I bought the Cobra 29 WX NW ST radio. Here's a pic:http://www.rightchannelradios.com/bmz_cache/9/928191e46de89f815f9fffc2a323aad5.image.700x443.jpg

I have no idea what the following things on the radio are:
1) The first know goes from S/RF to SWR to CAL. I'm assuming S/RF means squelch/RF Gain. What are the other two?
2) Second switch says NB/ANL to ANL to OFF. No clue there whatsoever.
3)Farthest right knob (other than the channel control knob) says SWR CAL. Again, what is that?
4) DYNA on the bottom of the second knob is...?

Also, bought mine used, so that may be why, but my Night Watch function doesnt seem to work. I can't read the knobs at night at all. It is because mine's old right?


Help! please and thanks!
:aufkopfhauen-big:

Here's a link to the Instruction manual (http://www.cobra.com/downloads/manuals/29WXNWST.pdf). It might help a bit.

The only one of those abbreviations I'm familiar with is SWR, which means standing wave ratio. It's a measure of how well your antenna, antenna cable, and ground plane are matched to your particular transmitter.

Based on that, I would guess that CAL is short for calibration.


Someone else who is more familiar with CB's and maybe even that model in particular will chime in shortly. Hope I could get you started in the meantime!

I have that same model later today ill go look at it.. but you may have the light knob turned down.. it happens to me some time.

cal is for calibration set the switch to cal the press the talk button then use the cal knob to get the signal strength gauge to point to cal.

I hope that helps some what.

S/RF to SWR to CAL.

SWR (Standing Wave Ratio) calibration is done to properly adjust the length of the antenna and to monitor the quality of the coaxial cable and all connections. This calibration or "tuning" is to get the best performance from your radio .

While holding mic button adjust the SWR/CAL knob so that the meter needle swings to the “CAL” mark on the meter. While still holding down the mic button, set the S/RF SWR CAL switch to SWR. When switched to SWR position the meter needle should ideally be as far to the left as possible.
Anything over 3 is not good and you can damage your radios transmitter..

When the switch is on S/RF the meter swings proportionately to strength of incoming signal when receiving. Only the squelch knob means squelch.

The RF Gain knob is used to optimize reception in weak signal areas (or bring in weak signals from folks who do not tune their radios). Turn counterclockwise to reduce gain.

The ANL is the Automatic Noise Limiter. This helps reduce noise created by the vehicle’s electronics (usually the alternator ).
NB/ANL means a Noise Blanker is also activated, providing increased noise filtration.
OFF position all noise filtration will be turned off.

DYNA knob is is used for setting the setting Dynamike. This controls the microphone sensitivity (outgoing audio level) and to adjust the PA speaker (if you have one) volume.

A PDF of the manual for that radio is HERE (http://www.cobra.com/downloads/manuals/29WXNWST.pdf)

Tom, your the best!

Just remember, when using the SWR CAL, make sure you're in a way open area. Any trees, hills, walls, other cars, etc around you will affect the SWR, so when you think you have it set all nice and good (say at 1.5).. when you head out and go to use it the actual SWR you have at that time will be way off (Typically higher if you tuned it in say a garage)

Yes^^^
If we’re going into detail on tuning your radio…your SWR will change when you change the channel you are operating on sooo, tune it on channel 20 unless you are planning to use the same channel all the time. In that case tune it on that channel.

S/RF to SWR to CAL.

SWR (Standing Wave Ratio) calibration is done to properly adjust the length of the antenna and to monitor the quality of the coaxial cable and all connections. This calibration or "tuning" is to get the best performance from your radio .

While holding mic button adjust the SWR/CAL knob so that the meter needle swings to the “CAL” mark on the meter. While still holding down the mic button, set the S/RF SWR CAL switch to SWR. When switched to SWR position the meter needle should ideally be as far to the left as possible.
Anything over 3 is not good and you can damage your radios transmitter..

When the switch is on S/RF the meter swings proportionately to strength of incoming signal when receiving. Only the squelch knob means squelch.

The RF Gain knob is used to optimize reception in weak signal areas (or bring in weak signals from folks who do not tune their radios). Turn counterclockwise to reduce gain.

The ANL is the Automatic Noise Limiter. This helps reduce noise created by the vehicle’s electronics (usually the alternator ).
NB/ANL means a Noise Blanker is also activated, providing increased noise filtration.
OFF position all noise filtration will be turned off.

DYNA knob is is used for setting the setting Dynamike. This controls the microphone sensitivity (outgoing audio level) and to adjust the PA speaker (if you have one) volume.

A PDF of the manual for that radio is HERE (http://www.cobra.com/downloads/manuals/29WXNWST.pdf)

What if if doesn't go all the way to CAL when I switch it to CAL and hold down the muc button? Its short. And then when I switch it to SWR its over 3. What do I do to lower that?

Turn the knob that says CAL until it does. It's on the far right.

You'll also want to balance out the squelch vs RF gain. I have my squelch set to about 3, and I dial down (or dial up) the RF gain as required. Works for me.

Also, there's a knob on there for MIC GAIN (DYNA). This is your volume control for a PA speaker, but it's also just what it says. If the Mic gain is set too high, you're going to over modulate, which is radio speak for piss people off with an overly loud microphone. It's should really only be used when you're trying to reach someone on the outskirts of the range, just to compensate for the signal degradation and RF noise on the other end.

