Cobra 29 LTD CB Radio Logo

Related Topics:

A
Anonymous Posted on Jan 28, 2014

Cant adjust swr on cobra 29 with swing kit - Cobra 29 LTD CB Radio

1 Answer

Mike Charette

Level 3:

An expert who has achieved level 3 by getting 1000 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Genius:

An expert who has answered 1,000 questions.

  • Cobra Master 1,847 Answers
  • Posted on Sep 01, 2014
Mike Charette
Cobra Master
Level 3:

An expert who has achieved level 3 by getting 1000 points

All-Star:

An expert that got 10 achievements.

MVP:

An expert that got 5 achievements.

Genius:

An expert who has answered 1,000 questions.

Joined: Sep 24, 2009
Answers
1847
Questions
2
Helped
489669
Points
2211

Make sure you have no noise in the background at all the be my guest. you may have to put a cloth over the mic speaker to keep the noise level down but you can do it.

2 Related Answers

Anonymous

  • 773 Answers
  • Posted on Dec 23, 2009

SOURCE: cobra 29 classic "swing kit" ?

A swing kit is nothing more then a Cap and a resistor. There really isn't a different way to do a swing kit, unless you do variable power, which you don't need unless you are going to run a linear, and even then you can just set the dead key with a swing kit.

you need a watt meter, preferably one that reads peak and average watts. If not, average will be find.

Open the bottom cover of the radio. Hook the radio up to the watt meter, use a dummy load or have it hooked to the antenna. Never key the radio with an antenna or a dummy load.

Find VR4. Its toward the back right of the radio. Turn it all the way to the left. That increases your modulation.

Next find L14. it is at the back in front of the final resistor. While making a steady sound into the radio, just make an ahhhhhhh noise. Back the slug out of the tank until the needle hits peak. Don't move it out any more or you will over bias the final.

Now you will need a 220 uf electrolytic cap, and a 100 ohm 1/2 watt resistor, both of which you can get from radio shack. (this is your swing kit.

To the right of the tank slug is a jumper maked JP36. Us soldering wick to remove the solder and pull out the jumper. Now put the cap in it with the stripe facing the back of the radio.(that is very important. the other way you will blow the radio.) Solder it in place and cut the extra leads off. Now on the back of the board were you soldered in the cap, solder the 100 ohm resistor in between the 2 points.

The amount of resistance determines you dead key. you will be at about a 2 watt dead key which is good for swing and if you want to run a linear. The higher the resistor the lower the dead key, and the lower the cap, the higher the dead key.

That is your basic peak and tune with a swing kit.


Testimonial: "wow ! good info .......thnx"

Ad
anymhz

AnyMHz.com

  • 500 Answers
  • Posted on Jan 03, 2011

SOURCE: swing kit for cobra 29 ltd bluetooth

It wil be the same for any 40 channel cb.. lower the bias and it will give it more swing. we make our own. for a cobra there are only 2 components. unless you want it a variable... and they only cost a few dollars to make. variables are little more because of the transistor and needing a way to control it. if you dont use an existing knob on the radio.

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
2answers

Will a mosfet 520 swing kit give me mor watage to my cobra 29 lx 29 lx

yes , but for the amount you get its hardly going to be worth it.this radio has all kinds of limiters in and it won't let you do one thing without doing this other thing first.A small 100 watt kicker will do a better job and nothing to do to the radio except turn the wattage down so its linier friendly.
0helpful
2answers

Can i use a 10 amp power supply run my cobra 29 and 100 watt linear

I will answer the question. Figuring that 10 amps is continuous not peak. 10 amp multiplied by 12.5 it should be good for 125 watts. But you are on the ragged edge. I do agree you should lower dreaded key but you did not ask that question. But a swing kit will solve that. That is amusing SSB and the 80 watt cobra 29 comments.
0helpful
1answer

My ANT light comes on when ever i push the mic button but my SWR isnt that high

The meter will be more accurate and an external meter will be even better. If they show good disregard the ant light it is adjustable. It may have been set to sensitive from factory. These erroneous SWR reading can be the side effects of a PEAK & TUNE if the coils have been spread but that should also show on meter.
SWR meter calibrations
  • Switch (S/RF SWR CAL) to the CAL position.
  • Push and hold mic button
  • While holding mic button adjust the SWR CAL knob so 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 the SWR position, to read the SWR reading. Note: When switched to SWR position the meter needle should ideally be as far to the left as possible. Anything over 3 is not acceptable.

