Question about Cobra 29 LTD CB Radio

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I have full power but no white noise as they call it.it wont calibrate either.when useing swr or calibrate switch.

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Turn your RF gain all the way up. There is no need to turn it down. Make sure the squelch is down. Also, some days it's just really quiet out. You can turn the radio on some day and hear nothing. Or you could have a problem with the mic.

As for the calibrating. You do not calibrate the radio. that is for calibrating the meter to read the SWR of the antenna. Here is how to tune our antenna.....

It is important to tune your CB radio antenna to the proper length. The length must exactly match the wavelength of the frequency you transmit on. Or be really really close.

All Cb antenna's have a way to adjust the length of the antenna. If it's a mag mount, the metal whip can be slid in and out of a metal collar. Usually a set screw. If its a fiberglass whip, the way to tune it is on top. It either has a small metal rod with a set screw to adjust the length, or it threads in and out to adjust length.

Either type you have it will need to be adjusted for proper length. Here is how to tune the antenna to lowest SWR.

Some radios have a built in SWR meter. Some do not. If yours doesn't have an SWR meter, then you have to use an external SWR meter. Radio shack carries one, and you can find them cheap on ebay.

If you have a built in SWR meter or external, the procedure is the same:

1. Turn the radio to CH 20.(This is the center of the band.)
2. Switch the meter switch to CAL. (CAL stand for calibrate.
3. Key the radio. (Important. Do not talk while keying the radio.)
4. turn the CAL knob up until the meter hits the CAL mark.
5. Now while still keying the radio flip the meter switch to SWR.

Where the meter falls after that point is you SWR reading. If its above 3, that is real bad. 2 is not gonna kill your radio but its not the greatest. 1.5 and under is a good place to be, but the lower the better.

If your SWR is high, Here is how to find out if your antenna is too long or too short.

1. Turn to CH 1
2. Repeat SWR procedure. You must calibrate every time you do it.
3. Remember the SWR reading.
4. Turn to CH 40.
5. Again repeat SWR procedure.
6. Compare the reading between CH 1 and CH 40.

Now if the SWR is higher on channel 1 then channel 40 your antenna is too short. You must make it longer.

If the SWR is longer on channel 40 then on channel 1, then the antenna is too long, you need to make it shorter.

Make height adjustments about an eight inch at a time, and take reading each time.

once the SWR is significantly lower and the reading on channel 1 and 40 are about the same, you a about matched. At this point turn the radio to the center of the band, channel 20 and take an SWR reading.

You should now have a low SWR reading, 1.5 or under. If you are 1.5 or under, you are good to go.

If you cannot get the SWR to an appropriate level, there may be an antenna problem.

Posted on Nov 17, 2010

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1 Answer

What knobs and switches need to be where on my DX 94 HP galaxy to set swr on my antenna


look of the face of the radio.there should be a dial that says swr / cal / power and rf power. calibrate your radio to the cal make the put it on swr to get your reading.

Mar 04, 2014 | Radio Communications

1 Answer

I just bought a used cobra 200 gtl dx im totally clueless to cbs could u tell me where all the controls and buttons should be



  • Hi, I can help.

  • I have uploaded a pic of the Cobra 200 and labeled each knob/switch with letters to reference.
  1. A) Noise blanker - When this switch is pushed the high pitched noises are canceled leaving a more natural sounding receive. Some like it some don't.
  2. B) High Power - This button adjusts the power output of your radio. Inside the radio the pots are adjusted for a low power setting and a high power setting.
  3. C) Roger Beep - This is a beep heard by the person you are chatting with at the end of your transmission.
  4. D) The 10+ KHz - This button when pushed jumps the frequency up 10 Kilohertz to help you better navigate frequencies.
  5. E) This is where you adjust how you are going to modulate. CW is for continuous wave or Morse Code. Unless you have a key don't worry about this setting. FM is for Frequency Modulation AKA the HAM bands. AM is for Amplitude Modulation. USB and LSB are for Upper Side Band and Lower Side Band respectively.
  6. F) is the band adjustment - Each band (A, B, C, D is a set of frequencies.
  7. G) is a dimmer and the SWR calibrate. To use the dimmer push the dim button in a rapid motion. To use the SWR calibrate side press and hold the dim/calibrate button and using the SWR knob on the right side of the radio (L).
  8. H) SWR/, S/RF - If this button is in the out position then your meter will swing as usual. Push the button in to measure SWR.
  9. I) is the volume and squelch. Volume is what is adjusted to how loud you want your speaker. Squelch you adjust to take out the unnecessary white noise.
  10. J) Mic Gain and RF gain - Mic Gain is how much gain you want to your mic. RF gain is how much of the receive you want to pick up.
  11. K) Is the fine and course adjustment that you clarify your frequencies with.
  12. L) You adjust the echo and the SWR with.
  13. M) is the channel selector.





