CB Radio tuning with Firestik 4' antenna.

[jafo]

Decided to finally replace my 10' whip with a firestik 4' tuneable antenna. Been kind of tough working through tuning this. I have a Uniden cb right now and am still a novice/beginner. Thing is, when tuning, got it in an open area maybe 120 acres round. But next to a road moderate traffic. I backed the jeep away from the road and hooked up my swr meter. Was getting hi readings but they stayed close to equal between channels 1 and 40. I had the meter setting in the passenger seat, and me in the drivers when conducting the readings. I was getting 2.7 to 3.0 swr readings both channels. It would vary. I was trying different mounting positions and mounting configurations. One with and one without the heavy spring. Didn't seem to matter. Then the odd thing happened. I happened to lift this metter up about a foot and it instantly dropped the swr reading to almost a 2. So I decided to stand outside the passenger side door and run the test. The swr meter I have has a small antenna and it seemed to be having issues making contact or something and after a couple adjustments and mount figuration, it's giving me an swr reading of 1.2 on both channels. Question is, I don't know if what I was doing was wrong or how I finished was wrong. Any ideas?

 

[jp360cj]

What kind of mount are you using? Where's the antenna? Is your test repeatable?

FWIW, I run a 4' Firestik Firefly on my CJ7 mounted on the back of the tub with an L bracket and a Uniden Pro 520XL. It works very well for a short antenna. I've talked 8.8 (gps verified) down the beach with no issues, granted the other guy had a big whip antenna).

 

[Lumpy Grits]

1.2 is fine. Anything under 1.5 you're GTG.
Hope you adjusted the ant. with the engine running. It will make a difference.
LG

 

[jafo]

Thanks for the input guys. I am using the Firestik "L" bracket mount. I have mine on the rear passenger corner of the tub. As low as you can go. Being I park the Jeep in my garage and it's my daily driver, wanted it to fit without rubbing or minimal rubbing.the trst was repeatable. BUT, therein lies the issue. By moving the swr meter from the most interior part of the jeep to by the door edge to get the lower reading. It was consistent either way. Thats why it's confusing me. I need to run a new coax really to be sure I think. Looking at a Firering coax.

LG, I adjusted the antenna up a 1/4 inch and they came out identical. Yes the engine was running. I was freezing my butt off. So engine running a good or bad thing while adjusting the antenna?

 

[jp360cj]

So adjusting the antenna 1/4" didn't change the SWR readings at all? IIRC, that a pretty big change on the antenna and I would expect something to change. Before buying another coax, I would try to find another SWR meter to borrow and see if you get the same results.

 

[Lumpy Grits]

Be sure the ANT connections are good and you have a confirmed good GND.
X2 on trying a second meter.

LG

 

[jafo]

No, it did change the swr reading. It brought channel 40 down to around or right at a 1in line with channel 1. This coax is pretty old. It had spots where the insulation was broke or split. Wrapped it with 3m electrical tape. I am the only person I know that has a swr meter. I would have to buy another one. Not that many cb'ers around here that I know. The ground is one thing I made sure had good connections. I ran the ground directly to the frame with a 14 guage wire and weatherproof amp eyes. I also covered them in dielectric grease as well.

 

[Lumpy Grits]

What ratio was chl 20?
What chl do you use the most?
You may well want to get new cable, and add a noise filter on the radio's power supply.
LG

 

[jafo]

LG, I miss Radio Shack. I gotta hit the truck stop for cb radio stuff. They got a good selection but can be pricy. Channel 40 was a 1.3 ratio I think. I'm so new to this, I don't have a favorite channel. Whith the whip antenna, I used to leave it on channel 6. Just had the most chatter. But I've seriously considered getting a Hamm license, but need to get familiar with radios in general first. That's why I decided to start with a CB and go up from there.

