Tuning CB Antenna

[Woodenhead]

I put a CB in my truck with a 48" Wilson antenna mounted on the fender at the second bolt from the cab. When trying to tune the antenna I keep getting an SWR way over 3. I didn't use 18' of cable like the mfg. recommends but I'm pretty sure others have managed to tune theirs with shorter lengths. I'm not much of an electronic nut and probably missed something simple so any suggestions are greatly appreciated.



Thanks in advance

Mike

 

[Whitmore]

Mike, Last I knew the cable must be in 3 foot lengths, and the swr's should be 1. 5 or less to be sufficient.



cheers, Kevin

 

[Bob Wagner]

gonna be doing it too

tuning tips





But I have a firestick

 

[CFAR]

Don't use your radio.







Read the tuning tips link that Bob Wagner supplied.



A high SWR (>3. 0:1) will destroy your cb.

 

[bighammer]

I can't seem to find an SWR meter anywhere locally. Any tips on where to get (or maybe borrow) one cheap?

 

[Woodenhead]

Radio Shack

If you have a radio shack near by you may be able to get one there. That's where I bought mine but alot of Radio shack stores are getting out of CB's.



Bob Wagner, the link to the firestick site gave me plenty of hints and things to consider, thanks.



Mike

 

[WadePatton]

find a ham

Or an amateur radio operator. Most of them have plenty of meters and tools for radio work. If they're like me they were on CB way back when and don't mind helping CB'ers.



But the best advice I can give is to buy the "Now You're Talking" book while you're at radio shack. KNOWLEDGE is POWER and getting a ham license requires learning a little bit about radios, feedline, frequencies, and SWR as well as lots of other little goodies.



Back to the antenna. Tell the ham you'd like him put his "analyzer" on it. Those of us that tinker have a device that makes SWR work extremely easy.



Coax length ain't it.



W1ADE

 

[TowPro]

Re: find a ham

There nice ain't they? I set up my pair of quads on 2m with one, sure made that job easier.

Originally posted by WadePatton

Back to the antenna. Tell the ham you'd like him put his "analyzer" on it. Those of us that tinker have a device that makes SWR work extremely easy.



Coax length ain't it.

 

[bighammer]

That was the part of the whole thing. I went to both Radio Shacks in town and they gave me the WTF look when I asked them for an SWR meter to tune my antenna. I tried another electronics shop, but they aren't into that stuff.

 

[Woodenhead]

The cable I have from Radio shack is RG8/M and is 52 ohms the other cable they had was RG58/? which was also 52 ohm. I know I'm supposed to use cable with 50 ohm impedance but all the cable Radio shack had was 52 ohm. Is this the same stuff or do I need to keep looking for something different.



Also, the cable (shield) is grounded at the radio (right?) do I also need to ground it at the antenna mount or will this create a loop and other possible problems?



Anyone else mount their radio in place of the POS cup holder in the dash?



Mike

 

[tmckenzie]

sounds like your antenna is not grounded good, on some of the trucks i've put antenna's on i had to run a ground wire from the antenna mount to the truck frame.

 

[Woodenhead]

sounds like your antenna is not grounded good, on some of the trucks i've put antenna's on i had to run a ground wire from the antenna mount to the truck frame.

I don't think my antenna is supposed to be grounded. It came with insulating washers for both sides of the bolt kinda like the one called terminals to K4 stud assembly here .



There is a small separate lead on the antenna but the directions say only to ground it if you have problems getting a low enough SWR, I think its supposed to lower the impedance of the antenna.



None the less I did test the mount and it does have a good ground through the fender bolt.



Thanks for all the tips. I bought another piece of cable (18' of mini 8) and will try with it.



Mike

 

[Woodenhead]

It's working !!!!



I put the new 18' cable in last night and just ran the extra back and forth along the cowl. Upon closer inspection the cable from Radio shack (first one) looks pretty cheap didn't even have any identification on the jacket.



SWR is now 1. 3 on CH1 1. 1 on CH20 and 1. 5 on CH40.



Not sure whether it was the length of the cable, grounding both ends, the quality of the cable, eliminating a short...



Thanks for the Tips



Oh yeah, if you need any CB parts (maybe even an SWR meter) go to a good truck stop (flying J etc) the one here in town had tons of stuff.



