Another CB question
02-21-2012 | 08:15 PM
#121
Member
Joined: Feb 2012
Posts: 229
Likes: 0
From: Union County, NJ
Year: 2002
Model: Grand Cherokee
Engine: 4.0L
To the Op: How are you adjusting power on your radio? Just curious... Also what brand/model radio?
02-29-2012 | 11:11 AM
#122
CF Veteran
Joined: Jan 2010
Posts: 1,435
Likes: 67
From: North Riding of Yorkshire, UK
Year: 1997
Model: Cherokee
Engine: 4.0
Well, I just ordered a replacement multimeter off ebay today - God knows where the last one went 
I'll have some answers soon 
The radio I was using for that test was an Anytone-5555 you can turn the TX power up on a pot right on the front panel.
I'll have some answers soon The radio I was using for that test was an Anytone-5555 you can turn the TX power up on a pot right on the front panel.
03-03-2012 | 10:05 AM
#123
CF Veteran
Joined: Jan 2010
Posts: 1,435
Likes: 67
From: North Riding of Yorkshire, UK
Year: 1997
Model: Cherokee
Engine: 4.0
A balun is not going to do you much good. Yes it will "match" the antenna to the radio, but you're not going to transmit too far, and possibly damage your radio.. If both antennas are mag mounts you have to have good contact at the base of the antenna to create your ground plane. If you have access to a DVM, or ohm meter then you can check the continuity from the PL-259 and the antenna itself. First remove the connector from the back of the radio then check from the center conductor to the radiating element, you should see zero ohms, then from the shell of the connector to the base of the mag mount with it too reading zero ohms. If that checks out then measure between the center conductor of the PL-259, and the shell which should show an open circuit (infinity). Personally I would stay away from magnetic mount antennas. Direct mounting is the way to go.
Centre pin to antenna (actually the grub screw because the antenna itself is chromed) 0.6 Ohms
Centre pin to shield: Infinite
Centre Pin to base of magmount: Infinite
Shield to magmount base.... well.. there's a nut that holds the antenna to the base and that gives 0.7ohms. The base itself is painted/anodized and where that's patchy I also get 0.7ohms. I get infinity through elsewhere. The magnet itself gives infinity and the whole thing sits on a rubber pad which of course doesn't conduct.
The magmount is a 7" mount from this page
http://www.thunderpole.co.uk/magnetic_mounts.htm
and the antennas are:
one of Mini Orbiter (baseload)
and one these for static use (DXing on hilltops etc)
I've got another magmount that I haven't tested yet but gives the same results.
I'm confused
Last edited by Morat; 03-03-2012 at 10:09 AM.
03-03-2012 | 01:39 PM
#124
Member
Joined: Feb 2012
Posts: 229
Likes: 0
From: Union County, NJ
Year: 2002
Model: Grand Cherokee
Engine: 4.0L
OK, I've got a new multimeter....
Centre pin to antenna (actually the grub screw because the antenna itself is chromed) 0.6 Ohms
Centre pin to shield: Infinite
Centre Pin to base of magmount: Infinite
Shield to magmount base.... well.. there's a nut that holds the antenna to the base and that gives 0.7ohms. The base itself is painted/anodized and where that's patchy I also get 0.7ohms. I get infinity through elsewhere. The magnet itself gives infinity and the whole thing sits on a rubber pad which of course doesn't conduct.
The magmount is a 7" mount from this page
http://www.thunderpole.co.uk/magnetic_mounts.htm
and the antennas are:
one of Mini Orbiter (baseload)
and one these for static use (DXing on hilltops etc)
I've got another magmount that I haven't tested yet but gives the same results.
I'm confused
Centre pin to antenna (actually the grub screw because the antenna itself is chromed) 0.6 Ohms
Centre pin to shield: Infinite
Centre Pin to base of magmount: Infinite
Shield to magmount base.... well.. there's a nut that holds the antenna to the base and that gives 0.7ohms. The base itself is painted/anodized and where that's patchy I also get 0.7ohms. I get infinity through elsewhere. The magnet itself gives infinity and the whole thing sits on a rubber pad which of course doesn't conduct.
The magmount is a 7" mount from this page
http://www.thunderpole.co.uk/magnetic_mounts.htm
and the antennas are:
one of Mini Orbiter (baseload)
and one these for static use (DXing on hilltops etc)
I've got another magmount that I haven't tested yet but gives the same results.
I'm confused
03-03-2012 | 05:28 PM
#125
CF Veteran
Joined: Jan 2010
Posts: 1,435
Likes: 67
From: North Riding of Yorkshire, UK
Year: 1997
Model: Cherokee
Engine: 4.0
I'll try it!
I don't have an SWR meter so I was using the one built into the radio but I did have it measured at a shop with a professional meter (some kind of all-in-one device that I didn't get my hands on) which gave the numbers in the original post.
There's a nut on the base of the mount that I could use to clamp a wire to use as a ground, is that where we're going if the shield to Jeep reading is too high?
thanks for your help, it's really appreciated.
I don't have an SWR meter so I was using the one built into the radio but I did have it measured at a shop with a professional meter (some kind of all-in-one device that I didn't get my hands on) which gave the numbers in the original post.
There's a nut on the base of the mount that I could use to clamp a wire to use as a ground, is that where we're going if the shield to Jeep reading is too high?
thanks for your help, it's really appreciated.
03-03-2012 | 07:07 PM
#127
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Originally Posted by UsmclovesXJ
Running dual 102in whips worth it or no?
03-03-2012 | 07:33 PM
#129
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Originally Posted by UsmclovesXJ
Planed on running a 8ft
Where the radio antenna would have went.
And on the rear left bumper/ brake light.
Where the radio antenna would have went.
And on the rear left bumper/ brake light.
03-03-2012 | 07:46 PM
#131
CF Veteran
Joined: Aug 2010
Posts: 8,387
Likes: 1
From: The Florida State University
Year: 2001
Model: Cherokee
Engine: I-6 4.0 L
03-03-2012 | 07:48 PM
#132
CF Veteran
Joined: Feb 2011
Posts: 3,500
Likes: 0
From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
Originally Posted by cf1k1
I have a 102" SS from radioshack whip plus a 6" radioshack spring. The wilson fiberglass antenna I had was a SWR of about 1.6, the SS+spring was 1.4 . I knew exactly which one I was keeping...
Theres pics in this thread of it
03-03-2012 | 07:50 PM
#133
CF Veteran
Joined: Aug 2010
Posts: 8,387
Likes: 1
From: The Florida State University
Year: 2001
Model: Cherokee
Engine: I-6 4.0 L
Originally Posted by askingxforxit
I made an 11.5" extension for my 4' firestik and my swr is about 1.1
Theres pics in this thread of it
03-03-2012 | 07:52 PM
#134
CF Veteran
Joined: Aug 2010
Posts: 8,387
Likes: 1
From: The Florida State University
Year: 2001
Model: Cherokee
Engine: I-6 4.0 L
Just saw the extension. Good idea but bad design, no trying to be an **** or anything. I think a 6"spring, plus a 5.5" extension then the antenna would be better. Adding the extension as is is limiting flexibility of the system. Great idea though.