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  • If you have any comments please feel free to leave them here.
  • Hope this helps and thank you for using FixYa.


Regards, Tony

Sep 17, 2011 | Cobra 200 GTL DX 4-Channels Base CB Radio

1 Answer

Which pots do I use to calibrate swr and rf meters on 29classic to match extral meter?


VR5 tx power meter VR6 antenna warning light
There is not pot for swr cal internally. I guess the cal knob broad range pot or variable resistor. Swr readings after user calibration knob on front of radio, for meter should be close. Obviously not as good as external with larger scale meter. If you can not calibrate meter on face with this knob your radio may have less than 4 watts deadkey.
Just to be on the same page. Understand that SWR is a reading of antenna system condition or tuning of antenna to vehicle mounting location. This is a brief description.

Jul 07, 2011 | Cobra 29 LTD CB Radio

1 Answer

Can not remember what the proper settings are for all the switches on an Uniden Trucker PTC104


I don't have one on my bench, but I found a picture of one online.

By what I see, here is how you need the switches set:

Mic Gain - turned clockwise, depends on how much modulated power you want to put out.

Squelch - turn all the way counter clockwise to open it up. Then turn it clockwise to set it where you want.

RF Gain - Turn all the way clockwise will open it up, then turn back counter clockwise to where you want it set.

SWR Cal - only used when the SWR/Cal switch is put in the Cal position. After you know the SWR of the antenna, you can use it to set the meter (while keying up) to what was read.


Cal/SWR/(can't read the bottom letters on the picture) - set to Cal to calibrate the meter to the SWR of the antenna, set to SWR so that if something happens to the antenna system, it will go high and you know there is a problem, set to the bottom to see the output power and incoming signal power on the meter.

ANL-NB/NB/OFF - set to the top to turn on the Automatic Noise Limiter and Noise Blanker, set to the middle to just turn on the Noise Blanker, and set to the bottom to turn both off.

PA/CB - turn to PA if you have a pa speaker connected to the radio, this will let you talk through the speaker. Turn to CB to talk on the cb radio channels.

CH9/(can't read but probably says NORM) Set to CH9 to lock the radio on the channel 9 emergency channel. Set to the bottom to use the channel selector to choose the channel to monitor or transmit on.

And lasty, but obviously, set the channel selector to chose the channel to monitor or transmit over.


This should help you out completely. If you have anymore questions at all, don't hesitate to contact me at rollincbmods@yahoo.com. I will answer any and all questions I can.

Dean Pitts
Rollin CBs
Mount Vernon, TX

Apr 07, 2011 | Uniden Radio Communications

1 Answer

Im tying tom calibrate my cobr 29 nw ltd with firestik 2 antenas im putting the cal button and keying mic and making the neddle go to the left side of the metter where the number 3 is at because if put on...


I'm not sure I understand exactly what you're doing, but I can tell you how to do
an SWR calibration. You have a three-way switch on the left next to the meter.
From top to bottom they are: s/rf (signal/radio frequency), swr, and cal (calibrate).
Put the switch in the "cal" position. Key the mic and hold it. Turn the SWR calibration
knob one way or the other until it lines up with the triangular mark in the upper
right corner of the meter. Then put the switch in the middle (swr) position and key
the mic again. It will give you a reading on the swr band on the meter. The lower the
better: 1:1 is perfect, 1:2 is OK at best. Any higher (especially over 3:1), and you have a
problem that can't be fixed by tuning. You have a bad antenna, a bad coax or a
mismatched pair of antennae if you're running co-phase.Hope this helps.

