Mudderoy
06-28-2010, 01:35 PM
I have always heard a 102" is the best performer... but typically most people don't want to (or can't) run something that long and can be dangerous on the trail. You will typically hear Wilson or Firestick brand antennas mentioned. I am running a 102" fiberglass whip on my XJ that I got from a Radio Shack.

A full sized antenna is best. 27 MHz is about 33 feet long. 1/2 wave is 16.5 feet, 1/4 wave is about 8.5 feet (102 inches). Anything shorter must use a loading coil to make the radio's transmitter THINK that the antenna is at least 102 inches long (1/4 wave). Loading coils generate heat and don't receive radio signals very well. So you lose transmission power and reception. The longer your antenna the more signal you can receive.

So basically anything shorter that 1/4 sucks, it just depends how much.

With that said antennas with loading coils (that includes the firestick) work better than NO antenna, and you may see little difference in performance depending on the distance from the station that you are communicating with.

On a Jeep trail, you would be hard pressed to notice a difference talking to someone a mile or less away.

I would say those (4 feet?) fiberglass antennas are about as tough as you can get. Also they are cheap enough to have a spare.

Make sure you mount them away from metal and as high up as possible.

xj4life2
06-28-2010, 08:00 PM
The only problem with the long whips is they are illegal at most off road parks and other areas due to damaging the vehilcle behind you. I run the fire stick but much prefer the base loaded k40

Mudderoy
06-28-2010, 11:37 PM
The only problem with the long whips is they are illegal at most off road parks and other areas due to damaging the vehilcle behind you. I run the fire stick but much prefer the base loaded k40

That's interesting. I have a 102" whip on my Jeep, but that's because a 4' whip won't work on my radio. Actually I built a 3" add on so my antenna is 12' long.

4x4Dalton
07-28-2010, 06:56 PM
Been thinkin of a steel whip from Radio Shack. Have any of ya'll used them?

xj4life2
07-28-2010, 07:47 PM
That's interesting. I have a 102" whip on my Jeep, but that's because a 4' whip won't work on my radio. Actually I built a 3" add on so my antenna is 12' long.

Mabey in TX thats ok but here in Ca its not. I've been to a couple places that actually made you take them off if you wanted to wheel there. I like the steel whips just not practical here. The fact that a 4' ant wont work on yours really puzzles me though, I have never heard of that before.

Mudderoy
07-28-2010, 09:25 PM
Mabey in TX thats ok but here in Ca its not. I've been to a couple places that actually made you take them off if you wanted to wheel there. I like the steel whips just not practical here. The fact that a 4' ant wont work on yours really puzzles me though, I have never heard of that before.

I heard that the other day as well. That 4' loading coil of an antenna is fine for a CB.

jdougn
07-31-2010, 10:00 AM
The local radio guru would say to make sure you 'tune' any antenna to the channels you frequent. My little cheapo antenna wasn't good for much until he tuned it. Now it works great.

Mudderoy
07-31-2010, 10:52 AM
The local radio guru would say to make sure you 'tune' any antenna to the channels you frequent. My little cheapo antenna wasn't good for much until he tuned it. Now it works great.

A lot of people focus to heavily on reflected power (Standing Wave Ratio - SWR). Anything from a 1.7:1 to 1.1:1 is fine. I recommend tuning lowest SWR on channel 20 (not technically the center of the CB band, but close enough). If your SWR is going above 1.7:1 in a mere 40 channels of band width at 27 MHz you have antenna problems (or feed line, or antenna mounting issues).

BlueXJ
07-31-2010, 12:11 PM
Then are you saying that brands don't matter Muddy just SWR factors?

Mudderoy
08-02-2010, 04:19 AM
Then are you saying that brands don't matter Muddy just SWR factors?

Well what I was talking about was people's over concern about SWR measurements. Every antenna will have a SWR regardless of brand. I like brands but mainly from the stand point of consistency and proficiency of design.

XJ4IV
08-04-2010, 09:35 PM
ummmm that al being said I use a 48" firestick that I got from a radio guy in north dallas... he tuned it for me and it works great... I told him I wanted a strong antenna that would hold up to offroad abuse... and hoenstly I have put mine through hell and back ask ANYBODY who has wheeled with me everything above my roofline is totally abused and NONE of it has damaged I even once forgot about the antenna and pulled into a carport and had the stick hang up and when I went to back up it bent like designed to do and whipped back into form... I think my firestick is pretty dang good for 18 bucks

bluedragon436
10-25-2010, 06:36 AM
Yeah I don't get it... Apparently hams are allowed to have whatever ant. setup works for the rig... but CB's can't??!! I don't know, doesn't make any kind of sense to me.. I just know that he got a few tickets on different occasions for his ant, being too long and a danger to bystanders... which is kind of funny, since he always has the end tied down to the front of his Jeep, not up in the air and whipping around where it'd be dangerous... Kind of confusing to me... Most of them, I've noticed have the loading coil (or whatever you want to call it) at the bottom, and their ant, aren't too crazy long, but have seen a few of the long ones..

Mudderoy
10-25-2010, 11:53 AM
Yeah I know I will be running a firestick when I build my comm setup... as I have seen them go through some abuse... My step father had dual firesticks on his big rig, and never had any issues with them performance wise, and even after he was involved in a huge accident that involved the truck being rolled on its roof, and bending the heck out of the ant., he was able to pull them off, and install them on his new rig with no issues to performance or looks..

