Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > General Jeep Discussions > Communications and Electronics > Wacky SWR readings

Join Wrangler Forum Today

Thread: Wacky SWR readings Reply to Thread
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options
Miscellaneous Options

Topic Review (Newest First)
04-02-2013 08:39 PM
Jerry Bransford Perhaps the nylon insulating shoulder washer isn't properly seated & allowing the antenna to touch the steel mount which shorts it to ground. Or the mount's lower part that is supposed to touch bare metal on the under side of the mount isn't tight or not enough powder coating was removed to make the RF ground's electrical connection reliable.
04-02-2013 07:51 PM
truthiness SWR is still stuck at 3+ no matter what I do even after doublechecking my ground contact. I'll have to check my connections this weekend when it warms up.
04-02-2013 07:43 PM
Jerry Bransford Anything touching the antenna can change its SWR. So while I've never measured the SWR with a dry vs. a wet antenna, knowing the many factors that can affect an antenna's resonance point there is no doubt that rain could affect it.
04-01-2013 01:12 AM
truthiness It was tuned to 'in use' conditions with the vinyl cap down to 1.2.

With a light drizzle SWR went to 1.5 on channel 40, when I took cap off to tweak (from my previous trial and error I knew it was probably less than a half turn on my Firestik) I came back into the cab and everything was above 3 and tuning did not respond.

Any ideas? Was it because it was wet out?

I guess what I'm trying to say is that I couldn't even get it back to previous 1.2/1.5, it just blew everything to 3 with just me removing the antenna cap and fiddling with the tune. I thought maybe something got wet somewhere because it was sprinkling out. Probably not a smart move, I know.
04-01-2013 01:06 AM
Jerry Bransford Reinstalling the vinyl tip-cap adds electrical capacitance which will dramatically change the antenna's SWR. You have to tune the antenna to one side of its point of minimum SWR so reinstalling the vinyl tip cap will bring it back down to where you want it. It's a trial and error thing but it's not so hard. You'll quickly find which side of minimum SWR the antenna needs to be tuned to so reinstalling the vinyl tip cap lowers the SWR back down to its minimum (good) point.
03-31-2013 11:35 PM
Wacky SWR readings

I'm running a Midland 75-822 handheld with the Cooltech Gatemount setup which includes 18' coax with molded Firering and 4' tunable Firestik firefly antenna. Initial install gave me SWR hitting about 3; wound up sanding paint off of my ground point under the rear tie down loop and dialed in my SWR to a respectable 1.2 on channels 1 & 40. At channel 19, needle didn't move, a solid 1, I was psyched.

Hopped in my car tonight and noticed my SWR was 1.2 on 1, but had creeped up to 1.5 on 40 and I wanted to tweak it. There was a slight drizzle and after I removed the cap on my Firestik and adjusted my tune, I went back into the Jeep and my SWR was 3+ and I couldn't get it to move no matter what I did with the antenna or ground.

Any suggestions?

Posting Rules
You may post new threads
You may 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

All times are GMT -5. The time now is 05:01 AM.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC. is not in any way associated with the Chrysler Motors LLC