Need help tuning cb antenna

[DiscoPete]

So I installed everyonf but noticed my swr is way to high , did lots of reading and know I need to cut the antenna but I would rather get help from someone that done this before I mess up and break somthing , any takers Iam located in Milton but willing to drive for some help

[Bow_Tied]

We should really have a CB tuning meet - I have a SWR and don't know how to use it!

[Rev]

Are you certain you don't have a tuneable tip?

[DiscoPete]

Rev explain , I have a uniben pc87xl radio and a basic antenna and mount from 5th wheel
I have a swr reader on my cb so I just need help setting it up

[Xtrapol8]

Rev explain , I have a uniben pc87xl radio and a basic antenna and mount from 5th wheel
I have a swr reader on my cb so I just need help setting it up

Antennas are tuned by adjusting their length. All antennas have roughly 9 feet (108") of wire (I could be off a bit on the exact length.) The really long whip antennas have that wire in one straight line whereas the other antennas have much of the wire wrapped up somewhere. Many antennas have a tip, at the very top - often covered by a rubber cap, that is a set-screw for you to adjust. When I asked, the guy at the CB shop told me that because the screw is right at the end, even half a turn can produce significant changes.

I hope I remembered and reported all of this correctly reported and that it helps.

Good luck.

[DiscoPete]

Cool thanks but I checked my antenna and it dosent have a screw under the rubber cap :s

[petespath]

I have never been but people do say their good, doesn't hurt to call them.
http://www.radioworld.ca/" onclick="window.open(this.href);return false;

[HolidayNation]

Rev explain , I have a uniben pc87xl radio and a basic antenna and mount from 5th wheel
I have a swr reader on my cb so I just need help setting it up

Antennas are tuned by adjusting their length. All antennas have roughly 9 feet (108") of wire (I could be off a bit on the exact length.) The really long whip antennas have that wire in one straight line whereas the other antennas have much of the wire wrapped up somewhere. Many antennas have a tip, at the very top - often covered by a rubber cap, that is a set-screw for you to adjust. When I asked, the guy at the CB shop told me that because the screw is right at the end, even half a turn can produce significant changes.

I hope I remembered and reported all of this correctly reported and that it helps.


It is actually based on the 1/4 wave, =102". Pezzy has a full 1/4 wave (102") whip.

here is a good primer for tuning an antenna. It is not really that hard, but if you are trimming, go about an 1/8 of an inch or so at a time. It takes a bit of time, but not that hard.
http://www.rightchannelradios.com/pages ... c0-61.html

[Scotto]

Jesus, Eric, you're making everyone do maths and number stuff. 1/4 x 102" divide by 10 and adjust by 2 and 1/3 thou and all is good... Oh, my head hurts. Math is hard.

And by the way, just so Pezzy doesn't get all the credit for having the only mantennae around, the whip on my truck is a full 1/4 wave, or 102".

I say check your coax and things might get better.

[HolidayNation]

Jesus, Eric, you're making everyone do maths and number stuff. 1/4 x 102" divide by 10 and adjust by 2 and 1/3 thou and all is good... Oh, my head hurts. Math is hard.

And by the way, just so Pezzy doesn't get all the credit for having the only mantennae around, the whip on my truck is a full 1/4 wave, or 102".

I say check your coax and things might get better.

You're a 1/4 wave....

[Bow_Tied]

bwahahahahahahah!

[Rev]

Rev explain , I have a uniben pc87xl radio and a basic antenna and mount from 5th wheel
I have a swr reader on my cb so I just need help setting it up

Ok, how about at the base? Is there a little set screw? That is how mine works.

Can you take a pic?

[DiscoPete]

another question, my car has a pretty bad ground it self, will this effect my radio performance/ antenna performance , would i need to ground my cb right to my battery vs a ground on my car, also ive been also reading about grounding your antenna as well, any benefits to this?

dam iam a noob to this poop, i under stand mechanics alot better then i do with electricity and frequencies

[DiscoPete]

so i started doing swr tests and iam running 5 times as high, and i noticed that even with out an antenna hooked up to my coax cable iam still over any ideas?

[Bow_Tied]

Is the antenna properly grounded to a known, good ground? Same is needed for the CB unit.

[DiscoPete]

No my antenna is not grounded but it's attached right to my side panel which is metal , my cb is properly grounded , would it be an issue if my truck has a bad overall ground ? As my lighs flicker a bit when I drive ?

[Bow_Tied]

Maybe? It wouldn't help.

Try these tests:
http://www.firestik.com/Tech_Docs/swr-trblshoot.htm" onclick="window.open(this.href);return false;

[DiscoPete]

Okay guys foud my problem and it's kinda
a silly one , put the plastic washer on the wrong side of the mount haha , works swell now

[Bow_Tied]

It sounded like a ground issue; glad you got it figured out.