I think people should consider what they would do if they were alone and were in a roll over. Keep in mind that this can happen even when you are not off road. I think a mag mount antenna stowed in the back just might be a life saver.

bluedragon436
10-26-2010, 08:17 AM
You mean to keep as a spare, or to use a mag mount??? I would think maybe having a mag mount as a spare might not be a bad idea...

Mudderoy
10-26-2010, 09:28 AM
You mean to keep as a spare, or to use a mag mount??? I would think maybe having a mag mount as a spare might not be a bad idea...

As a spare. A mag mount will stick to the top, or bottom of your rig. :D

bluedragon436
10-26-2010, 12:01 PM
Yeah I hear that... keep some long coax... in case you need to climb a tree.. LOL.. just one more reason to now wheel alone... that way you can throw you mag mount on the bottom or side of Jeep after you have managed to roll it, and call your partner back, or up if you were ahead of him... I'll def. be behind on my outings....

Mudderoy
10-26-2010, 01:03 PM
Yeah I hear that... keep some long coax... in case you need to climb a tree.. LOL.. just one more reason to now wheel alone... that way you can throw you mag mount on the bottom or side of Jeep after you have managed to roll it, and call your partner back, or up if you were ahead of him... I'll def. be behind on my outings....

Mobile antennas require a ground plane. Putting a mag mount in a tree would cause very little RF energy to flow out of the antenna. The majority of it would be reflected back to your radio. This can burn out the final transistors making your emergency situation worse.

When you put the antenna on a metal surface it doubles the "electrical" length of the antenna.

bluedragon436
10-26-2010, 01:54 PM
OH yeah... didn't think about that part... I'll just stick with hoping I don't need to use it, but if so will stick it to the bottom of my Jeep somewhere if needed... will def. be picking on up once I start hitting the trails...

bigjim350
10-26-2010, 09:11 PM
I use a Wilson 5000 magnet mount, with a 3' tunable anttena, and love it.

bluedragon436
10-29-2010, 10:45 AM
I thought about running a magnet mount as a permanent ant. mount for my setup once I start building mine... guess I should start that build soon, as I may need it more often wheeling in a completely stock XJ... then again I can't go too far into trails that my cell won't work for now I guess..

Mudderoy
10-29-2010, 12:00 PM
I was very impressed with the K40 I had on my old blue truck years ago.

I had it mounted on the roof and since it was a twist on/off, I could just open the sliding back glass reach up and quickly disconnect it and sit it next to me in the truck.

I had to do that anytime I went into a drive through. 4" lift and 36.5 tires of a full sized chevy swb.

bluedragon436
10-29-2010, 02:58 PM
Nice.... Yeah I think that is one thing I like about the magnet mounts is that they will detatch themselves and not break something if they do get caught up on a low branch or something... well might scratch the paint... but better than breaking the mount or the ant.

4x4Dalton
10-30-2010, 06:11 AM
So far I have been using a Radio Shack Weather Band magnet mount style and have no trouble as of yet. Seems like a good one,picks up great here.

bluedragon436
10-30-2010, 07:55 AM
Yeah I think I will look into collecting everything together once I get my lift, rims/tires taken care of... might just look into a mag mount for now if nothing else... can always upgrade at a later date, and keep the mag mount as an emergency spare...

Jeepster19
11-01-2010, 08:30 PM
I have used a 102" stainless steel whip from radio shack,they work great!Also used a wilson magnetic mount,good also.As far as the 102" fiberglass whip goes,it works but is not even close to a stainless steel whip in clarity.Just think,you can use your 102" stainless steel whip as a bream buster,works great!!!Oh yeah,cheaper&more durable than a real bream buster!!!:thumbsup::D

SGT ABN XJ
11-24-2010, 08:27 PM
Thanks for this thread, there is some good knowledge and experiance here.
I run a magnet mount right now but am going to give the 102 whip a try to see if my radio gets any clearer..

Mudderoy
11-24-2010, 08:49 PM
Thanks for this thread, there is some good knowledge and experiance here.
I run a magnet mount right now but am going to give the 102 whip a try to see if my radio gets any clearer..

An antenna will only change signal strength. That's assuming the antenna, feed line, and radio are properly matched. Also known as SWR.

bluedragon436
11-25-2010, 09:38 PM
Yeah that is one thing that I have been very lucky with over the years.... that I have had no issues with my CB setups performance without making any changes... but after doing some research, will def. make sure I check my SWR and make necessary adjustments... before I take a chance of ill performance or damage to my radio..

Bbasso
09-18-2012, 01:16 AM
If I could get an opinion about my very simple setup, I would appreciate it.
A recently purchased Cobra 19 ultra iii and my 8-10 year old Hustler IC100S Mag Mount CB Antenna With Spring.

I'd like to keep the magnet mount for ease of everything and with 15ft of wire it's mounted on the roof before the rear hatch.

thanks

prerunner1982
09-18-2012, 10:15 AM
Being a mag mount it would be best to put the antenna as close to the center of the roof as possible.
Your choice of radio is fine, I have a couple of the Cobra 19s as well. I would suggest hard wiring it as it needs constant power to keep the channel memory. If it is on a switched power source it will revert to channel 1 or 9 or some random channel every time you turn on the vehicle.
Is the coax new or has it been around as long as the antenna? If it is old as well it would be a good idea to check the SWR to make sure you don't have any shorts in the coax. Even if the coax is new, it wouldn't hurt to check the SWR anyways just to make sure.