Jan 15, 2011 | Cobra Radio Communications

1 Answer

I just took my cobra 29 outta my big truck to put in my pickup. when it was in my truck it worked great i installed a 5 1/2 ft wilson trucker antenna on pickup it has a good ground i ran new rg58au coax....


You seem to have a short or an open circuit . Could be a PL259 connector problem, the ant. is defective and can possibly be a bad ground. Try to add an extra GND. from the ant. base to a central GND. point...This will include the power neg. lead from the radio.
PLS E. Note: If the O/P POwer shown when you key up to check SWR is higher than usual this
will indicate a definate ant. problem................GOOD LUCK and have fun learn'n ! ! !

Dec 07, 2010 | Cobra 29 LTD CB Radio

1 Answer

I just need to know how to use it for conversations and what every turn dial means.


you need to hook this up to an antenna. If you are putting it in a car, you need a mobile antenna, if in a house, you need a base antenna. The antenna needs to be tuned for best SWR or you will damage the radio.

Starting from the left of the radio.

Knob 1. Volume/ squelch. The little knob does the volume of what you hear. Big knob squelches out static noise.
knob 2. Dynamike. This is the volume of your voice transmitted. Its how loud people hear you.
Knob 3. RF gain. This is the receive sensitivity. The higher you turn this, the further you can hear. There is almost no reason for you to have this anywhere but full.
knob 4. Delta Tune. This knob should be in the center. If you encounter some one transmitting off frequency, you can move your receive up and down frequency so you can tune that person in. It does not effect your transmit frequency.
Knob 5. CAL. This is to calibrate the meter for taking an SWR reading off the antenna.

Switches starting form the left.

Switch 1. Meter switch. S/RF - will show on the meter, Your signal going out when transmitting, and the signal coming in while receiving. SWR - will show on the meter, your SWR on that channel after you have calibrated the meter. CAL - This is used to calibrate the meter in conjunction with the CAL knob.

Switch 2. ANL - Automatic noise limiter. - This gets rid of electrical interference noise from the vehicle, or other interference sources. ANL/NB - This is the same as ANL, but with NB "noise blanker" This function blanks louder noises that may make it hard to hear people. It's kind of like an automatic squelch, but not nearly as effective as the actual squelch. Also, NB will lessen your receive in that, really low signals will be blanked out.

Switch 3. CB - the radio is in CB mode. This is the normal operation mode of the radio. You can transmit and receive as normal. PA "Public Address" - If you hook a PA speaker to the PA jack in the back, you can mount the speaker on the out side of the vehicle, and talk over it (Its loud). Also, anything you receive over the radio when not holding the mic key, will come over the PA speaker. This is useful when you are not in the vehicle, and need to hear when some one comes on the radio.

Switch 4. BRT and DIM - this is the brightness of the meter light and channel display. BRT stands for bright.

Switch 5. Normal and CH 9, When the switch is in the normal position, everything is normal, but when you flip it up to CH 9 it instantly puts you one channel 9 with out having to turn the dial. CH 9 is the international emergency channel. So it lets you go to Channel 9 quick. when you put it back to normal it will put you on the channel you were on.

Meter explanation. - You have 3 horizontal lines on the meter. the top line is your SWR (only when in SWR mode on the switch. The next one down is you Signal going out. And the bottom one is your signal coming in, in DB's. ***Also noted that part of the SWR line has a CAL )calibration mark. When you have the switch in CAL, and key the mic, you turn the CAL knob up until the needle is at CAL triangle, and then put the radio on SWR and key it. where the needle falls, on the top line is your SWR. If it is in the red your antenna is not tuned, and you can damage your radio.


HERE IS HOW TO TUNE YOUR ANTENN:



It is important to tune your CB radio antenna to the proper length. The length must exactly match the wavelength of the frequency you transmit on. Or be really really close.

All Cb antenna's have a way to adjust the length of the antenna. If it's a mag mount, the metal whip can be slid in and out of a metal collar. Usually a set screw. If its a fiberglass whip, the way to tune it is on top. It either has a small metal rod with a set screw to adjust the length, or it threads in and out to adjust length.

Either type you have it will need to be adjusted for proper length. Here is how to tune the antenna to lowest SWR.

Some radios have a built in SWR meter. Some do not. If yours doesn't have an SWR meter, then you have to use an external SWR meter. Radio shack carries one, and you can find them cheap on ebay.

