How to disable swr alert for northpoint radios

you have no power because your radio is not tuned to your antenna.You get a new radio and put junky coax and a decent antenna and you expect it to work right. Get 75 ft of rg-213 and you will see a change.

In most cases if the mic works the common cause is the transmitter in the mother board is shorting out or not soldered to the board properly. another cause could be that your antenna is too close to the CB and will disrupt the signal.

you might have a final issue and yes you should be able to talk and receive with the amp hooked up
and not under power.If you bought the radio used beware you don't know what the swr reading was on the last owners setup he could of burnd the final and it will affect your receive go get the radio tested cheap solution.

look up the tune mods online for that model i couldnt find them myself but a power mic might be your solution.

what kind of meter? I would go by what is in the radio unless you are using an analyzer.

You may also be getting common mode current. take 6 to 8 inches of coax and make a tight coil about the same size as a spray paint can. Hold it together with electrical tape.

Use the meter in the LX LE to set the SWR then check with the other meter.

Please make sure you are tuning the antenna correctly.



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.






Now: If you have adjusted the antenna properly and you still get the antenna warning light, then the antenna warning circuit may be out of whack. Use an external SWR meter.

You may also be getting common mode current. Its when RF comes down the outside of the coax. If the swr goes up with modulation then it's common mode.

Here is how to stop common mode.

As close to the antenna as you can while still inside the vehicle, take about 6 to 8 inches of the coax, and coil it up into tight even coils and secure into shape with electrical tape.

This is an RF choke, and will stop the common mode current.

If all other radio's are fine and no ant light come one, and are all showing low swr, then turn VR6 back to disable the ant warning light. "only do this if the ant light comes on when SWR is lower then 1.5 and does not swing up with modulation showing that the ant warning light is miss aligned.

The following instructions are for the T289, which is very similar to the T250. It is possible they will work to turn off your beeps.

Alert Tones

The Alert Tones (beeps) on the Talkabout radios are set at a fixed volume

level and cannot be lowered. However, Alert Tones can be disabled. When

Alert Tones are disabled, the radio will receive messages at the volume

setting you've selected, but you will not hear beeps when you press control

buttons.

Disabling Alert Tones:

1. Hold down the Monitor button while you turn radio on.

2. To re-activate Alert Tones, turn the radio off, then on again while holding
the Monitor button down.

Here is a link to the user guide: http://www.motorola.com/mdirect/manuals/T289_User_Manual.pdf

RX/TX light should change to red, however the ANT light is a bad light. This means that your antenna is not adjusted properly. Do not key the radio or talk on it for any other reason then to check the SWR and tune the antenna. If you have the manual that came with your cobra 29, there is a section that explains how to check the SWR. And the manual for the antenna, it will explain how to adjust it.

If not, here is how to do it.........

How to check the SWR on a Cobra 29

Step 1. Find out what your current SWR is on the center of the band.

1. Turn the radio to channel 20.
2. Set the S/RF SWR CAL switch to CAL.
3. Turn the CAL knob all the way counter clockwise.
4. Key the radio. Do not talk into the mic.
5. While holding the mic key, turn the CAL knob to the right until the needle reaches the CAL mark on the top right of the meter.
6. Now flip the S/RF SWR CAL switch to SWR while still holding the key on the mic.

The needle should fall. Where ever the needle is while holding the key is your SWR reading on channel 20. It should be as low as possible. If its a reading of 2, then its not gonna kill the radio but is border line. Any higher and its bad. Using the radio like this will damage the final output transistor. If its less then 2 this is better. You want it to be less then 1.5 or better.

The ANT light may come on with an SWR of 2. running the radio with an SWR of 2 shouldn't hurt the radio, but I don't like to mess around. Get it as low as possible.

How to adjust the antenna for SWR

The length of your antenna will change your SWR. SWR is basically how much RF energy is not leaving the antenna and getting reflected back into the radio. That's why it hurts the radio when its high. An antenna has to be the right length, matching the length of the radio waves in order for it to radiate all of the RF energy out of the antenna.

Most antennas have a way of lengthening or shortening the antenna. If its a mag mount antenna with a metal whip, there is probably a set screw that when loosened, will allow you to raise or lower the whip. If its a fiberglass antenna, under the rubber cap at the top is how you raise or lower the antenna.

Figuring out if your antenna is too long, or too short

Here is how to know weather or not you have to lengthen or shorten your antenna.

1. Take an SWR reading as explained in the first step on channel 1. Write down the SWR for reference.
2. Take another SWR reading on channel 40. