AB15 for CB setup

[ramcatdoc]

Hey, y'all! I've been reading the various threads about CBs and AB15/MS116-117-118 combinations. I have an AB15 consisting of the upper and lower ceramic base, a rubber gasket, a circular metal plate with a grounding tape, and a clamp strap soldered to the loose end of the grounding tape. Of course, I have the antenna core as well.

So..., not being an electrical type, in what order do I reassemble? Where does the gasket go in relation to the grounding plate and the mounting bracket, and where does the loose end of the grounding tape go?

Any help in nontechnical language would be great!

Thanks,

 

[quickfarms]

Subscribed

 

[wsucougarx]

Hope this helps

 

[cucv1833]

Hey, y'all! I've been reading the various threads about CBs and AB15/MS116-117-118 combinations. I have an AB15 consisting of the upper and lower ceramic base, a rubber gasket, a circular metal plate with a grounding tape, and a clamp strap soldered to the loose end of the grounding tape. Of course, I have the antenna core as well.

So..., not being an electrical type, in what order do I reassemble? Where does the gasket go in relation to the grounding plate and the mounting bracket, and where does the loose end of the grounding tape go?

Any help in nontechnical language would be great!

Thanks,

Im using the AB15/MS116-117-118 set up with a Cobra classic CB I cut the antenna down to 108" total.

On mine i installed the 2" mounting plate between the 2- ceramic peices. The rubber gasket between the mounting plate and the fender mount.
The grounding clamp is secured to the cable connection at the antenna base.
I also ran a small wire from that grounding clamp to a mounting bolt on the truck.

It works great for me and the signal looks good on the SWL meter.

Im using the Cucv antenna mount.

Sorry no close up pics now
http://www.steelsoldiers.com/members/cucv1833-albums-m1009-picture18179-combo.html

 

[ramcatdoc]

Thanks to both of you for the comments and the photo. I'll let people know how it goes.

 

[nattieleather]

The gasket goes on the upper side of the mount and the grounding plate goes on the underside. As stated the hoseclamp goes around the PL-259 antenna coax connector. An additional ground wire like CUCV1833 stated is not a bad idea. 108-110 inches is about the right length. If you cut the top antenna section make sure you seal it up or rain and moisture will get inside the antenna because the antenna section are basically copper tubing.

 

[ramcatdoc]

Thanks, Nattieleather. This will help.

I have read several posts indicating how long their antennas are. As I understand it, the length of 110 inches INCLUDES the base, correct? (about 106 inches for the antenna alone).

 

[cucv1833]

Thanks, Nattieleather. This will help.

I have read several posts indicating how long their antennas are. As I understand it, the length of 110 inches INCLUDES the base, correct? (about 106 inches for the antenna alone).

Correct
110" from base to tip of antenna.
What CB are you using?
You may want to put a SWR meter on it and cut a little at time. Make sure you got a good ground to the grounding strap. Thats why I added the extra piece of grounding wire. I kept cutting and the reading wouldnt change. (wasnt grounded)

Heres a few threads and opions on CB's and the AB-15

Good luck

http://www.steelsoldiers.com/cucv/77117-military-antenna-cb-radio.html?highlight=AB-15

http://www.steelsoldiers.com/cucv/55862-1729-vrc-antenna-cb-conversion.html?highlight=AB-15

http://www.steelsoldiers.com/cucv/76014-cb-radio-install-need-some-ideas.html?highlight=AB-15

 

[ramcatdoc]

Correct
110" from base to tip of antenna.
What CB are you using?


I'm using a Cobra 29 XL. Have not decided whether to connect power to battery or to fuse box. Any suggestions?

 

[cucv1833]

I'm using a Cobra 29 XL. Have not decided whether to connect power to battery or to fuse box. Any suggestions?[/QUOTE]


My CB came with a bus fuse already inline. So I hooked mine up to the battery.
I prefer to switch it on-off at the CB itself.

I have a seperate 12v fused junction box in the cab that I run all my extra goodies off of. I only run my stereo off the Factory fuse block.

 

[Matt65]

..... Have not decided whether to connect power to battery or to fuse box. Any suggestions?

I picked up a cigarette lighter adapter from the Pilot truck stop to plug in the back of my 29. It has an inline fuse. For a factory radio (no amp) it works well and is very portable from one truck to the next. I use a Wilson 1000 with good results.

 

[bshupe]

Anything but straight from the battery is going to introduce noise into the line causing and increase in the "noise floor" you hear. With the dual alternators this could be magnified greatly although I dont have first hand experience with a CB and dual alts. If you have to run from the factory wiring then put a ferrite choke on the power lead. You might need one even if you come off the battery direct.

 

[cucv1833]

Hey, y'all! I've been reading the various threads about CBs and AB15/MS116-117-118 combinations. I have an AB15 consisting of the upper and lower ceramic base, a rubber gasket, a circular metal plate with a grounding tape, and a clamp strap soldered to the loose end of the grounding tape. Of course, I have the antenna core as well.

So..., not being an electrical type, in what order do I reassemble? Where does the gasket go in relation to the grounding plate and the mounting bracket, and where does the loose end of the grounding tape go?

Any help in nontechnical language would be great!

Thanks,

Here you go got a pic of my AB-15 base mount and CB install.
The yellow wire is the extra ground wire I added. You may not need that.