Keep yer stick on the ice

Mike

 

[fj40charles]

On a related note. . who makes a good SWR meter? I checked ebay and I see some real cheap ons and some expensive ones.



Does it make any difference to buy the expensive model?



Thanks in advance,

Charles

 

[WadePatton]

Originally posted by Woodenhead

The cable I have from Radio shack is RG8/M and is 52 ohms the other cable they had was RG58/? which was also 52 ohm. I know I'm supposed to use cable with 50 ohm impedance but all the cable Radio shack had was 52 ohm. Is this the same stuff or do I need to keep looking for something different.

Also, the cable (shield) is grounded at the radio (right?) do I also need to ground it at the antenna mount or will this create a loop and other possible problems?

Mike

There is no practical difference in 50 and 52 ohm coax. 75 ohm works fine. Be a ham, learn how to use 300 and 450 ohm line.



Larger lines have less loss and better shielding.



The coaxial cable, by design, grounds to xmitter chassis and to antenna mount-thus vehicle in this application. The antenna is what is insulated. The center conductor of the feedline carries the signal to the antenna.



And CB shop coax is usually better than Radio Crap stuff.



Belden is the big name in coax. Go to some HAM RADIO equipment websites. The sell all the stuff CB'ers need and usually better than RS and CHEAPER than CB stores.



Try Ham Radio Outlet or Amateur Electronic Supply.



Don't worry about all the stuff you don't know about, just look at coax and test equipment. Especially don't look at the 1500-watt amps that are perfectly legal for us hams to use on most bands.

 

[WadePatton]

Originally posted by fj40charles

On a related note. . who makes a good SWR meter? I checked ebay and I see some real cheap ons and some expensive ones.

Charles

If you are just going to CB, use the cheapest you can find. The fancy ones are for hams who need SWR readings on multiple bands. And they have all sorts of other silly functions.

 

[_Hyde]

Hey FJ,



I assume you are still in the DFW area. I have an SWR meter that I got from my Dad when he was a ham. Not sure how good it is but it sounds like anything will work for us lowly CBers. Maybe I could be a ham when I grow up. Anyway, if you come out to one of the Big D Dodge Diesel Club meetings in Carrollton sometime I can pack it along if you would like to use it. Let me know.



Darren

 

[WadePatton]

Stirring the pot a bit.

Originally posted by Hyde

Hey FJ,

I assume you are still in the DFW area. I have an SWR meter that I got from my Dad when he was a ham. Not sure how good it is but it sounds like anything will work for us lowly CBers. Maybe I could be a ham when I grow up.

Darren

Sorry if I came off too harsh there. I'm just flat out amazed that people will spend the money and time to have a good CB set up--which is EXTREMELY limited, and then express no interest at all in a radio communications hobby that has so MUCH MORE to offer. You (Darren) have the advantage of knowing someone who was(?) a ham so you might know something about it. Most folks are like I was up until 1995 and know nothing about ham.



It's easy, it's fun, and it can be cheap--I'm quite thankful for my time on CB--because it led me to amateur radio. And every now and then (road situations) I wish I had a CB. But then I remember the hash and trash and losing communications at 20 or 30 miles and all the other limitations...



ANYBODY! PM me if you want more infoOo.

 

[fj40charles]

Darren,



Thanks for the offer. Since it is so cheap, I think I'll buy one off of ebay. I figure I'll get my money's worth since I have two vehicles with CB's.



Wade,



Thanks for the info... . No, you did not come off too harsh. I don't know much about CB's, but I do know I need to replace my antennae and want to tune it myself.



Charles

 

[_Hyde]

Didn't THINK you were being too harsh myself but as you know the big limitation of written communication is that the possibility of being perceived the wrong way is quite high. I agree that ham has much more to offer. My Dad used 2 meter quite a bit prior to getting out of it. My uncle was transfered to Iowa back in the late 70s or early 80s and they got into it to save on LD phone bills. I think it was just a good excuse to take up another hobby. They both stuck with the 2m thing after uncle moved back for a while. Not sure if here's still in it or not. I've thought about 2m from time to time. I mainly use CB as early warning and intel when out on the road but the garbage does wear on you a bit. When caravaning with friends I'll use it and just turn the squelch way up but we also have FRS for that use so the CB is not quite as critical. FJ, I'm assuming you have a CB your FJ also and use out on the trail. Ever go out to Barnwell?







Darren