Mudderoy
09-18-2012, 10:40 AM
I recommend always wiring bi-directional communications radios directly to the battery.

Mag mounts are fine, but I prefer a perm mounted antenna, especially for off road. A mag mount is a great spare, emergency antenna though.

NW99XJ
09-18-2012, 11:25 AM
I'm surprised there hasn't been much mention of spring mounts here.
I personally swear by my spring mount. It's probably saved my antenna, and/or fender mount bracket more than a few times from certain disaster offroad. Granted, it's also caused my pre-tuned 4' fiberglass stick to come and whack the side of the jeep, hood, or occasionally the windshield. but even with that i'm happy with its performance. I checked the SWR once after install, and again about a year later... So far, i'm still sitting good. No complaints.

Mudderoy
09-18-2012, 11:33 AM
I'm surprised there hasn't been much mention of spring mounts here.
I personally swear by my spring mount. It's probably saved my antenna, and/or fender mount bracket more than a few times from certain disaster offroad. Granted, it's also caused my pre-tuned 4' fiberglass stick to come and whack the side of the jeep, hood, or occasionally the windshield. but even with that i'm happy with its performance. I checked the SWR once after install, and again about a year later... So far, i'm still sitting good. No complaints.

Old picture...
http://muckleroy.com/images/jeep_ant4.jpg

prerunner1982
09-18-2012, 11:35 AM
http://www.xjtalk.com/picture.php?albumid=211&pictureid=3229

Bbasso
09-19-2012, 09:33 AM
Yup, mine has constant power, so for camping and such I can have it on and not leave the key in also keeps the last station in memory.
I have no clue how the coax cable's condition is, it's been around a while and not removable from the antenna.
Is there a way to check the SWR without a meter? ( I doubt it) I don't know of any local CB shops near me... Everything is big box stores with no knowledge or care.
As for the placement of my antenna, While it's far back it is on the roof (good) but with not willing to drill holes this was the best place for running the short 15ft wire.

prerunner1982
09-19-2012, 10:06 AM
When I was running a mag mount I mounted it in the middle of the roof and then ran the coax through the driver's side next to the B-pillar. This is really only a temporary set up and pinched the coax pretty bad.

Jeepincamper
09-24-2012, 08:36 PM
I use to have a 7' firestick. I used it on my old `69 Catalina and on my `79 CJ7. It was killer. I really got out and could hear everything. It was rather directional on the CJ as I had it mounted on the spare tire bump stop. My best signal was across the left front fender. The Catalina made an excellent ground plane. Still, it was strongest across the front, but could do okay off the back as it was a trunk mount, then a ball mount. All good. I used a Francis Gray Ghost on my CJ7. It was a 108" fiberglass whip. It worked almost as good as the fire stick, but was much better for wheeling, as the conductor was in the core. Thus, protected from tree branches. K40's work well and the magnets are killer strong. If you can find RG8 Superflex, that is great coax for wheeling. It has a strainded conductor. Has the same properties as RG8, but only slightly large in diameter than RG58. Hard to find. But, worth it.
My favorite mobile was a Cobra 148 GTL SSB. I have an Lafayette LMS 40. I blew the finals. Killer modulation. My base is a Courier Centurian Dwight D. A totally awesome radio, especially with the D104 Mic.

Jeepster19
09-28-2012, 08:43 PM
Been thinkin of a steel whip from Radio Shack. Have any of ya'll used them?

They work great,I've bought several 102" stainless steel whips from them.I must tell you there is no comparison in clarity when it comes to the 102" stainless steel whip.Me and a friend of mine compared a 102" fiberglass whip to a stainless,not even close on clarity.He lived up the road about 8 miles.I once had a 102" stainless steel whip mounted to the roof of my 81 Datsun 310 hatchback,that thing would blow smoke son!I know,redneck but I didn't care,it was bad to the bone!:D:D:D

92warwagon
11-19-2014, 10:04 PM
thanks good info

downsy
11-21-2014, 01:21 AM
HAM (VHF/UHF) is where it's at. But I do sport both types of radios. On my CB side I run a Firestik antenna. I have two different ones. One a 3 foot and the other is a 4 foot. On my last XJ I ran a 102 inch stainless whip. Worked great.

After switching to HAM bands I wouldn't go back unless others in the group run a CB. The HAM band are simply much better for our needs.

prerunner1982
11-21-2014, 09:50 AM
The HAM band are simply much better for our needs.

I run both and agree...

Mayooo
11-24-2014, 10:39 AM
Oh man! I could talk about this for hours.. Radio is one of my hobbies. And I've built a lot of antennas.. On my xj I run two. One is a 102" stainless whip and the other is a antron99 that is mounted on a 10' telescoping mast mounted to my roof rack. That folds down for transportation. The a99 is a 16' antenna. Of corse I'm parked when im running that one. I like to drive up to mountain tops and make contacts around the world.

Mudderoy
11-24-2014, 01:27 PM
The BEST antenna is going to be the one mounted properly and a full wave length of the operating frequency. With a proper ground plane that would be 1/2 half of the wave length with the other half reflected.

