Intermittant transmit scrambling

This past weekend up in VT I was having some trouble with my CB.

Details of the install: Cobra 18 WX II, with a 4' Firestick on one of LowdPype's passenger side mounts. CB is wired direct to battery. Mount is grounded to body.

The radio received great. Sometimes it'll transmit fine, other times all people hear is a squeal, no matter how close or far. When it does get out distance is aweful. I swapped mic's with another Cobra, and the problem continued.

When I first installed the radio, I borrowed an SWR meter and had decent results getting the SWR around 1.5. I hooked up another CB to the antenna, and it too worked great.

Any thoughts, busted radio?

 

[pickupman]

couple ideas--

1) check your grounds, make sure your radio is well grounded

2) make sure your "second channel monitoring" is either off, or on a different channel

3) check your SWR again


are you running the stock mic, or a power mic? make sure you're running either the stock mic, or a non-amplified mic.

is your radio modded? if so, this may be the problem.... if so - you may need to turn it back down to normal.

 

[Sandy]

Ditto on the Pickupman...

Try running a wire from teh rear panel mounting screw to a good metal ground.

Luck,

 

[V8BoatBuilder]

Thanks for the suggestions.

1) I checked continutity from the antenna bracket to the negative lead on the CB, and it's a perfect 0.0 ohms.

2) Upon further inspection, some of the insulation was worn fron the jacket of the coax, but the inner insulation was OK.

3) The mount bolt was pretty rusted, I'm going to rat shack to pick up a new mount and possibly cable, we'll see what happens.

4) I also opened up the radio, nothing looks burnt or fried, but there are a few potentiometers inside that could be moved. I left well enough alone, any thoughts?

 

[pickupman]

is your coax kinked anyplace?

disconnect your coax from the radio and from the antenna, then check to make sure there is NOT continuity from the shield to the center conductor. you might also check continuity from end to end, if you have long enough leads....

 

[Sandy]

3) The mount bolt was pretty rusted, I'm going to rat shack to pick up a new mount and possibly cable, we'll see what happens.

If your coax has the sheathing and the braid wore through it needs replacing...

BUT, BUT... DON'T GO TO RAT SHAQ for your coax; the coax from there is poor at best. Their outer braid isn't even enough to cover the center insulator and teh Center is made of hard plastic. the Volicity of RS Coax is the worst of all.

Find an Ameteur Radio Shop or Truck Stop, get some Belden RG-8X, some new connectors and adapters. Only get enought to run from teh radio to the antenna with slack in the corner not to pinch anything.

Unless you have the equipment to adjust the inner workings of a CB Radio then leave the adjustments to a Tech.

Luck,

 

[V8BoatBuilder]

Wish I had known that before I ripped open the sealed bag.

However, I'm not sure where else to get coax with PL259's on the ends down on Cape Cod. Only place in MA I know of is You Do It Electronics up in Needham, and it's too far to drive.

 

[Sandy]

Then you do with what you have...

Check the coax before putting it in; center conductor to shield.

Get it tuned for lowest SWR and give a go.

Ltr