Adjusting SWR - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > General Technical Discussions > Electrical, Audio, GPS, & 2-Way Radio > Adjusting SWR

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineRIGID LED Light Blowout Sale - All Sizes, All Series, all Stainless Steel Door Hinge Pins

Reply
Unread 11-12-2013, 12:32 PM   #1
erickpl
Registered User
1997 TJ Wrangler 
 
Join Date: Jan 2005
Location: northern AL
Posts: 4,469
Adjusting SWR

Running a Cobra 29WxNwSt CB and a Firestik antenna.

Antenna got snapped off while wheeling and I replaced the missing 4' antenna with a 3' antenna off my truck. Tried to tune the SWR based on the manual for the CB, but even following those instructions, it didn't want to go below 3.

I'm wondering if something in the mount snapped off or what.

It is mounted to my Jeeperman tire carrier currently.

Any suggestions? Do I need to ground it somehow? Do I need to move it off the tire carrier? The previous 4' antenna got a good SWR (below 1.4), so I'm not sure if the shorter antenna is the problem or what...

__________________
-Paul
Green Jeep Member #155
Low Output 4 Cylinder Jeep Member #35

Keep moving forward. But keep an eye on history, for if you don't, you are doomed to repeat it.
erickpl is offline   Reply With Quote
Unread 11-12-2013, 06:21 PM   #2
CJ7-Tim
Real Jeeps have dents.
 
CJ7-Tim's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2002
Location: out in the garage - Minneapolis, Minnesota
Posts: 21,597
In your situation, excessive SWR indicates damaged components or a faulty replacement antenna.

If the system worked well before the mishap, changing the size of the antenna would have very little, to no effect at all, on the SWR.

CB antenna components are subject to wear and tear from weather, trail damage, and from everyday use. I suggest you buy new CB antenna components including coax cable, and refresh your antenna system.
__________________
.

According to the National Shooting Sports Foundation, AR-15 sporting rifles account for nearly 20% of all U.S. firearms sales.

Progressive Liberalism: Bringing you new Healthcare ideas so wonderful, they have to include mandatory participation ......

Originally Posted by Ronald W. Reagan: Government is not the solution to our problems; Government is the problem.
CJ7-Tim is offline   Reply With Quote
Unread 11-12-2013, 07:51 PM   #3
JPNinPA
Registered User
2005 LJ Wrangler 
 
Join Date: Feb 2011
Location: Dayton, Ohio
Posts: 2,250
Agree

Use an ohm meter to see you still have continuity between the center less radio side and antenna tip. And no continuity between tip and outer shield.
__________________
"Never look down on anyone unless your helping them up"- Jesse Jackson
JPNinPA is offline   Reply With Quote
Unread 11-13-2013, 08:58 AM   #4
erickpl
Registered User
1997 TJ Wrangler 
 
Join Date: Jan 2005
Location: northern AL
Posts: 4,469
I think I found the problem. When I swapped the parts from my truck, I forgot to swap over the plastic isolator washer/spacer that goes around the hole of the mount. Also looks like the stud for part of the mounting assembly snapped when the antenna came off. With that plastic spacer in place, there isn't enough stud to attach the next part of the antenna. Replacing those parts should take care of it.

I did some more digging on SWR on here after posting this and there were some good points that I had to check once I got home. Sure enough, damaged component and missing parts.

Thanks for pointing me in the right direction!
__________________
-Paul
Green Jeep Member #155
Low Output 4 Cylinder Jeep Member #35

Keep moving forward. But keep an eye on history, for if you don't, you are doomed to repeat it.
erickpl is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.