CB Tuning question.

[FurryOne]

I'm guessing it's because a 1/2 wavelength is about 18 feet.

...and for some reason they give you a 13' cable.   

[Paniolo]

Does this look right?

At the head of the CB the antenna cable connects with a mini coax. Inside the tour pack it connects to coil that is bracketed to the corner of the grounding plate. Then a cable with a standard "Crimp on O Ring" type connector comes out of the middle of the coil and is screwed onto the back of the antenna base.

Is all of this correct? 

I'm thinking the only way to get an SWR hooked up is if it has that mini-coax, and attach it at the BB radio unit.

I really appreciate your help guys.

[Coyote]

Put the meter up by the radio. You're going to need TNC adapters like these.

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[Paniolo]

Put the meter up by the radio. You're going to need TNC adapters like these.

[attach=0,msg1288321]

Thanks, does the antenna mounting in the tour pack look correct?

[Coyote]

It's a crappy way to do RF but that's the way they did it back then.

[Paniolo]

It's a crappy way to do RF but that's the way they did it back then.

I guess there's no way to improve it,....LOL??

[FurryOne]

It's a crappy way to do RF but that's the way they did it back then.

I guess there's no way to improve it,....LOL??

Only if you want to change antennas.  If you want 2 antennas that look the same, you're stuck with Harley's CB antenna.

[Paniolo]

Put the meter up by the radio. You're going to need TNC adapters like these.

Okay,

Today I went back to the CB/Ham shop in Oakland. I opened up my fairing and the tech was able to use adapters to go from TNC to what he needed to hook up his meter. He checked the SWR on the antenna, and like many predicted it pegged. After checking it out, his conclusion is that I need to replace the cable that runs from the back of the radio all the way down the length of the bike to the antenna.

He said it was exhibiting a grounding problem. I told him it was a Harley and somewhere along the line I'm sure vibration has caused it to fray, or kink, or ground. I asked what kind of a cable I should get and he suggested the OEM HD one. He said it's most likely built to the radios specifications. I asked if it would be better going to another cable than the MoCo low bid one and he still said no.

Does this all make sense? I'm thinking of buying the HD cable and just hooking it up without installing it along the frame just to test

I appreciate feed back.

Mark

[Coyote]

I would really doubt your cable is bad.

Did he test the cable?   

[Paniolo]

I would really doubt your cable is bad.

Did he test the cable?   

I don't know, how does one test a cable? Do you have to remove it from the bike and hook it up to something,  or can it be done in the harness?

He had me wiggle the connections and ground to look for changes. He had me grab and hold the antenna at the base, and then in the middle and then the tip.

[Coyote]

Well a basic continuity test would be the first thing to do. You would need to disconnect it from the radio to do that.

If the cable is indeed shorted, that would be pretty obvious.

[Paniolo]

Well a basic continuity test would be the first thing to do. You would need to disconnect it from the radio to do that.

If the cable is indeed shorted, that would be pretty obvious.

Good point, I have a multimeter tool and can check the continuity. Would that also tell me if the line is grounded somewhere?

Mark

[Jim Bronson]

I know I'm late to this, but without offending anyone, why do you believe the antenna needs tuning? Is the radio not working as well as it did in the past? Did someone tell you it needs tuning? Just curious.

[PoorUB]

as far as tuning, it is pretty difficult to manufacture a CB and slap on an antenna and have operate at 100%. It is not a point of it being wrong, but tuning the antenna to the proper SWR makes it operate better.

It is like buying a new Harley. You can leave it alone, pour gas in it and ride it, or you can get a proper tune and it will run better.

[Paniolo]

I know I'm late to this, but without offending anyone, why do you believe the antenna needs tuning? Is the radio not working as well as it did in the past? Did someone tell you it needs tuning? Just curious.

I bought the bike used, and the CB has never worked properly. When we are in a staging area and choosing our channels, folks can hear me. But on the road all they hear is garble. So I went to this CB/Ham radio shop to check the SWR. The tech hooked the antenna up to the meter and determined that it was grounding somewhere.  So I thought I'd get another cable and try it.

