Antenna and spare tire
JK Newbie
Joined: Jul 2012
Posts: 74
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From: Detroit area
JK Enthusiast
Joined: Apr 2012
Posts: 316
Likes: 0
From: Little rock, Arkansas
Originally Posted by Nico4x4
Would it affect the quality of my signal if my CB antenna would touch the spare tire when mounted?
JK Freak
Joined: Apr 2011
Posts: 719
Likes: 0
From: Lakeland, Florida
Can't touch this!
In spite of what I read here, I have my antenna mounted on the tail gate between the gate and the spare. It has performed great (SWR 1.0 - 1.4 and 5+ mile transmission) for over a year so don't tell me I need to move it. The reason (in my not so humble opinion) the gate mount works on a Jeep (and maybe not so much on a Tahoe) is because the gate is relatively short and the spare rim is not so big... so the majority of the antenna is not sandwiched between metal but extends above.
My antenna is a FireStik Firefly FL-4. It is NOT an ungrounded type antenna so it was very important the antenna bracket is grounded to the Jeep frame since the frame acts as the "couterpoise" which allows the antenna to propogate radio waves. Only ungrounded antennas work without grounding to the frame. With an ungrounded antenna, the coax shield acts as the couterpoise. Not as efficient as using the vehicle body/frame as the ground plane but better than nothing if your vehicle has a fiberglass body. (plastic Jeep? fiberglass fender mount?) Also, my antenna is insulated (not bare metal) although where the antenna screws into the bracket is exposed and must not be gounded. My antenna is very flexible and bouces against the spare all the time. Touching the spare is never a problem.
So, ground the antenna bracket to your frame and make sure the center connection remains insulated from the body.
Caveat emptor: This applies to CB not necessarily HAM, satellite, cell boost.
Handy Trouble shooting guide:
HIGH SWR TROUBLESHOOTING
My antenna is a FireStik Firefly FL-4. It is NOT an ungrounded type antenna so it was very important the antenna bracket is grounded to the Jeep frame since the frame acts as the "couterpoise" which allows the antenna to propogate radio waves. Only ungrounded antennas work without grounding to the frame. With an ungrounded antenna, the coax shield acts as the couterpoise. Not as efficient as using the vehicle body/frame as the ground plane but better than nothing if your vehicle has a fiberglass body. (plastic Jeep? fiberglass fender mount?) Also, my antenna is insulated (not bare metal) although where the antenna screws into the bracket is exposed and must not be gounded. My antenna is very flexible and bouces against the spare all the time. Touching the spare is never a problem.
So, ground the antenna bracket to your frame and make sure the center connection remains insulated from the body.
Caveat emptor: This applies to CB not necessarily HAM, satellite, cell boost.
Handy Trouble shooting guide:
HIGH SWR TROUBLESHOOTING
JK Freak
Joined: Apr 2011
Posts: 719
Likes: 0
From: Lakeland, Florida
Touchy touchy
Looking at your mounting bracket, are you sure the antenna base is not shorted to the frame? There should be an insulating washer between them.
Check continuity with an ohm meter like this:
Testing Continuity -- 1996 Firestik® Antenna Company
Check continuity with an ohm meter like this:
Testing Continuity -- 1996 Firestik® Antenna Company
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JK Enthusiast
Joined: Nov 2011
Posts: 216
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From: Montreal
Originally Posted by Sahara Lee
Looking at your mounting bracket, are you sure the antenna base is not shorted to the frame? There should be an insulating washer between them.
Check continuity with an ohm meter like this:
Testing Continuity -- 1996 Firestik® Antenna Company
JK Newbie
Joined: Aug 2011
Posts: 97
Likes: 0
From: QUEENS NY
In spite of what I read here, I have my antenna mounted on the tail gate between the gate and the spare. It has performed great (SWR 1.0 - 1.4 and 5+ mile transmission) for over a year so don't tell me I need to move it. The reason (in my not so humble opinion) the gate mount works on a Jeep (and maybe not so much on a Tahoe) is because the gate is relatively short and the spare rim is not so big... so the majority of the antenna is not sandwiched between metal but extends above.
My antenna is a FireStik Firefly FL-4. It is NOT an ungrounded type antenna so it was very important the antenna bracket is grounded to the Jeep frame since the frame acts as the "couterpoise" which allows the antenna to propogate radio waves. Only ungrounded antennas work without grounding to the frame. With an ungrounded antenna, the coax shield acts as the couterpoise. Not as efficient as using the vehicle body/frame as the ground plane but better than nothing if your vehicle has a fiberglass body. (plastic Jeep? fiberglass fender mount?) Also, my antenna is insulated (not bare metal) although where the antenna screws into the bracket is exposed and must not be gounded. My antenna is very flexible and bouces against the spare all the time. Touching the spare is never a problem.
So, ground the antenna bracket to your frame and make sure the center connection remains insulated from the body.
Caveat emptor: This applies to CB not necessarily HAM, satellite, cell boost.
Handy Trouble shooting guide:
HIGH SWR TROUBLESHOOTING
My antenna is a FireStik Firefly FL-4. It is NOT an ungrounded type antenna so it was very important the antenna bracket is grounded to the Jeep frame since the frame acts as the "couterpoise" which allows the antenna to propogate radio waves. Only ungrounded antennas work without grounding to the frame. With an ungrounded antenna, the coax shield acts as the couterpoise. Not as efficient as using the vehicle body/frame as the ground plane but better than nothing if your vehicle has a fiberglass body. (plastic Jeep? fiberglass fender mount?) Also, my antenna is insulated (not bare metal) although where the antenna screws into the bracket is exposed and must not be gounded. My antenna is very flexible and bouces against the spare all the time. Touching the spare is never a problem.
So, ground the antenna bracket to your frame and make sure the center connection remains insulated from the body.
Caveat emptor: This applies to CB not necessarily HAM, satellite, cell boost.
Handy Trouble shooting guide:
HIGH SWR TROUBLESHOOTING
i had no problem with my 3 or 4ft cb firestick but the 2 meter firestick i bought was another story.
the 2 meter and the gate mount were just to close to the spare and touched it. i couldnt tune that firestick no how once the spare was back on.
JK Junkie
Joined: Mar 2011
Posts: 2,145
Likes: 4
From: Israel
Tires contain steel belts. The proximity of the antenna to the metal in the tire may shield the antenna.
Last edited by GJeep; Aug 17, 2012 at 03:05 AM.