468 / frequency, 468 divided by 27.200 = 17.205882 feet. So for about the middle of the CB band your antenna would need to be 17+ feet long.

Assuming the best radiation pattern is circular, which is usually what you want in mobile operations, the mounting point would be on top in the center mass of all the metal.

Now add the height of your vehicle to that 17' :D

Shorter antennas are compromises. A FireStick is a compromise and will not, and never will, work as well as a full wave length antenna, 1/2, or 1/4.

Where you mount the antenna is another compromise that affects the reflected power back into your transmitter, radiation pattern, and what signals you can and can't receive.

I mounted my 102" whip on the rear pass quarter panel which means my radiation pattern should be forward and slightly left. Now I can aim my Jeep in the direction I need to hear and be heard.

Chickasaw
07-22-2015, 10:11 AM
I work on CB's a little on the side. Got my electrical engineering degree (AAS) not to long ago. 102" whip antennas are the best antenna to go with. They are flexible but mostly they seem to be extremely easy to tune. On every setup I have done so far, the SWR meter was already set perfectly unless I ran into someone with a bad ground or cable. The antenna "can" be bent over the vehicle and "tied" to the other side to lessen the height until you are back on the street again.
SWR readings need to be checked and the antenna adjusted or else you will find you burned up a component inside your expensive radio that will take you 3 weeks (or more sometimes) to arrive from China or wait for a tech to wait on it from China. I decided to stop peaking from behind my door in here to post this because there seems to be a lot of folks who don't understand you can't just take the antenna out of the package and hook it up and go. Cable length WILL change SWR readings as well as having your door open while trying to adjust your antenna.
Firestik pretty much explains everything on their site
http://www.firestik.com/Tech_Docs.htm

It is better to have a cheap radio with a good antenna than an expensive radio that no one bothered to adjust the antenna on.
I am passionate about electronics so this post could EASILY turn into a novel but I wanted to say a couple things hoping to help someone with troubleshooting their CB. The main two items is adjust your antenna for the SWR (standing wave ratio) and be CERTAIN to ground that antenna with a solid contact. I lightly grinded the location I placed my antenna and all of sudden I was YELLING at folks :)
OH! One last thing, there is usually a plastic piece on the antenna that looks like a plastic washer. Your antenna is positive and negative. Please don't remove that little plastic washer. It prevents your + and - from touching each other shorting your antenna which is another way to burn up your radio.
I don't know everything about CB radio's....yet, but I plan on it when I grow up someday. :)
Peace

Chickasaw
07-22-2015, 10:17 AM
Mag mounts are made for temporary installations. You can use it as a permanent antenna but be aware of future ground issues.
http://www.firestik.com/Tech_Docs.htm

Chickasaw
07-22-2015, 10:26 AM
I'm surprised there hasn't been much mention of spring mounts here.
I personally swear by my spring mount. It's probably saved my antenna, and/or fender mount bracket more than a few times from certain disaster offroad. Granted, it's also caused my pre-tuned 4' fiberglass stick to come and whack the side of the jeep, hood, or occasionally the windshield. but even with that i'm happy with its performance. I checked the SWR once after install, and again about a year later... So far, i'm still sitting good. No complaints.

The spring will change SWR readings for those who don't know. If your spring mount is perfect and you take the spring off it will have bad SWR readings. That spring adds to the overall length of the antenna so those who choose a 102" whip that find the antenna needs more length can try adding a spring to see if it improves SWR readings.
I really hope I helped someone...

Chickasaw
07-22-2015, 10:40 AM
If I could get an opinion about my very simple setup, I would appreciate it.
A recently purchased Cobra 19 ultra iii and my 8-10 year old Hustler IC100S Mag Mount CB Antenna With Spring.

I'd like to keep the magnet mount for ease of everything and with 15ft of wire it's mounted on the roof before the rear hatch.

thanks

Old thread but new people like me read them. :)
If you use a magnet mount, center it on your roof. Your vehicle is the ground plane and without a decent ground plane you probably won't be satisfied with the performance of your radio. Putting it at the back of your roof gives you less ground plane. Basically making your antenna unidirectional or...let's see how to better explain this...making you point it mostly one way.

Use a SWR meter to check if the length of your coax is a problem. If the SWR settings on channel 40 are higher than on channel 1 you need to shorten your antenna.
Here is a link to Firestik explaining this in terms in such a way that you don't need to get a degree to understand it.

http://www.firestik.com/Tech_Docs/Setting_SWR.htm

Cheers!

prerunner1982
07-22-2015, 10:47 AM
Use a SWR meter to check if the length of your coax is a problem.

Length of coax is never a problem. I assume you mean length of antenna?

bluedragon436
07-22-2015, 11:07 AM
Going a bit higher on the new Firestik antenna I'm ordering, as well as a new coax, just in case the current coax on my setup is the issue... I cannot however go with a 102" whip, as they are illegal in DE apparently, cause I have a friend who has one on his XJ, and he got a ticket for it... and it was tied down to the front of his rig, but still got a ticket... so going with a 5' Firestik instead of the 4' Radio Shack special I had.. since I was having a SWR tuning issue with my setup... Tried to grind the mounting points to give it a better ground connection, but for some reason the SWR got worse... so going to try and replace the ant, with a better one, and a new coax, in case that was the issue for some reason...

