Jeep Wrangler Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
2,262 Posts
Discussion Starter #1
I recently installed a Uniden 520, 3 foot Firestik tunable tip with screw ant. with a Teraflex passenger side tail light mount, and 18' cable. I have low SWR's (under 1.5 all 40) connections are tight, and ant. mount was ground to metal as was the tub. I do have a sharp bend in the cable at the cb for the cable to go above the sport cage to the rear of the Jeep.

My question is would this sharp bend (out about 4 inches and then doubled back, but not kinked) effect range, and if so if I take it out with more slack will it effect my current SWR readings?

I am only getting about 1.5-2 miles in range with another cb'er, although his antanae (sp) is IIRC 5'. He can continue to hear me after I drop him completely.

I have not really heard much traffic on the band and attempts for a "radio check" on I85 proved unsuccessful (mainly due to lack of radio traffic, I think). When I do hear chatter it seems distant and kinda garbled. It sure ain't like it was back in the early 90's....
any help would be appreciated...
Thanks Jeeper's...
 

·
Registered
Joined
·
64 Posts
I do have a sharp bend in the cable at the cb for the cable to go above the sport cage to the rear of the Jeep.

My question is would this sharp bend (out about 4 inches and then doubled back, but not kinked) effect range, and if so if I take it out with more slack will it effect my current SWR readings?...
It is not clear to me how sharp a bend you have. It is not affecting your operation now but depending on the type of construction and internal materials, the center conductor can pull thru the insulation and short to the shield over a period of time. The tension on the center conductor can cause "cold flow" of some insulators. Best to remove the sharp bend now and relieve any tension. A bend radius of 1.5 inches or more should not be a worry. It will not affect your VSWR if you do straighten it out now.

A good VSWR number, such as yours, is not an indication of how well the antenna is radiating or receiving. Lots of variables in the mounting location. You need more testing with other CB users before you can make a fair estimation of how well your system is working. Your range is heavily dependent on the terrain between you and the other party, so you may not have any issues at all.

The noise level of your vehicle and subsequent squelch setting will have a large effect on your receiving range.

Phil
 

·
Registered
Joined
·
2,262 Posts
Discussion Starter #3
cool thanks, after I posted I pulled in some slack and the bend is now not near as "bent". I will probably reroute the cable all together next week when I am off again.
 

·
Registered
Joined
·
3,513 Posts
An antenna on the rear corner can be somewhat directional. A number of factors are involved. All of the ground plane / counterpoise (body and frame) is front and slightly left, which tends to direct the radiation in that direction. However the roll cage acts as a screen siince the antenna is not above it. Hard to say which effect wins. With your buddy two miles away try contacting him with the Jeep facing various direction. See which is better.

Anothe factor is terrain. Are you down in a valley, surrounded by trees or buildings?
 

·
Knows a couple things...
Joined
·
49,001 Posts
With those SWR readings, the antenna would not be causing a receive problem. And I assumed when you checked your SWR that the meter indicated your CB is putting out the normal amount of power, close to 4 watts.

Make sure your squelch control is not turned up too high, that would cut out weaker CB signals.

And realize that the CB band is not all that busy now, I might turn mine on and scan through the channels on a long trip and I often don't hear any CB'rs on at all even here in SOCAL.
 

·
Registered
Joined
·
2,323 Posts
... I do have a sharp bend in the cable at the cb for the cable to go above the sport cage to the rear of the Jeep...
To avoid the sharp bend issue, I would suggest you place a 90° connector in between the CB and the end of the antenna cable.

Truckspec TSM-358 90 Degree L Connector - Pl-259 To So-239 by Truckspec | Toolfetch

These are available at any major truck stop.

In my particular case, to avoid having that problem, I mounted my CB to my CB bracket, using 1 central bolt. That way, I could swivel my CB to any direction I wanted.

**Edit**
Sorry about the picture.
I can't seem to get it to orient the correct way.
 

·
Registered
Joined
·
2,262 Posts
Discussion Starter #7
An antenna on the rear corner can be somewhat directional. A number of factors are involved. All of the ground plane / counterpoise (body and frame) is front and slightly left, which tends to direct the radiation in that direction. However the roll cage acts as a screen siince the antenna is not above it. Hard to say which effect wins. With your buddy two miles away try contacting him with the Jeep facing various direction. See which is better.

Anothe factor is terrain. Are you down in a valley, surrounded by trees or buildings?

It's actually above the top of the Jeep by about 10 inches, it was an overcast day it had just stormed pretty bad, but it was barely raining when I left his house. We were both in the flat, but I had trees on either side of the 4 lane highway with a grassy median. I was driving away from him and his Jeep was parked to where his ant was facing opposite the direction I was going.
 

·
Registered
Joined
·
2,262 Posts
Discussion Starter #8
thanks everyone. I will keep tinkering with it and let you know if it gets better. I am thinking its right, just the weather was the factor the other day.

My wife thought I was nuts anyways for putting one in. She didn't realize our wheeling buddies had them in their Jeeps... ha
 
1 - 8 of 8 Posts
Top