5helpful
1answer

I have a Cobra CB Radio and was wondering if I have it on SRF or SWR or CAL

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 adjust-
ing the "SWR CAL" control to the "CAL" mark on the meter face.
When in the "SWR" position, the standing wave ratio is measured.

You will want to operate on S/RF position.
0helpful
1answer

I have weak talk back signal

Did you tune the antenna??

The antenna needs to be tuned for best SWR.

If the antenna is not the right length, then you will get signal reflecting back into the radio. this is bad and it can damage a radio.

The 29 has a built in SWR meter.

The lower the SWR the better.

Here is how to check the swr.

Turn to ch 20. Put the sf swr cap switch to CAL. Key the radio. With the radio keyed, turn the cal knob up until the meter is all the way to the right on the cal mark. with the radio still keyed, flip the switch to SWR. Where ever the needle falls is your swr reading. The top line is SWR. If it is above 3 this is really bad, and your antenna is no tuned and you are hurting your radio. You need to adjust the antenna length.

Turn to ch 1 and take an SWR reading the way I explained. Then do the same on ch 40. IF the SWR is lower on ch 1 then 40, your antenna is too short, make it longer. The antenna has a way of adjusting it. Usually the whip slides up or down in a colar.

If the swr is higher on ch 40 then 1, it is too long, and you need to make it shorter.

Keep making adjustments until the reading on 1 and 40 get lower, and are about the same.

Then check ch 20 again. It should be low, 1.5 or under. Then you are good to go.

you will find people hear you a lot better, way better then ever.
2helpful
2answers

Cobra 29 ltd classic ant light

Your SWR is probably NOT fine. You need to use an external meter if you have had work done to the radio. Especially if you have had a swing mod done to the radio. When you do this, the dead key of the radio is lower then the calibration knob on the radio can adjust for. It will always come up lower then it actually is.

Your radio might have been fine before the work was done on it because it was putting out very little power. Now you are most likely putting out 50 watts or more. Big jump from 4 watts.

When your raise the power in a radio, you will notice more when the antenna is not properly tuned.

In most cases with a stock CB, even when the antenna is not even near tuned, you will get a reading less then 1.5 anyway.

the more power you put out, the more important it is to have a good match.

But an external SWR meter, and check it. be careful if the ANT light is on.

You might also want to check your coax, connections to it, and your antenna for anything wrong.
1helpful
1answer

Cobra 29 wx st

IF YOU CAN RECIEVE THAT IS A VERY GOOD SIGN THAT YOUR SWR MATCH IS OFF....I DONT KNOW IF YOU MATCHED UP YOUR RADIO WITH YOUR ANT.IF NOT YOU CAN BUY A CHEAP SWR METER @ RADIO SHACK...CHECK THAT YOUR COAX CABLE IS OK TRY TO REPLACE THE COAX......GOOD LUCK
0helpful
2answers

SWR meter will not go to cal line.

vr2 is the transmitt signal potentiometer for the meter adjustment during keyup try turning it while keying but use something nonconductive to do so or you could short it..be carefull
18helpful
3answers

Cobra 29 ltd classic antenna calibration ??

You should not calibrate the antenna before you install it on the car!! the antenna needs to be calibrated on the vehicle that it is going to be on. Type of vehicle, different mounts, and many other variables can change the amount of reflection you will get.

j0hn9999 did a much better job but left some info out.

Take your SWR readings on channel 1, then on channel 40.... NOW, if your SWR is higher on ch 40 then ch 1, then your antenna is too long and it needs to be shortened. Refer to the antenna instructions on how to shorten the antenna.

If your SWR is higher on ch 1 then on ch 40 then your antenna is too short. You must lengthen the antenna. Again refer to your antenna instructions on how to lengthen your antenna.

You must calibrate each time you take a reading.

Make sure your doors and windows are shut when taking a reading

Make sure you are in an open lot when taking a reading as buildings, trees and other structures can cause reflection and give you an inaccurate reading.

If you adjust the length of your antenna on another vehicle and then put it on yours, the SWR will be off. It will need to be tuned again.

An external meter is better then the one in the radio, but will need to be hooked up in the vehicle you have the antenna on.

If you are not running any kind of power, or do not have a swing kit installed, and the radio is stock, the meter in the radio is more then enough to get a correct SWR reading.
Not finding what you are looking for?

202 views

Ask a Question

Usually answered in minutes!

Top Cobra Radio Communications Experts

Brad Brown

Level 3 Expert

19187 Answers

Mike Cairns
Mike Cairns

Level 3 Expert

3054 Answers

eradiostore
eradiostore

Level 3 Expert

1672 Answers

Are you a Cobra Radio Communication Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...