Chickasaw
07-22-2015, 11:25 AM
Mabey in TX thats ok but here in Ca its not. I've been to a couple places that actually made you take them off if you wanted to wheel there. I like the steel whips just not practical here. The fact that a 4' ant wont work on yours really puzzles me though, I have never heard of that before.

Maybe the antenna was dysfunctional.
The plastic washer mentioned in another post separating the-/+ could have been missing shortening the antenna.(Believe it or not a LOT of people remove that while installing antennas for some reason. I just scored a NICE Cobra 29LX/LE WITH the dual coil antenna for pennies because he fried the CB by taking that out.) I am honest, I explained it to him FIRST but he didn't want to deal with it. CAMO TOO! Repaired with $3.

The antenna could have had a very weak or no ground. I installed mine on the toolbox of my pickup and my SWR was awful! Couldn't be heard within a half block. The hole I drilled to mount it left microscopic shards of metal and my godson and I kept tightening the antenna until it should have broke with no luck. I kept telling him the readings kept pointing to a ground problem. We even tried a different meter. Finally I asked him to just take it off to try my oil cooled antenna and THAT'S when he saw the tiny metal (I am vision impaired). He smoothed it with the grinder and I talked to him for 14 miles before he couldn't hear me. No amp or linear. I did however "peak" the radio just a bit. No add ons inside.

Location, location, location. Where was it mounted? I have seen some antennas mounted on the side of the pickup bed and on the bumpers on one corner of Jeeps, in the rear. It is recommended you use at minimum 8 ( or is it 9?) foot of coax for efficient use. I am going to use a quote from Firestiks site about bumper mount:

"When you key down on the microphone button the antenna needs to absorb the energy and radiate it outwards through free space. The radiation field on wire wound antennas is relatively weak at the bottom but as it moves upward, the field strength increases dramatically. This characteristic is the primary reason why wire-wound antennas are such efficient radiators … specifically because the highest point of the antenna generates the highest concentration of energy. There in lies the problem when bumper mounts are used on SUV's and other vehicles with tall parallel surfaces (trucks with campers, etc.). The highly reactive portion of the antenna is not in free space. We see it all of the time and it almost always results in a high SWR condition."
Here is the link:
http://www.firestik.com/Tech_Docs/Bumper-mnts.htm

Basically the top of your vehicle, which should be the bottom of the antenna, distorts the waves coming from your antenna. Make sense? Sorta? Maybe? Lastly, be sure to tune your SWR away from standing objects and close your doors. No trees, houses, or big metal barns that look like aircraft hangars like my friend Marc has on his farm.

Chickasaw
07-22-2015, 12:06 PM
I have used a 102" stainless steel whip from radio shack,they work great!Also used a wilson magnetic mount,good also.As far as the 102" fiberglass whip goes,it works but is not even close to a stainless steel whip in clarity.Just think,you can use your 102" stainless steel whip as a bream buster,works great!!!Oh yeah,cheaper&more durable than a real bream buster!!!:thumbsup::D

Those 102" steel whips are great. I have a double coil on my pickup. I use the 102" steel in my attic and made my own ground plane. My home base radio skips from FL to TX with it. I aimed my ground plane that direction so not too bad from OK near the KS border to all the southern states. No Amp.
My Jeep doesn't lock ( little by little I fix her up) so, so far I haven't gotten to mount a CB and antenna but I think I will experiment with the whip on it since I read it has a unibody. (Jeep XJ). The unibody is AWESOME for mounting an antenna but in order to use the entire Jeep as a ground plane I either mount a coil in the center of the roof (rather not), OR bend a whip from the bumper or hatchback top and bend it across the top to "tie" to the front bumper. I haven't researched that yet or tried it but if I find success I'll post again in the future.

Then there is my other half's Toyota which seems to be made of styrofoam. I'll post final results on that also for anyone who may have a newer model made of mostly fiberglass so if I get it figured out maybe it will help someone. The Toyota is an SUV. My magnet doesn't stick hardly ANYWHERE on it. I'm not sure but it seems I may have to MAKE a ground plane on that one. I'll come back in here to explain it as soon as I get that one installed and tuned also.

All I know is that 20 years ago a trucker at a weigh scale had a linear and keyed up and fried my radio. I had just bought it 2 days before. I went to school 3 years ago and just fixed that radio and I refuse to have anyone fry my final transistor again or fry it myself because the SWR is not right.
The 102" stainless whip has so far been the easiest antenna to deal with. SWR readings seem to always come out well. If you're going to insist on buying an antenna and hook it up with no tuning I recommend the whip. Seems to be a lesser chance of damaging your radio.
Cheers!

Mudderoy
07-22-2015, 12:18 PM
Coax length shouldn't matter, except shorter = less loss of transmit power and receive signal strength.

If changing the length changes your SWR you have other problems, or it's lying to your meter.

If you look it up online make sure you only read information from an electrical engineer, or a amateur radio operator. I've found you'll get misleading information most often from someone who's only background is CB.

There ARE circumstances where you can use specific lengths of feed line to match the impedance of the antenna, but it would be extremely rare in a mobile CB installation.

Chickasaw
07-22-2015, 01:26 PM
Coax length shouldn't matter, except shorter = less loss of transmit power and receive signal strength.

If changing the length changes your SWR you have other problems, or it's lying to your meter.

If you look it up online make sure you only read information from an electrical engineer, or a amateur radio operator. I've found you'll get misleading information most often from someone who's only background is CB.