If you have a built in SWR meter or external, the procedure is the same:

1. Turn the radio to CH 20.(This is the center of the band.)
2. Switch the meter switch to CAL. (CAL stand for calibrate.
3. Key the radio. (Important. Do not talk while keying the radio.)
4. turn the CAL knob up until the meter hits the CAL mark.
5. Now while still keying the radio flip the meter switch to SWR.

Where the meter falls after that point is you SWR reading. If its above 3, that is real bad. 2 is not gonna kill your radio but its not the greatest. 1.5 and under is a good place to be, but the lower the better.

If your SWR is high, Here is how to find out if your antenna is too long or too short.

1. Turn to CH 1
2. Repeat SWR procedure. You must calibrate every time you do it.
3. Remember the SWR reading.
4. Turn to CH 40.
5. Again repeat SWR procedure.
6. Compare the reading between CH 1 and CH 40.

Now if the SWR is higher on channel 1 then channel 40 your antenna is too short. You must make it longer.

If the SWR is longer on channel 40 then on channel 1, then the antenna is too long, you need to make it shorter.

Make height adjustments about an eight inch at a time, and take reading each time.

once the SWR is significantly lower and the reading on channel 1 and 40 are about the same, you a about matched. At this point turn the radio to the center of the band, channel 20 and take an SWR reading.

You should now have a low SWR reading, 1.5 or under. If you are 1.5 or under, you are good to go.

If you cannot get the SWR to an appropriate level, there may be an antenna problem.

Nov 12, 2010 | Cobra 29 LTD CB Radio

1 Answer

How do i calibrate an Aries swr 420 meter for a cb radio


To calibrate the meter set the switch to FWD/CAL/REF and key the microphone without speaking into it. then turn the control until the needle is on CAL. Unkey the mic, set the switch to SWR and then key the mic to read the SWR.

Thanks,
Dodgem250.com

Apr 16, 2010 | Radio Communications

1 Answer

My antenna light stays on even after I have realeased the mike


Try checking the SWR's on channel 1, 20, and 40. The SWR's will change from the low channels to the mid channels to the high channels. The key is to make sure that the SWR's are around 1 or less at all three points. If the light goes out when checking one of them, then the problem is most likely the SWR's. If the light stays on when checking these channels, the issue might still be the SWR's but I would look at the grounding on the antennas. When holding the talk button on the mic and switching from calibrate to swr, can give a false reading. This is due to the calibrate circuit remaining open until you release the talk button. Take the SWR reading by releasing the Talk button on the mic after calibrating then pressing the talk button again after switching back to SWR. This will be the most accurate reading. From everything you described, I would be looking for a grounding problem with the antennas or coax, possibly even a rub though on the coax somewhere in the dash.

Dec 20, 2009 | Cobra 29 WX NW ST 40-Channels Base CB...

1 Answer

John Q president cb


Hi,

If by calibration, you are referring to the check if your antenna is tuned, below information may be of help.
S/RF/SWR/CAL SWITCH. When in the S/RF position, the meter swings
proportionally to the strength of the received signal. When transmitting,
the meter indicates relative RF output power.
When in the "CAL" position, the SWR meter can be calibrated by adjusting
the "SWR CAL" control to the "CAL" mark on the meter face.
When in the "SWR" position, the standing wave ratio is measured.

SWR METER. Measures standing wave ratio of the antenna system.
Used to properly adjust the length of the antenna and to monitor the
quality of the coaxial cable and all RF electrical connections. If there is any
degradation whatsoever in any of the foregoing, due to humidity, salt
spray, vibration or corrosion, the SWR meter reading will rise, thereby
indicating that a problem exists.
To calibrate, switch to the "CAL" position, transmit by pressing the mike
switch, and adjust the SWR control to the "CAL" mark on the meter; then
switch to "SWR" position for the SWR measurement.

If however you are referring to the internal calibration or tuning of the transmit and receive sections, you would need several instruments/equipment such as RF generator (0-30Mhz with 1Khx modulation), Spectrum Analyzer, Modulation Scope, Dummy Loaded Wattmeter, Frequency Meter and some others. These of course are not readily available to the average user.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

Thank you for using FixYa.

Jun 12, 2008 | Cobra 29 LTD CB Radio

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