 

[jp360cj]

I don't really have a favorite channel either. I usually run 19 and pick up a lot of trucker chatter (mostly from local log trucks). On our Jeep rides, we usually run 22 or 23 simply because the first time out we had to decide on a channel. One guy turned his CB on and it was on 22, so it stuck.

 

[Lumpy Grits]

Each off road club will have it's favorite CB channel.
Some run FRS and/or 'HAM'.
K6MTY
LG

 

[jafo]

I take it you're a licensed hamm operator LG? Kind of wish my wife uncle was still with us. WWII pilot and was big into Hamm radio and cb's I guess also. But I remember seeing his set on his desk and a big antenna out back. I am starting to get really interested in that stuff but din't know where to start. Not many radio shops around.

 

[jafo]

I still got that I think it's a 2meter radio, a Yaseu or something like that. I and the guy I bought it from didn't realise what it was. We thought it was a regular cb. LOL! I talked on here some about it a while back and found out I needed a hamm license to use it. I still have the website someone linked me to on getting a license. Just haven't took the time.

 

[jafo]

Jp360, I heard something about channel 19 somewhere. So that's mainly what the truckers use then?

 

[Lumpy Grits]

Did the 'HAM' thing for decades-Not so much now.
You need a lic for HAM, 2 & 10 meter.
No lic needed for CB or FRS.
CB-CHL 19 for truckers and CHL 9 for emergency ONLY.
See if there's any radio clubs in your area and go from there.
LG

 

[jafo]

Ok. Put on a new coex cable yesterday. This one has the connectors on both ends. My original had an amp eye on the antenna end and connector on the other. Swr got worse. Went to mid 3's on both channels. I wound up taking the adjustable tip out and got a 2.3 on channel one and 2.7 or 8 on channel 40. Going to try a different cb today.

 

[jafo]

Ok, went out this morning. Two cb's, two antenna's. One cb is a Cobra classic, the other is a Uniden bearcat. One antenna is the 4' firestik and the other is a short adjustable. I decided to have the Cobra mated to the Firestik and wound up using the old coax cable with the amp eye on the antenna side. It gabe me pretty consistent readings around 1.5 on the swr meter. The Uniden cb I mated to the magnetic shorter antenna and wound up the best I could get was 2.3 on the swr meter. The new coax cable with weather proof connections between the Cobra and Firestik gave me 2.4 on channel one and 2.8 on channel 40 on the swr meter. I'm going to go out and install the Uniden in my truck then test link the Uniden and Cobra radios. I did notice one odd thing. When trying to check readings with the old coax cable, when I was adjusting the meter to set location, my hand movement seemed to effect the meter. The adjustment dial is on the same side as the coax for the antenna. So I'm just going to go with the setup as is for now.

 

[jafo]

Ok. I got both cb's on. Both on same channel. All I get from either radio is a buzz when the mic is pressed. I can't hear any audible voice come through. What is going on? Both radios are in same garage maybe 10 ft between them. To close? What am I missing?

 

[Lumpy Grits]

Anything above 1.5 will harm the radio with feedback.
You want the PL-259 connector on one end only, and ring connectors on the other.
CB, coax is cut to specific lengths, and should not be cut and more.
Your radios are way to close-Get about 50' spacing.
You should not try to tune a antenna in the garage. To much EFI from lights and such.
My Mom was a WW2 W.A.S.P, and meet my Dad(HAM)when she applied to Western Airlines after the war.
LG

 

[jafo]

Ok. The only thing I have done with the older coax is replaced the ampeye. The new one had the PL-259 connectors on both ends. Not using that one currently. So as of now, I am running the old coax with one PL connector on one end and ampeyed at the antenna. The other radio is using one of those short antennas with a magnet pedistal. It's using the coax that is made into the antenna. I don't know what else to do to the radio with the shorter antenna to get the swr down any further. I have the radio in the jeep down to around a 1.5 - 1.2. I have another antenna I can try. But I woupd have to splice in another coax to it. It's about a 2 or 3 ft. antenna.