There ARE circumstances where you can use specific lengths of feed line to match the impedance of the antenna, but it would be extremely rare in a mobile CB installation.

No. A coax that is too short or too long can and will mess up your SWR readings. Winding your coax will also mess up your antenna settings. For example, you should have at least 1 foot of coax between your SWR meter and radio. A friend thought he would use less and it distorted his readings. My cable from the attic to my home base was wayy too long and my SWR readings showed it. Once I shortened it I was able to get correct readings AND those folks in the south were talking to me.

Your coax is a continuation of your antenna. That is part of where the full wave, 1/2 wave, 1/4 wave and all of that come into play. Eighteen foot of coax is the minimum recommended for installation in a vehicle. I tried a shorter coax and my SWR went to total crap so I zig zagged the 18 foot and all was well. if you must cross your cable do it at 90 degrees. any "twisting" will mess up your SWR. Also, If you must cross your coax with other wires try to cross them at 90 degrees. You know that engine noise you hear in your CB as you accelerate? It can be stopped many ways but I simply ran my coax at 90 degrees from all other electrical wires. Did the same with my power cord.

Gotta go for now but Ill be back soon as I can to check on thread. :)

Chickasaw
07-22-2015, 01:28 PM
No. A coax that is too short or too long can and will mess up your SWR readings. Winding your coax will also mess up your antenna settings. For example, you should have at least 1 foot of coax between your SWR meter and radio. A friend thought he would use less and it distorted his readings. My cable from the attic to my home base was wayy too long and my SWR readings showed it. Once I shortened it I was able to get correct readings AND those folks in the south were talking to me.

Your coax is a continuation of your antenna. That is part of where the full wave, 1/2 wave, 1/4 wave and all of that come into play. Eighteen foot of coax is the minimum recommended for installation in a vehicle. I tried a shorter coax and my SWR went to total crap so I zig zagged the 18 foot and all was well. if you must cross your cable do it at 90 degrees. any "twisting" will mess up your SWR. Also, If you must cross your coax with other wires try to cross them at 90 degrees. You know that engine noise you hear in your CB as you accelerate? It can be stopped many ways but I simply ran my coax at 90 degrees from all other electrical wires. Did the same with my power cord.

Gotta go for now but Ill be back soon as I can to check on thread. :)

I forgot to add that I have an AAS in electrical engineering. Trying to figure out how to get my bachelor. I don't know it all but I will someday. :)

Mudderoy
07-22-2015, 01:34 PM
No. A coax that is too short or too long can and will mess up your SWR readings. Winding your coax will also mess up your antenna settings. For example, you should have at least 1 foot of coax between your SWR meter and radio. A friend thought he would use less and it distorted his readings. My cable from the attic to my home base was wayy too long and my SWR readings showed it. Once I shortened it I was able to get correct readings AND those folks in the south were talking to me.

Your coax is a continuation of your antenna. That is part of where the full wave, 1/2 wave, 1/4 wave and all of that come into play. Eighteen foot of coax is the minimum recommended for installation in a vehicle. I tried a shorter coax and my SWR went to total crap so I zig zagged the 18 foot and all was well. if you must cross your cable do it at 90 degrees. any "twisting" will mess up your SWR. Also, If you must cross your coax with other wires try to cross them at 90 degrees. You know that engine noise you hear in your CB as you accelerate? It can be stopped many ways but I simply ran my coax at 90 degrees from all other electrical wires. Did the same with my power cord.

Gotta go for now but Ill be back soon as I can to check on thread. :)

That's a negative ghost rider. What your talking about here is a common misconception, that's why I thought I better post and correct it.


As was stated above coax length doesn't matter if the coax is matched to a 50 ohm impedance (antenna). If the antenna impedance isn't 50 ohm then a 1/4 wave length of coax inverts it. Meaning if the antenna has an impedance greater than 50 ohms then the other end will be lower than 50 ohms. If the coax is 1/2 wavelength (or multiples of a 1/2 wavelength) then the impedance at one end will be the same as the other. Meaning if the impedance at the antenna end is 75 ohms then the impedance at the other will be 75. Manufacturers used this to help CB's tune their antennas. By making the length of coax 1/2 wave length at CB frequencies an SWR meter placed at the radio end would give a correct indication of the match between the coax and the antenna. If the coax is not 1/2 wave length long and the antenna is not 50 ohms the coax will transform the impedance and the SWR meter will not indicate the true SWR. Old wives tale: Changing the length of coax changes the SWR. If you change the length of coax and the SWR changes it only indicates a change in the voltage of the standing wave at that particular point. SWR along a length of coax doesn't change but the voltage measured at different points will thus cause the meter to show different SWR readings.

Ahhh now I'm remembering. Yes if you have an impedance mis-match probably on either end of the coax then varying the length of coax will help match the transmitter or the antenna. If you're using a 50 ohm radio with a 50 ohm antenna then your coax should be 50 ohm and can be any length. It should be invisible to the transceiver and NOT part of the antenna.

prerunner1982
07-22-2015, 01:57 PM
If you have to change the length of the coax to adjust the SWRs you are tuning the coax not the antenna and doing nothing more than tricking the meter. Your antenna is not anymore efficient than it was before.

