One annoying issue/problem...

[RedRider]

I installed a new Cobra 29 in my pickup, problem is unless I use a magnet mount antenna, the damn ANT warning light keeps coming off, and I'm about to my wits end with the damn thing.

I have this stupid mount grounded in 3 places (4 if you include the bolt its actually hooked to) and it still turns that damn light on. SWR is about 1.2:1, even less maybe, but that stupid **Censored** light keeps coming on... [pictures:






Any suggestions?

[RedRider]

Antenna is a Wilson 2000 Trucker btw...

That mount isn't the one I'm going to use more than likely, but its just to test with, because if I can't get this ***** light to turn off I'm going to take the radio back and say screw CB's all together.

[MDYoungblood]

Your antenna looks like it is well grounded, have you checked the coax to see if it has a problem, it may have a broken center conductor, I had that problem with an old magnet mount where the coax went thru the door jam. Sitting still it was fine, but moving it separated. Greg

[Sporty Mike]

Is this a new Cobra 29 LX LE?? or is it a 29 LTD? Was the radio setup or tuned by a tech? Did you by it from a CB shop?
These are all important factors before I offer up a possible , yet simple resolution.


Mike

[51]

if his vswr's are 1.2 or lower its probably not the antenna system at fault. i have yet to see those antenna warning lights calibrated correctly from the factory. they just put it in a general area. i have a couple that wont come on til an vswr of 3.0, i have one that comes on at 1.3, heck i got one that comes on at 4.0. screw the light and trust your vswr meter. think of the led as a modulation light as far as all those wires u got grounding your mount, i would junk that and go with some fat braided ground straps....

[RedRider]

if his vswr's are 1.2 or lower its probably not the antenna system at fault. i have yet to see those antenna warning lights calibrated correctly from the factory. they just put it in a general area. i have a couple that wont come on til an vswr of 3.0, i have one that comes on at 1.3, heck i got one that comes on at 4.0. screw the light and trust your vswr meter. think of the led as a modulation light as far as all those wires u got grounding your mount, i would junk that and go with some fat braided ground straps....

Hmm... black electrical tape light cover? haha. Yeah, I just threw those wires and such together just to test stuff, do the ground wires look good though? Do I need to add more, or change something?

Your antenna looks like it is well grounded, have you checked the coax to see if it has a problem, it may have a broken center conductor, I had that problem with an old magnet mount where the coax went thru the door jam. Sitting still it was fine, but moving it separated. Greg

I've used two different types of coax, 18ft with dual 259 ends, and 9ft with a ring connector end... as well as the magnet mount. Both of the first two coax's worked well with previous setups.

Is this a new Cobra 29 LX LE?? or is it a 29 LTD? Was the radio setup or tuned by a tech? Did you by it from a CB shop?
These are all important factors before I offer up a possible , yet simple resolution.


Mike

Its a Cobra 29 Army Edition... It wasn't tuned by anyone, its all stock. Bought it from a truck stop.

I'm probably going to order a stainless hood mount for it though... do they make a 9ft fire-ring connector coax?

[MDYoungblood]

Firestick makes one (9' Fire-Flex® Coax w/ Fire-Ring SKU # K-8r9 )

['Doc]

You're gonna love this!
That SWR just isn't as important as most people think. Or really, people have the wrong idea about SWR. The only thing SWR tells you is how well the match is between two things. It depends on what two 'things' the meter is mounted between! If that SWR meter isn't mounted between the feed line and the antenna's feed point, it can tell you nothing about how well that antenna is matched (which is only half of tuning an antenna). If that meter is placed at the transmitter's end of that feed line it can only tell you how the match is between the transmitter's output point and the whole antenna system which includes the feed line -and- the antenna.
An SWR meter is a very 'dumb' thing. It can recognize 'impedance' as a whole, but has no idea what that impedance actually consists of. Impedance consists of resistance, and two kinds of reactances, a (+) kind of reactance that's inductive (coilcs), and (-) kind that's capacitive (capacitors). A 1:1, or 'perfect' impedance is 50 ohms of resistance and zero reactances. If you have the right 'size' of those two kinds of reactances, (+) and (-), they add together and give you zero, they nullify each other leaving only resistance. (Neat way of going about it, huh?) Now the 'kicker', the 'catch', two of them actually. First, that resistance thingy. No antenna has a 'natural' input resistance component of impedance of 50 ohms. The second 'catch' is that resistance, no matter what it's value is, when combined with reactance, no matter what it's value is, is ever just the value of 50 ohms. Or stated another way, when you combine resistance and reactance there's no way an SWR meter can tell you what each of those 'values' are, that SWR meter can only tell you the combined value, so you have no idea which of those components you should 'adjust' to make the @#$ thing really be 50 ohms of resistance and zero reactances. (Zero reactances is the definition of reosnance, by the way.) So, using -only- an SWR meter to 'tune' an antenna is pure guess work. Not a very 'happy' thought, huh? Sorry, but it's true. It's possible to get very 'close', but no cigar...
Is there something that can do all that measuring of individual components of impedance? Yes, but it isn't cheap, and certainly not as common as SWR meters...
- 'Doc

[paBullwinkle]

honestly all the grounding wires look excellent. if you want to check to ground take a ohmmeter and put it on the lowest setting and read from the out side to a solid ground. should get a low resistance. also might want to check that center isn't shorted to ground.

['Doc]

Those "grounds"...
are totally worthless. What's the difference between them and just measuring the resistance between two points of the same conductor? It isn't a 'DC' ground, or a 'DC' low resistance you should be worried about. It's an 'RF' "ground" (that means it's 'AC' and frequency related), which you can't measure with an ohm meter.
Instead of adding those wires from where they are, how about making sure that fender is electrically connected to the rest of the vehicle and frame? If that fender is metal, why not use it as the 'conductor' instead of a separate wire? Because copper is more 'conductive' than steel?? That's another 'silly' idea...
- 'Doc

[MDYoungblood]

RedRider,
If you think the problem is not with the antenna setup than you need to go to the radio. I would put a dummy load at the antenna end of the coax and do your test. If you see the same problem than go right to the radio and test. It is going to be a trial and error thing since most of us are not electrical engineers with sophisticated electronic devices to check resistance,reactance,impedance, etc.
Greg

[North Texas Mudduck]

once a radio is tuned
the swr warning needs to be adjusted or sometimes it get adjusted without knowing
then it needs to be adjusted back
i could be wrong but some are set at like a 1.5 swr
then some people go in a just start turning everything waiting for some kinda movement

now the good thing coulb be that the antenna system is fine and the one who did the tune up just threw the swr warning light adjustment off and needs the back side of his pants raised up off the floor a few times

and a internal meter on radio is not very accurate as to a external meter for swr .
well then some folks like to mess with the adjustments in those as well.

the blue wire what are those for?
is that what you are calling ground wires?

find you some old rg8 or 213 coax pull the guts out and use the braided strap for strapping