High SWR on All New CB Setup

[dlhanse]

Hi. New to the hobby. Installed new CB system on Ford Ranger Truck. Getting very high SWR reading above 3.0.

All equipment is brand new. Antenna tests good. Have tried 2 different radios and 3 different antennas, and 3 sperate cables.
Coax cable tests good, no short, no breaks.
Mounting bracket is grounded properly, no shorting across nut. Good isolation between antenna and bottom nut. Grounded to chassis with 8" long ground cable, and also mounted directly to metal. Continuity confirmed with meter from mounting bracket and negative battery terminal.
Antenna (2' fiberglass) mounted near the rear of truck on the top of the bed wall. Not close to cab in open air. Sticks above cab 10".
SWR tested in open field.

What else can I do?

Thanks

 

[wjm1129]

That antenna is too short to tune properly. You need at least a 4 foot antenna for a good swr.

 

[prcguy]

An antenna mount needs to ground right at the vehicle outer sheet metal. Is that possible or is the mount insulated and that's why you have an 8ft ground wire? Ground continuity with a meter means nothing to an antenna, it wants to see and feel lots of flat sheet metal right below it.

 

[nokones]

Hi. New to the hobby. Installed new CB system on Ford Ranger Truck. Getting very high SWR reading above 3.0.

All equipment is brand new. Antenna tests good. Have tried 2 different radios and 3 different antennas, and 3 sperate cables.
Coax cable tests good, no short, no breaks.
Mounting bracket is grounded properly, no shorting across nut. Good isolation between antenna and bottom nut. Grounded to chassis with 8" long ground cable, and also mounted directly to metal. Continuity confirmed with meter from mounting bracket and negative battery terminal.
Antenna (2' fiberglass) mounted near the rear of truck on the top of the bed wall. Not close to cab in open air. Sticks above cab 10".
SWR tested in open field.

What else can I do?

Thanks

If you are using a Firestik, is it a Firestik II with an adjustable tip? A 4 Ft Antenna would work a lot better on the VSWRs but a 5 Ft. would be better. What VSWR readings are you getting on Ch. 1, Ch. 20, and Ch. 40?

 

[WSAC829]

That antenna is too short to tune properly. You need at least a 4 foot antenna for a good swr.

I beg to differ. I use a 3 foot Diesel whip on my F150 with a hood/fender mount. It has a super low SWR across all 40.

 

[slowmover]

Tuning Guide

Welcome! Some images wouldn’t hurt. Most problems are mount type & location. As above, it’s the sheetmetal underneath that is one half of the antenna.

I wouldn’t get too hung up on total length at beginning, but . . . .

Low SWR is “nice” (@ 1.5:1), but total antenna length is an equivalent to performance. One might hear “okay”, but to expect to be heard, a 5’ is where reasonable performance begins.

A quarter-wave antenna is 9’. Staying above half that length is best.

7’ is where best design/manufacture creates an antenna better suited to the high wind loads of mobile operation. Whether a base load SIRIO 5000 or a mid-coil PREDATOR 10K-1-27 is chosen is almost a preference, now is performance optimized without the wind whip of a 108”.

Static mobile to mobile is a nice stand-in as a test, but it’s clarity at greatest distance while underway where one learns that (first), there’s no substitute for height, and (second) that antenna particulars matter.

A SIGNAL ENGINEERING GR 45 is a partial exemption in length given its top hat design. Not as tall as the two above, but more likely to catch against obstacles if not careful. With a fairly ordinary radio it gets outstanding reports.

An all-around best start is a 6’ Skipshooter. Not as flexible as the 7’, but with very good top load performance that’ll put any 3-4’ antenna to shame. “Clear” cover stands out least, and it’s a low price

Not for nothing I learned to buy this brand in pairs (big truck).

OP, FWIW, I ran a mag mount on the pickup roof for many years. Location trumps almost all else, just ahead of total height.

If you expect to hear and be heard about a mile or so, it’s not hard to get going. If you want real performance, it’ll take more planning and work. A mile isn’t enough in high speed rural traffic.

— Stick around long enough to work through a good solution for what you have right now. Report back to keep working details.

.

 

[robertwbob]

bad vswr meter or bad jumper.unless your using built in vswr meter. that many changes should produced diffrent results. we are not there so walk us through whole process . i think we are missing a link or 2 in your setup. can you hear other radios?
oh if you can remove coax from antenna with ease check continuitu. might be 1 thin wire from braid touching center wire post in pl259

 

[dlhanse]

Tuning Guide

Welcome! Some images wouldn’t hurt. Most problems are mount type & location. As above, it’s the sheetmetal underneath that is one half of the antenna.

I wouldn’t get too hung up on total length at beginning, but . . . .

Low SWR is “nice” (@ 1.5:1), but total antenna length is an equivalent to performance. One might hear “okay”, but to expect to be heard, a 5’ is where reasonable performance begins.

A quarter-wave antenna is 9’. Staying above half that length is best.

7’ is where best design/manufacture creates an antenna better suited to the high wind loads of mobile operation. Whether a base load SIRIO 5000 or a mid-coil PREDATOR 10K-1-27 is chosen is almost a preference, now is performance optimized without the wind whip of a 108”.

Static mobile to mobile is a nice stand-in as a test, but it’s clarity at greatest distance while underway where one learns that (first), there’s no substitute for height, and (second) that antenna particulars matter.

A SIGNAL ENGINEERING GR 45 is a partial exemption in length given its top hat design. Not as tall as the two above, but more likely to catch against obstacles if not careful. With a fairly ordinary radio it gets outstanding reports.

An all-around best start is a 6’ Skipshooter. Not as flexible as the 7’, but with very good top load performance that’ll put any 3-4’ antenna to shame. “Clear” cover stands out least, and it’s a low price

Not for nothing I learned to buy this brand in pairs (big truck).

OP, FWIW, I ran a mag mount on the pickup roof for many years. Location trumps almost all else, just ahead of total height.

If you expect to hear and be heard about a mile or so, it’s not hard to get going. If you want real performance, it’ll take more planning and work. A mile isn’t enough in high speed rural traffic.

— Stick around long enough to work through a good solution for what you have right now. Report back to keep working details.

.

I made a short video