Also 18' of coax is a myth. The length of the coax is not dependent on the frequency. That's like saying you need a certain length of hose for a certain PSI or a certain length of wire for a particular wattage.

I can feed multiple antennas with the same length of coax with no issue, why? Because the antennas are tuned properly. You only need to use the length of coax necessary to go from the radio to the antenna.

In fact SWR should be checked AT the antenna but in most cases that is not feasible.


Also, coiled coax is not bad either. It is called a choke and prevents stray RF from running down the shield of the coax. In fact these are used quite often in Amateur radio and are often called "ugly baluns" though not really a balun.

Mudderoy
07-22-2015, 02:02 PM
Oh I like this one better...


I was told the same thing back in the ‘60s about the length for a car transceiver should be 18’ (if I remember correctly, or maybe 16’). But an amateur radio operator said it don’t matter if the antenna is properly tuned. We did some experimenting and he was right. Just as jhooten posted above. We connected a badly detuned antenna to the same transceiver and changed the length of the coax. Bingo, different lengths showed different SWR readings. As far as jumper coax he did say that the average jumper should be about 36”; but dependent on the transmitting frequencies. I don’t remember how he explained that formula for jumpers, but he expressed that 36” should allow for placement of the SWR meter and other equipment.
As far as co-phased antennas went, we never got into that; but I do remember many stating that the length matters and that you had to use 2 different coax, (I think one was 50 ohms and the other was 75 ohms).
So all I do is use GOOD coax as short as physically possible with a properly tuned antenna.

Chickasaw
07-23-2015, 12:29 AM
Yup, mine has constant power, so for camping and such I can have it on and not leave the key in also keeps the last station in memory.
I have no clue how the coax cable's condition is, it's been around a while and not removable from the antenna.
Is there a way to check the SWR without a meter? ( I doubt it) I don't know of any local CB shops near me... Everything is big box stores with no knowledge or care.
As for the placement of my antenna, While it's far back it is on the roof (good) but with not willing to drill holes this was the best place for running the short 15ft wire.

I don't seem to be one taken seriously in this thread but because I know things learned in college I will throw this out there for the wolves to attack.

In the old days before there was equipment that checked SWR readings, light bulbs were used. The old timers pit them at the end of the antennas and keyed up and the bulb would light up. These are not magnetic waves. They are Nikola Tesla's standing waves. If I remember right the bulb does not have to be connected TO the antenna. Just near it. The bulb brightness and dimness explained what your power readings were doing which helped "tune" your antenna.

Google it to see how it was done because If I explain it, I might be told I don't know what I am talking about so I'll let you do the research.
Good luck!

Mudderoy
07-23-2015, 12:47 AM
I don't seem to be one taken seriously in this thread but because I know things learned in college I will throw this out there for the wolves to attack.

In the old days before there was equipment that checked SWR readings, light bulbs were used. The old timers pit them at the end of the antennas and keyed up and the bulb would light up. These are not magnetic waves. They are Nikola Tesla's standing waves. If I remember right the bulb does not have to be connected TO the antenna. Just near it. The bulb brightness and dimness explained what your power readings were doing which helped "tune" your antenna.

Google it to see how it was done because If I explain it, I might be told I don't know what I am talking about so I'll let you do the research.
Good luck!

No attack just providing alternative information along with some posts supporting the information I was giving.

Chickasaw
07-23-2015, 02:37 AM
No attack just providing alternative information along with some posts supporting the information I was giving.

Now I had a long explanation as a reply but the forum kicked me out I guess because I took too long.

I'm not going to bother retyping all of that.You have been kind since I have been a member so I will just go back to the shadows and enjoy good reads.
Let it be known that I DO have an Associates in Electrical Engineering and understand radio propagation well, along with a million other things necessary to graduate, such as process control. PLC programming, robotics, sensors and troubleshooting, C+ programming, Digital/Analog, Physics, Ohm's, and everyone else's laws, Mosfets, through hole and surface mount circuitry, AC/DC, logic controllers, hydraulics and pneumatics, and a list too large to mention.

I have mentioned this only to show I have not just had my head filled full of mush but instead I experimented on these things myself and the coax is part of the length of the antenna. No one has to believe me. Just like you, I only came to help but no one will "get it" until they tune an antenna then hook up a different length coax.

If your antenna is not tuned, eventually that final transistor is gonna fry whether you like it or not. Can't tune a whip unless you add to it or cut it off. The only other way is to adjust the length of your coax. Been there.

I will just leave it alone now and keep what is in my head, in my head. It's late and I need to post this before the ether eats it.:D

Happy muddin' everybody!:xj-red:

Chickasaw
07-23-2015, 02:44 AM
No attack just providing alternative information along with some posts supporting the information I was giving.

I put links to everything I was trying to say on Firestiks website. They explain it ALL and in laymans terms. If you want facts installing an antenna go check out their FAQ's. They do a FINE job of explaining do's, dont's, why's and why nots. Don't take my word. Go see what the pro's say. It's to the point.
PEACE!

Mudderoy
07-23-2015, 06:53 AM
You know I bet we're both saying the same thing.

If the antenna impedance ISN'T 50 ohms (or not the same as the transmitter and feed line) then changing the coax length will change the SWR, although it's not doing anything for you but fooling the transmitter, like a tuner does.