For night watch, I assume you tried the dimmer knob?

Turn the knob that says CAL until it does. It's on the far right.
i did, the knob is turned as far to the right as it will go, but its still short on the readout.
For night watch, I assume you tried the dimmer knob?
yes i did. the little snake in the corner glows like it should, but nothing else will.

right now i think i need a little more info on shortening or lengthening my antenna, i think that may be part of the problem (plus i dont think its very well grounded, also need tips on grounding it better). After switching the far left knob from CAL to SWR, the readout says over 3. someone earlier said thats bad. what do i do to make the readout go under 3?

3 and over is no good.
I’ll tell you bro I don’t really trust the meters that come in any of the radios even thou they are most likely ok. I have a meter from radioshack (http://www.radioshack.com/product/index.jsp?productId=2036239).
That said check all of your connections and your coaxial cable to make sure they are good. What type of antenna do you have and where is it mounted? How many ft of cable did you use?

You're going to have to adjust the height. When they make the antenna, they can test it all they want in their setup and have it appear to work right. Problem is, once you mount that sucker on your car, in the location you pick, that SWR is going to be off. If it's over 3, then yes, that's no good. That will burn up the RF output in no time. Depending on the antenna you got.. say it's a metal rod on a mount, there should be a set screw of some type you can loosen to adjust the antenna up or down, and then re-tighten the screw. If it's a fiberglass antenna, then you need to trim the top. (Issue there is if for some reason it's too short as is, and you need to make it longer.. well.. not sure on that one lol).

3 and over is no good.
I’ll tell you bro I don’t really trust the meters that come in any of the radios even thou they are most likely ok. I have a meter from radioshack (http://www.radioshack.com/product/index.jsp?productId=2036239).
That said check all of your connections and your coaxial cable to make sure they are good. What type of antenna do you have and where is it mounted? How many ft of cable did you use?

I have a firestik antenna on a firestik door jamb mount. its mounted right above my driver side rear light. if i recall correctly its 9 ft. i could be wrong, it may possibly be 18 ft. i bought it a year ago.

You're going to have to adjust the height. When they make the antenna, they can test it all they want in their setup and have it appear to work right. Problem is, once you mount that sucker on your car, in the location you pick, that SWR is going to be off. If it's over 3, then yes, that's no good. That will burn up the RF output in no time. Depending on the antenna you got.. say it's a metal rod on a mount, there should be a set screw of some type you can loosen to adjust the antenna up or down, and then re-tighten the screw. If it's a fiberglass antenna, then you need to trim the top. (Issue there is if for some reason it's too short as is, and you need to make it longer.. well.. not sure on that one lol).

the RF output is...? its a fiberglass. according to this page rattfink so kindly found for me, you cut one at 1/4" incraments until it works. im looking for 1.5 right? and to make one longer, it says you can add a spring or a disconnect. i already have a spring but i want to keep it so my antenna will move when hit, so i'll start cutting soon probably.

its still entirely possible the mount is not well grounded. i might run a 12ga wire to a good ground i know i can trust (and if all else fails, straight to the battery from my mount itself.)

if the RF output is burnt out, what will i do? before i came here to ask my questions, i'd randomly turn on my radio and call out radio checks to see if anyone responded. if its out, how can i know?

the RF output circuitry. The RF output amp, whatever you want to call it. It will cause that to overheat and burn out. At that point, you have no transmit at all.

I had shown this to someone else with an old CB I had. To speed the demo up, I just took a piece of coat hanger and stuck it in the center pin. I key'ed the mic, and in about 5-10 seconds that wire was really really warm to the touch. You could just imagine how hard that is to the circuit inside the CB.

You can think of it the same way as taking a 2 channel audio amp that can be bridge at 4 ohms, and running a 1 ohm load on it. The current draw on the internal circuits is way more than it was designed for, causing it to heat up and burn out the output stage over time.

(I don't have any better examples right now)

Your Firestick should be tunable. If you take off the red cap on the top of the antenna there should be a screw with a lock nut. You move the screw in and out to adjust the SWR and then lock it with the lock nut.
Most antennas the mount must be grounded. Check that.
You need 18feet of good coax.

Find answers to all questions HERE (http://www.firestik.com/Tech_Docs.htm).

already took the tip off, its a KW, not an FS, so it has no metal rod on top (like my bro in law's)

Ok, another "it's stupid but just make sure..." point.

Make sure the switch that says "CB/WX" is set to CB. On WX, it won't transmit no matter what you do to your antenna :)

Also make sure the RF and Mic gain is somewhere in the middle.

problem is definitely the mount not grounded. unless i've bought two bad antennas. I had a 3' wilson silverload that had the same problem my 3' firestik is having now. i dragged my dad's old magnet mount antenna out of the shed and now my radio is working flawlessly.

The other issue may be the length of the antenna and how close it is to the chassis of the vehicle. That will affect SWR too

You also have to consider the antenna mounting location you chose. When you put the antenna behind the truck (as opposed to on top of it or mounted higher on a tire carrier) a lot of the signal will be blocked by the truck itself.

Magnet mount antennas create a good ground plane. Remember that "ground" when we talk about antennas isn't an electrical ground. It's a plane for static diffusion.

You can purchase a "ground plane" at most truck stops that will create a better ground, although it may not serve your purpose if there's not enough room between the antenna and the body.

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