Good luck let us know how you come along with the install

 

[ramcatdoc]

Sorry, this is a duplicate post of the one just below it.

 

[ramcatdoc]

So....
I have my AB-15 antenna set up with the rubber gasket on top of the mounting bracket and the grounding plate under the mounting bracket. The hose clamp is well-atached to the PL-259 adapter screwed into the base of the AB-15. And I have placed a second ground wire from the PL-259 to a mounting bolt on the bracket. I have the CB well-mounted on the dash, with power directly from the battery.

I am using a Cobra 29 LX, which has an integral SWR tester. I have good power to the unit and good output, according to the radio self-test function in the CB. However, I receive an "antenna fail" error when I test the antenna. The SWR reads less than 1:1.5 on channel 1, 20, and 40. However, despite this, when I push the transmit button, I get "antenna warning" on the screen.

I have rechecked both ends of my antenna cable. It was 18 feet long, and I did cut about 2 feet off it. My whip antenna is still about 113 inches long, having cut some off. I did not want to cut more off until I was sure I was actually getting a good antenna signal.

Any suggestions? I have tried to contact Cobra directly, but they "will call me back within one business day".....

Thanks

 

[tennmogger]

Most likely what is happening is that the CB is reducing power to protect itself from high SWR, and only showing low SWR. 113 inches is quite long.

You really need to have an external SWR meter. Cheap ones are on 'that auction site' all the time for under ten bucks. IMHO the older ones are best.

One trick to use for tuning the antenna length is to skip testing back and forth between channel 1 and channel 40. Channel 1 is on the lowest frequency, 40 the highest. If the SWR is better on the lower frequency (longer wavelength) then the antenna is too long. To the contrary, if SWR is best at channel 40, then the antenna is too short already.

Bob WB4ETT

 

[cucv1833]

I think I tuned mine on ch-20 I believe thats what Cobra website tells you.
I see you put a 2nd ground wire from the hose clamp back to the bracket?

My 2nd ground cable goes from the grounding hose clamp thats around the Pl259 and secured to the bolt that holds the tire carrier on on the bed rail.

Before I adding that grounding cable My SWR meter was pegging out (High SWR)

When I adding the grounding wire the way I did. It worked perfect.

Just a thought Im far from a expert but that worked for me.

 

[nattieleather]

Double check the gournd strap. On the bolt that the extra ground wire is attached to make sure you have a star toothed washer on both the bolt head and the nut. This will help get a good ground. Or if you really want it to ground well...grind that spot to bare metal, install nut, bolt and star washer then prime and repaint. I think you are going to need to lower the antenna a little more. Remeber that the part inside the porciline is also part of the total length as is the rubber "spring" part.

 

[cucv1833]

So....
I have my AB-15 antenna set up with the rubber gasket on top of the mounting bracket and the grounding plate under the mounting bracket. The hose clamp is well-atached to the PL-259 adapter screwed into the base of the AB-15. And I have placed a second ground wire from the PL-259 to a mounting bolt on the bracket. I have the CB well-mounted on the dash, with power directly from the battery.

I am using a Cobra 29 LX, which has an integral SWR tester. I have good power to the unit and good output, according to the radio self-test function in the CB. However, I receive an "antenna fail" error when I test the antenna. The SWR reads less than 1:1.5 on channel 1, 20, and 40. However, despite this, when I push the transmit button, I get "antenna warning" on the screen.

I have rechecked both ends of my antenna cable. It was 18 feet long, and I did cut about 2 feet off it. My whip antenna is still about 113 inches long, having cut some off. I did not want to cut more off until I was sure I was actually getting a good antenna signal.

Any suggestions? I have tried to contact Cobra directly, but they "will call me back within one business day".....

Thanks

Any updates? Let us know if you got it working

 

[ramcatdoc]

Well, y'all, I've done everything y'all suggested, and I still can't get a signal!

I have put new PL-295 connectors on the RG-58 antenna cable, which is also new, (although I cut 3 feet off to keep from coiling it in the truck). I have star washers on the bolt and nut to which I have put the second ground wire. This is a new wire with copper core. The antenna, including the 4 inch ceramic base, is 110 inches long. I cleaned off the ground plate so it would make better contact with the truck mount. I have a red rubber gasket between the upper half of the ceramic base and the and the mounting bracket. The ground plate is between the underside of the bracket and the bottom half of the base. The hose clamp is firmly attached to the PL-295 connector which is firmly attached to the bottom of the base. The second ground wire is also clamped with the hose clamp to the PL-295.

According to the internal radio check, I have plenty of power in and out. My SWR meter reads 1.2:1, but I still get "antenna fail" when I do the internal antenna test. I don't hear anything on the CB bands -- no chatter at all. When I key the mike, the screen says "antenna warning." I can get fairly good WB reception, though with a fair amount of constant static.

The guy at R---- S----, where I got my PL-295 connectors, suggested I should be able to hear general CB chatter no matter how poor my SWR reading is. He suggested their might be a radio problem, but it's fresh out of the box. Could this be true? Or could I have a faulty antenna?

I'm hoping there is an easy fix, but I am beginning to really wonder what gives!

This is all very new territory for me. I think I'm being logical about it, but I just don't know what else to try! Any of y'all stay at a Holiday Inn and have some answers???