Firestik adjustment - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > General Jeep Discussions > Communications and Electronics

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 09-21-2016, 12:11 PM
Thread Starter
  #1
Jeeper
 
stew930's Avatar
 
Join Date: Jul 2010
Posts: 79
Firestik adjustment

My CB seems to function fine with the screw all the way down on the antenna. Is there any benefit to raising the screw to add some range?

stew930 is offline   Quote
Old 09-21-2016, 02:40 PM   #2
Supporting Member

5-Year WF Supporting Member
 
TerryC6's Avatar
 
Join Date: Jan 2014
Location: Hesperia, CA
Posts: 6,880
Quote:
Originally Posted by stew930 View Post
My CB seems to function fine with the screw all the way down on the antenna. Is there any benefit to raising the screw to add some range?
What is your SWR? The screw is to adjust that. It in and of itself will not add any range. But if adjusting it up lowers your SWR you will get a cleaner signal and added range.

__________________
Terry

35" Baja MTZ P3's - Level 8 Tracker Pro 5 Wheels - Dynatrac ProGrip Brakes - MetalCloak 2.5" GC Suspension, 6Pak Edition - Griffin Attenuator - Artec Front Axle Armor - Nitro Axle Sleeves - JCR Vanguard Bumpers - Poison Spyder Brawler Rockers & Bombshell Diff Covers - RockHard 4x4 Skid's & Sport Cage - Genesis Dual Battery Kit with G Screen - SPOD - Zeon 10-S - VisionX headlights - Traildash 2 - Morris Mule Trailer
TerryC6 is offline   Quote
Old 09-21-2016, 03:51 PM   #3
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 48,379
That screw is designed for one purpose, to fine-tune the antenna's length so it can put out the most possible power. Too short or too long and the antenna won't transmit with as much power as the CB is capable of providing... so unscrewing the tip to make it longer will typically not help at all and doing so would likely make it worse.

What you need to do is to set the antenna's length so it is the right length to transmit with the most power. You do that using an SWR meter which you use to know when the antenna is at its correct length from adjusting its length shorter/longer.

SWR meters are usually under $20 on places like Amazon.com and come with complete instructions. You don't need to be an electronic wizard to use the SWR meter, you just need to follow the instructions that come with it.

Here's a good inexpensive SWR meter at Amazon.com which also includes the short jumper cable needed while the SWR meter is being used... https://www.amazon.com/METER-Radio-A...s=cb+swr+meter
__________________
When you have a choice, buy American.
Jerry Bransford is offline   Quote
Sponsored Links
Advertisement
 
Old 09-21-2016, 09:17 PM   #4
Jeeper
 
ULEWZ's Avatar
 
Join Date: May 2016
Location: Northridge, Ca
Posts: 408
Make sure you do the swr measurement with the red plastic cover installed at the top of the antenna (remove to adjust of course). We found it made a huge difference in swr readings using an antenna analyzer on my 2 foot firestik..
__________________
I call her Mall-ie
ULEWZ is offline   Quote
Old 09-22-2016, 09:54 AM   #5
Jeeper
 
sparky's Avatar
 
Join Date: Oct 2009
Location: Phila
Posts: 3,462
Quote:
Originally Posted by ULEWZ View Post
Make sure you do the swr measurement with the red plastic cover installed at the top of the antenna (remove to adjust of course). We found it made a huge difference in swr readings using an antenna analyzer on my 2 foot firestik..
and the doors closed. Don't stand beside the Jeep either. Make your measurements in the same style you would be using the radio.
__________________
Just because you're offended, doesn't mean you're right.
sparky is offline   Quote
Old 09-22-2016, 01:18 PM   #6
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 48,379
Quote:
Originally Posted by sparky View Post
and the doors closed. Don't stand beside the Jeep either. Make your measurements in the same style you would be using the radio.
In theory that affects it but it doesn't in practice in my experience and years of tuning CB antennas. Perhaps it affects VHF/UHF more easily, I dunno since I never experiment on that while tuning them, but simply standing next to the Jeep for the SWR check never affected a CB antenna's tune enough to see it in my personal experience.

I've tested and demonstrated to friends several times that standing near enough to the antenna to see the meter while in the tuning process doesn't really affect it. Raising my hand/arm so it is close to the antenna like I was going to adjust its tuning tip definitely and readily/dramatically affects the SWR. But if I just stand adjacent to the antenna with my hands at my sides while reading the SWR meter, it gives the same indicated SWR as it does when I back completely away from the antenna. The meter doesn't move as I back completely away.

I was curious about that years ago so I started watching my body's effect on the SWR while tuning CB antennas while standing close enough to view the SWR meter on its 3' jumper cable. After never being able to see any significant effect, I stopped worrying about it.
__________________
When you have a choice, buy American.
Jerry Bransford is offline   Quote
Old 09-26-2016, 10:41 AM
Thread Starter
  #7
Jeeper
 
stew930's Avatar
 
Join Date: Jul 2010
Posts: 79
I left the screw all the way down and calibrated it which worked well on the Deadwood Jeep Jamboree I went on this past weekend.

Thanks for the advice.
stew930 is offline   Quote
Old 09-26-2016, 10:43 AM   #8
Jeeper
 
ConnecticutJunkMan's Avatar
 
Join Date: Jul 2016
Posts: 251
On my little 2' firestick the cap moves the dip down around 400kc's. Maybe wouldn't be much of an issue on the longer ones but this little thing is so narrowbanded that little amount matters if you want it below 2.0 across the CB band. I had to keep tuning past where I wanted then put the cap on to see where it landed.
The longer ones I have played with where no where near this finicky but I guess thats what happens when you pack 11m 1/4wave in to 24 inches lol
I ended up getting ch18 at down to 1.17 and the 1 & 40 around 1.9ish. 1/4turn made a big diff.
ConnecticutJunkMan is offline   Quote
Old 09-26-2016, 10:57 AM   #9
Jeeper
 
BreakIt's Avatar
 
Join Date: Feb 2016
Location: Phoenix
Posts: 527
This is why I love this forum. You come in here to ask a question and the gurus come out in force to not only answer, but guide you through every important step.
You guys are super duper awesome. Thank you for all of your help!
Jeep On!

BreakIt is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off






All times are GMT -5. The time now is 02:24 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

Jeepģ, Wrangler, Liberty, Wagoneer, Cherokee, Gladiator, Mopar and Grand Cherokee are copyrighted and trademarked to FCA US LLC.
Wranglerforum.com is not in any way associated with FCA US LLC.