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CB Problems

Yahoo Message Number: 19549
It is rare that I use the CB but just returned from a long trip that I sure needed it a couple of times looking for lost Flying Js. I had replaced the CB that came on the coach b4 we left with a new Cobra hand held (guts under the dash) model. I know these models aren't great but should serve the purpose. I think my problem is in the antenna - I just assumed that the antenna up there was connected to the coax that was connected to the old radio (that one didn't work well either). I also know about the ground plane problems on a fiberglass roof. Guess I'll need to get up there and see if the radio end of the coax is really the same as the antenna. Sure would be nice if this thing had a built in swr adjustment like my old Cobra 29. My local radio shop is no help on a RV - they want to do the work for big bucks.

I have a Cobra 25 "tweaked" running a little power (about 500 total watts) in my PU - now that thing works! (FCC I'm just kidding)

If anyone has any suggestions about my coach radio, I'm all ears.

bojangles5169

'98 Intrigue #10616

Re: CB Problems

Reply #1 –
Yahoo Message Number: 19554
Hi BO,

Please see 19496 - may solve both your problems.
Fred Kovol

Quote from: bojangles5169
>

It is rare that I use the CB but just returned from a long trip

that

Quote
I sure needed it a couple of times looking for lost Flying Js. I

had

Quote
replaced the CB that came on the coach b4 we left with a new Cobra > hand held (guts under the dash) model. I know these models aren't > great but should serve the purpose. I think my problem is in the > antenna - I just assumed that the antenna up there was connected

to

Quote
the coax that was connected to the old radio (that one didn't work > well either). I also know about the ground plane problems on a > fiberglass roof. Guess I'll need to get up there and see if the > radio end of the coax is really the same as the antenna. Sure

would

Quote
be nice if this thing had a built in swr adjustment like my old > Cobra 29. My local radio shop is no help on a RV - they want to do > the work for big bucks.

I have a Cobra 25 "tweaked" running a little power (about 500

total

Re: CB Problems

Reply #2 –
Yahoo Message Number: 19558
Bo,

A few possibilities come to mind....The other end of the coax should be in the tv cabinet if located like my coach. The CB antenna in my coach is also used for the in dash AM/FM radio. The system has a single coax feed from the antenna to a diplexer and from there it splits to feed the CB and in dash radio.
Remove the connector from the antenna and the radio diplexer box and check for any shorts between the shield and center conductor. If short is shown, you likely have a bad connector or damaged coax. It would not be the first time a bad soldering job was done to a connector. If no short, find a local ham radio operator who has an MFJ-259 or 269 antenna analyzer. He can then test the antenna in place for resonnant frequency. Most ham will gladly do it to have the opportunity to talk about their hobby to someone who is a non- ham.

Alternately, another test that could be done is to use an SWR/wattmeter bridge connected between the radio and the antenna.
Do not connect the diplexer in line. If the radio power is very low then suspect the radio. If the reflected power from the antenna is high, then suspect the antenna.

Now connect the diplexer in line and repeat the SWR/wattage check with the SWR/wattmeter connected in line between the diplexer and the antenna. Check for power output. If you had good power output from the radio before the diplexer, but now have very low power after the diplexer, the diplexer is bad.

Jim Hughes, KC4FWS
2000 Allure 30511

Quote from: bojangles5169
>

It is rare that I use the CB but just returned from a long trip

that

Quote
I sure needed it a couple of times looking for lost Flying Js. I

had

Quote
replaced the CB that came on the coach b4 we left with a new Cobra > hand held (guts under the dash) model. I know these models aren't > great but should serve the purpose. I think my problem is in the > antenna - I just assumed that the antenna up there was connected

to

Quote
the coax that was connected to the old radio (that one didn't work > well either). I also know about the ground plane problems on a > fiberglass roof. Guess I'll need to get up there and see if the > radio end of the coax is really the same as the antenna. Sure

would

Quote
be nice if this thing had a built in swr adjustment like my old > Cobra 29. My local radio shop is no help on a RV - they want to do > the work for big bucks.

I have a Cobra 25 "tweaked" running a little power (about 500

total

Re: CB Problems

Reply #3 –
Yahoo Message Number: 19575
Thanks a lot Jim - You may have just solved my problem - Only saw 1 antenna up there so was wondering - also I cleaned out the rats nest (component cabinet) above the steering wheel, got the TV to working correctly by replacing the old selector box with a new one with a built in power amp. Threw away the VCR and installed a new Sony DVD, then ran the audio down to the AUX jack on the dash radio - now at least I have stereo thru the roof speakers on the DVD player - volume controlled by the remote for the radio (Southern Engineering) "Poor folks have poor folks ways". Next I guess I'll reinstall the Hughes satellite eq and figure out how or if that works.

Best Regards,

Glen L Pankratz
Bojangles5169

'98 Intrigue #10616