Found this on http://www.k0bg.com/

Coaxial Myths

Coaxial myth one: Several antenna manufacturers suggest using a specific length coax cable between the transceiver, and the antenna. Or, they suggest using an open stub cut to some length. Both of these schemes are SWR patches, not fixes. Shunt matching is the only correct way to match a remotely tuned HF mobile antenna to 50 ohms. If you read the article, you'll know why.

Coaxial myth two: Using the best grade of coax money can buy, will be worth the expense. Not! There are two aspects of this myth. First, the the length of coax used in the average mobile installation, seldom exceeds 10 feet. Thus the difference between say RG213, and RG8X, is less than .25 dB! Ah, but there is a hidden facet as well! As mentioned above, it is very important to properly choke off common mode currents from coaxial feed lines, especially mobile ones. In order to duplicate the common mode choke shown at right (7 turns, 3/4 inch ID, mix 31 split bead, ≈2.2 kΩ @ 10Mhz) on RG213, would require 49 similar split beads. That's about $250 worth, instead of just $5! By the way, serial bead chokes tend to be mostly inductive, rather than mostly resistive over their bandwidths, which reduces their common mode effectiveness.

The Article
Matching a mobile antenna to the requisite 50 ohms is a requirement for several reasons. For example, modern solid state radios are designed to reduce their output power when the input SWR reaches ≈2:1. Some will handle a little more, some a little less. Once matched, the SWR doesn't have to be flat, so anything below 1.6:1 is close enough. Remember too, if the unmatched input impedance of your antenna, is less than 1.6:1 at resonance, you need a better antenna and/or mounting scenario.

One very important point needs to be mentioned before proceeding. If you're using a remotely controlled HF mobile antenna like a Scorpion, the motor leads (and reed switch leads if used), and the coaxial feed must be properly choked. If they're not, you'll have terminal problems, and that's no pun! If you don't understand why choking is so important, read these articles: Antenna Controllers and Common Mode.

Further, improper choking of the motor leads will also affect the input impedance of your antenna. Therefore, the motor leads should be disconnected at the antenna before attempting to adjust any matching method. Once matched, if reconnecting the motor leads changes the matching point and/or SWR (no matter how small the change is!), it is a good indication that the motor lead choke impedance is too low.

Antenna manufacturers often tell their customers to cut their coax feed lines to a specific length in order to get a good match. All this does is mask the problem, by moving the SWR node to a different position along the feed line. While this may appear to fix the problem, it doesn't fool most automatic controllers. The truth is, if the antenna is properly matched, it doesn't make any difference how long (or short) the feed line is.

In the following sections, it is necessary to know the exact resonant point (X=Ø) of the antenna we're trying to match. This fact alone, should not infer that exact resonance is a requirement; it isn't! Rather, in this case, it is only a means of arriving at the end point (wide-band match). Once the matching is complete, whatever the SWR is (assuming it is under ≈1.6:1) is irrelevant.

It should be noted that solid state transceivers can generate excessive IMD levels (the FCC mandated ones) when the SWR is over 1.8:1 or so—yet another reason to properly impedance match antennas. While most mobile operators seemingly don't care about IMD, they should! Especially so when using an amplifier which amplifies the IMD along with everything else. In other words, garbage in, garbage out!

Hang in there, nothing like a good argument as long as respect is maintained! ;)

Mudderoy
07-23-2015, 08:32 AM
Going a bit higher on the new Firestik antenna I'm ordering, as well as a new coax, just in case the current coax on my setup is the issue... I cannot however go with a 102" whip, as they are illegal in DE apparently, cause I have a friend who has one on his XJ, and he got a ticket for it... and it was tied down to the front of his rig, but still got a ticket... so going with a 5' Firestik instead of the 4' Radio Shack special I had.. since I was having a SWR tuning issue with my setup... Tried to grind the mounting points to give it a better ground connection, but for some reason the SWR got worse... so going to try and replace the ant, with a better one, and a new coax, in case that was the issue for some reason...

Wow that sounds about as dumb as the cutting barbed wire law we have (had?) in Texas. Wait! Are you sure about this? I mean HAMs can and do have MUCH longer antennas. I wonder if it's a law for a specific antenna. HAMs would come unglued in DE if it was an antenna length thing.

bluedragon436
07-24-2015, 03:55 PM
Wow that sounds about as dumb as the cutting barbed wire law we have (had?) in Texas. Wait! Are you sure about this? I mean HAMs can and do have MUCH longer antennas. I wonder if it's a law for a specific antenna. HAMs would come unglued in DE if it was an antenna length thing.

Yeah I don't get it... Apparently hams are allowed to have whatever ant. setup works for the rig... but CB's can't??!! I don't know, doesn't make any kind of sense to me.. I just know that he got a few tickets on different occasions for his ant, being too long and a danger to bystanders... which is kind of funny, since he always has the end tied down to the front of his Jeep, not up in the air and whipping around where it'd be dangerous... Kind of confusing to me...

Mudderoy
07-25-2015, 02:51 AM
Yeah I don't get it... Apparently hams are allowed to have whatever ant. setup works for the rig... but CB's can't??!! I don't know, doesn't make any kind of sense to me.. I just know that he got a few tickets on different occasions for his ant, being too long and a danger to bystanders... which is kind of funny, since he always has the end tied down to the front of his Jeep, not up in the air and whipping around where it'd be dangerous... Kind of confusing to me...

I've found there are usually several HAMs in the legislature. :D