CB Radio stopped working

[fluffyms]

All relating to my '98 HR 38WDS -

My coach has a factory installed Maxon MCB-10A which was working just fine until about a couple of weeks ago. It powers up, meaning the lights on the channel window show it's on, but I suddenly don't get any reception (can't send or receive). The channel window show channels, and when pressing the transmit button, the transmit light glows the normal red. But that's it.

I've checked every connection I can think of....but didn't go on the roof, and in all honesty, don't really want to, to check the antenna.

Anyone have any thoughts as to what the possible cause of my problem is???

[cruzbill]

Could you have driven under a low-lying tree limb? IF your radio is like mine, there is a graph that tells you how strong a signal you are receiving, kinda like a VU meter on a stereo. Anyway, if that graph is moving up and down, that would tell you that you are receiving a signal-antenna good, speaker bad. Other than a broken antenna or bad speaker-Do you have a CB shop (truck stop) nearby?

[manderson2228]

Turn the SQL knob both directions see if you hear anything. Also mess with the rf gain knob that might of gotten adjusted too. What model radio do you have?

[nehog]

Two tests I'd do... (but I have the equipment...)

1. I'd check SWR on the antenna. If you don't have an SWR bridge then,
2. A quick test with a second CB set can help.

Personally I suspect it is 'dead' but it could be the antenna line is bad. If you can get at the antenna connector remove the cable and stuff a piece of (strip the insulation about 1/2" first) into the antenna connector on the set. Mash it in good, so it makes connection. Have the wire about 108" long, and just drape it near the windshield. Do you get any reception at all? If yes, then the antenna/cable may be dead.

[Mr_D]

Originally Posted by cruzbill

Could you have driven under a low-lying tree limb? IF your radio is like mine, there is a graph that tells you how strong a signal you are receiving, kinda like a VU meter on a stereo. Anyway, if that graph is moving up and down, that would tell you that you are receiving a signal-antenna good, speaker bad. Other than a broken antenna or bad speaker-Do you have a CB shop (truck stop) nearby?

That meter is a SWR (Standing Wave Ratio) meter. I have one of the stand alone meters in my workbench someplace from back when I used them.

[nehog]

Oops, got on the roof of my rig to fix the AC and noticed my CB antenna is missing! It was there but I guess it decided to stay in Vermont, probably it found it liked the low hanging tree branches enticing?

Anyone know how long the factory antenna is, and how many turns on the coil/spring section? I'd like to get close before I start tuning it... (I have antennas but none are factory for this setup...)

[cruzbill]

PO had a firestick antenna (24"?) so I replaced with another, it broke off too. So I found a spring base and metal whip which I used to replace the Firestick. I tested the ground, it was good. I couldn't get a great SWR, it took minor (1/16") adjustments of the whip length (in and out and tightnen allen screw).
I'd like to put up a ground plane plate (24" dia or so) up there and see if that makes a difference. I read a very interesting article about ground planes, they are not what I thought.

Hi Bill
CB frequencies are in the 27mhz range, this is the top end of the HF band. Yes, CB's do require a ground plane / counterpoise. Of course many CBers simply use the frame of their vehicle, but that is actually a bad idea since it is DC negative. Having DC negative on your ground plane causes a lot of ignition and electrical noise in your radio, even when filtered to a degree, plus it diminishes the potential signal some too. The KISS-SSB would be an over kill for such a ;limited frequency range but yes. it would work. However a better alternative would be a length of wire measured at 8'8" as a counterpoise radial and it will work just as well. This wire needs to be connected to the base shield connection of your whip antenna and do not allow the base bracket to be in contact with any frame metal that may have DC negative on it. This radial wire would need to be below the whip antenna, (that's why its called a ground plane, it has nothing to do with earth ground). The counterpoise repels the high RF off of the antenna of choice. Divide the frequency by 234 and that gives you a half wave length resonate length. You do need to be able to adjust the length of the antenna to get your best SWR at the channel 12 (middle) frequency.

Hope this helps, Carl Nichols RadioTeck / KISS=SSB

[WesPearson]

Don't want to hijack the thread but I also lost my cb antenna to a low overhead ag inspection station entering Calif. I found a new antenna but short of running a new cable with the big connector though the roof I need to splice the rg-56 cable. I have located the proper male and female connectors but they require a special crimper to connect the center lead. They cost between $50-100 dollars. The connector total less then $5. The antenna end I could have done at the electronics shop but the other end is on the roof of the coach. I'm sure the cost of having a tech come to the coach and crimp the center lead would be more then the cost of the crimpers. Any ideas? I tried soldering the center lead but l'm not that good with an iron. I've considered soldering the two ends together with heat a shrink covering but I know antenna leads are sensitive to bend such so would that work? It's not worth very much to get the cb up and running again.

[manderson2228]

So a lost antenna will certainly create reception issues!!!

[Isaac-1]

Originally Posted by WesPearson

Don't want to hijack the thread but I also lost my cb antenna to a low overhead ag inspection station entering Calif. I found a new antenna but short of running a new cable with the big connector though the roof I need to splice the rg-56 cable. ...

I suggest you read up on ground plane and no ground plane CB antennas, and if you don't have a metal roof, you need to read up on no ground plane cables as they can't be effectively spliced since they must be a very precise length to operate correctly (within 1/4 inch of a certain length)

[WesPearson]

I have an aluminum roof so ground plane isn't a problem. Just wondering if I can splice the lead-in rg-56 cable?

[fluffyms]

Got a lot of interesting information from you guys relating to my CB radio that stopped working...BUT...I've tried to trace the antenna wire thru the dash going to the roof. Guess what - somehow I lost trace of the antenna wire when it got to the maze of wires going under the dash. I thought it would be routed via the area where the TV antenna connection(s) would be but thats where I'm lost.
Too many wires and none that I could find that go anywhere near to where I thought the loom of wires relating to the radio, tv, etc would be routing to the roof. Anyone have any thoughts on what I should be looking for ???
I want to make sure it ( the antenna connection ) didn't somehow get disconnected.
Another point - after all this time, I just realized that I have 3 antennas on the roof - I know one is for the am/fm radio, one is for the CB - what's the third one for ? You'd think I would have noticed that before but didn't. Checked the owners manual also, and it didn't give me any information on 3 antennas.

[Isaac-1]

Get a cheap signal injector then you should be able to trace the wire something like
https://www.amazon.com/Extech-TG20-W.../dp/B00APD16D2

[cruzbill]

For Wes, Maybe drive by and see if these guys can help;

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