Mark

[Jim Bronson]

If he means the center conductor of the cable is grounded somewhere, then it may have been pinched somewhere along the run from the radio. Just buy a cable with connectors already installed, and replace it. The SWR of the system can be as high as 2:1, and the radio will work fine, although the radiated power will be less. No need to overthink this. I've never owned a bike with a CB, so I can't say how much of a hassle the cable installation is. Just buy the cable from the ham dealer, and they should be able to help you.

[Paniolo]

If he means the center conductor of the cable is grounded somewhere, then it may have been pinched somewhere along the run from the radio. Just buy a cable with connectors already installed, and replace it. The SWR of the system can be as high as 2:1, and the radio will work fine, although the radiated power will be less. No need to overthink this. I've never owned a bike with a CB, so I can't say how much of a hassle the cable installation is. Just buy the cable from the ham dealer, and they should be able to help you.

Well I found the cable on line for $24 plus shipping. Once I get it I will take it back to the shop, hook it up and have him retest it with the SWR. If it's a good reading, then I'll install it on the bike. If not, then at least I have eliminated one avenue.

Any other suggestions are appreciated.

Once again, the only time I use the CB is in groups when I am either on the point, or tail gunner.
Mark

[Coyote]

2006 was the first year for that CB module and HD had lots of bad ones installed. You should have checked the cable. 

[Paniolo]

2006 was the first year for that CB module and HD had lots of bad ones installed. You should have checked the cable. 

Coyote,

You mean 2006 was the first year for that Harmon-Kardon AM/FM/CB/WeatherBand/CD player unit? And lots of those units were bad? I never heard of this before, but if it's true then I will say screw it, and just not use the CB because everything else works okay. I should get that cable in 7-10 days so we'll see how that goes.

Mark

[Coyote]

There's lots of CB modules on Ebay. Just make sure to get one with a later date code (like 2010). It's only a few mins to swap it out. As I said before, I don't think the cable is your issue.

The common complaint when they first came out was distorted audio.

[Paniolo]

There's lots of CB modules on Ebay. Just make sure to get one with a later date code (like 2010). It's only a few mins to swap it out. As I said before, I don't think the cable is your issue.

The common complaint when they first came out was distorted audio.

You're probably right, but all they guy did was hook up his SWR to the cable that runs to the antenna. He didn't do anything with the radio. And based on his findings, the antenna is bad. It was acting like it was grounded. He said in that condition I could neither transmit nor receive.

[Jim Bronson]

You're on the right track. Have the ham store guy test it with the new cable and go from there. If he used an antenna analyzer instead of the radio as the signal source and the swr is still too high, then the problem lies either in the cable or the antenna or a connection.  They probably used an MFJ 259 analyzer or its equivalent which doesn't require a second box at the antenna feed point. Just unplug the cable from the radio and plug the cable into the analyzer and tune the analyzer to the test frequency and watch for the dip. Good luck.

[Paniolo]

You're on the right track. Have the ham store guy test it with the new cable and go from there. If he used an antenna analyzer instead of the radio as the signal source and the swr is still too high, then the problem lies either in the cable or the antenna or a connection.  They probably used an MFJ 259 analyzer or its equivalent which doesn't require a second box at the antenna feed point. Just unplug the cable from the radio and plug the cable into the analyzer and tune the analyzer to the test frequency and watch for the dip. Good luck.

Getting closer,....

i had him test the new cable, and it read only slightly better than the factory one. Then he had me shake the antenna base and move that cable around. He said the SWR dropped from 30 to 5. Although he would like to see 2 or less, 5 is a lot better than 30. Mind you I have no idea what this means, but I'm taking his word for it.

He suggested replacing the antenna base and coil (part 37 in the attachment) and try again. My only issue is that part number 31 is not listed. How do I order that?

[Coyote]

I would really doubt your cable is bad.

Did he test the cable?   

No surprise there.

Just like the cable, an ohm meter can be used to do a basic check of everything in the antenna system on an HD. You need a better tech to look at your problem.... imo of course.

I'd take all of the antenna components apart and clean all the connections. It's a really simple antenna.