CB antenna issues

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canuckrv

Well-known member
Joined
Apr 1, 2013
Posts
464
My new to me Motor home came with a Cobra 18 wx st CB.
Is this a good unit?
I was getting bad reception (really bad on the Weather Radio) until I started to take the antenna connection from the back, when I loosened the plug just a bit it worked great but if done up tight it will not, any ideas?
As always thanks
Jerome
 
Not sure about the problem, but back in the 70s when CBs were big, we used to have to match the antennae with the radio with some sort of meter...Thats about all I know about it
 
Well CB and Weather are totally different bands (27MHZ (CB) 162.5 (Weather)).

Usually when messing with the PL-259 Connector makes a difference it is one of the following.

1: Improper attachment of the PL-259 (Failure to make sure the little point on the plug goes into a notch on the socket and failure to properly tighten)

2: Bad connection coax to plug

3: Some antennas just do not work well on both frequency bands.
 
1: Improper attachment of the PL-259 (Failure to make sure the little point on the plug goes into a notch on the socket and failure to properly tighten)

It is in the notch on the socket, if it is properly tightened it stops working almost as if it is going in to far, should there be a washer or some thing at the "bottom" of the plug?
 
I was playing around with it again Now the CB does not have reception at all but I can still get the weather radio.
 
it must be well grounded then as there is no noise even with the squelch up all the way. ;)
 
canuckrv said:
My new to me Motor home came with a Cobra 18 wx st CB.
Is this a good unit?
I was getting bad reception (really bad on the Weather Radio) until I started to take the antenna connection from the back, when I loosened the plug just a bit it worked great but if done up tight it will not, any ideas?
As always thanks
Jerome
You must be removing the ground connection on the cable at the radio when you do that. If that makes reception better, only three  things can be wrong.

1. There is no connection between the antenna and the cable at the far end. So you're using the cable as an antenna until the shield  is connected to the radio and then the cable can no longer be acting  as an antenna. So then it works MUCH better, but not nearly as well as it should, when the shield at the radio is not connected to the CB unit. So when you loosen it, you get at least some reception. I would bet this is your problem, so check the opposite side of that cable where the antenna is on the roof or whatever.

2. The cable (or connector) has a short in it, so when you remove the ground it can use the entire length of the cable and antenna as one antenna.

3. The antenna is so far off from the correct resonance for that  frequency, it appears as a short until you remove the ground connection from the cable to the radio.

Either way, the problem is the antenna or the cable, or between them. Most likely near the antenna itself (unfortunately).

And IMO, all CB units are about the same. But I see that the Cobra 18 wx costs around $65.00.

Is that designed to use the CB antenna for the weather radio?

-Don- (professional radio tech for two more months and then I retire!)  Reno, NV
 
I think I got it fixed. I squeeze the mail part of the plug to make it slightly out of round so that it fit tighter and by rotating it I was able to get it so that it pick up both the Weather radio and CB signals.
On the antenna wire there is two wires that come from the plug one long one that goes to the antenna outside and one short one that runs about 6 inches and is capped off.
is this the correct wire?
 
canuckrv said:
I think I got it fixed. I squeeze the mail part of the plug to make it slightly out of round so that it fit tighter and by rotating it I was able to get it so that it pick up both the Weather radio and CB signals.
On the antenna wire there is two wires that come from the plug one long one that goes to the antenna outside and one short one that runs about 6 inches and is capped off.
is this the correct wire?

Sounds to me the coax which you are referring to as "antenna wire" is set up for dual antennas, you need to get a single piece of coax  like this one on ebay > http://www.ebay.com/itm/ASTATIC-18-FT-RG8X-CB-HAM-RADIO-ANTENNA-COAX-CABLE-W-PL259s-/231074534736?pt=US_Radio_Comm_Coaxial_Cables_Connectors&hash=item35cd1d9550


I said earlier that a ground is the most important part of a cb radio  , you should consider a lip mount to put on your rv....  similar to this...    as a matter of fact if you buy this it will be all you need , just screw in your antenna...
http://www.ebay.com/itm/CB-HAM-Antenna-Trunk-Lip-Mount-Kit-4M-RG58-Cable-PL259-/111177952289?pt=LH_DefaultDomain_0&hash=item19e2b8ec21

 
Ok So I finally got out to play around with the CB with the antenna screwed down tight I get good CB reception, but no weather radio, if I unscrew I get good weather radio but no CB. I have tried to contact Cobra but no response. Does anyone know if there is a special antenna for this radio? to do both?
Does it still sound like a grounding issue? if so would an antenna like this work for both?
http://www.rightchannelradios.com/firestik-ngp-antenna-side-mount-kit-right-channel-radios.html
thanks
 
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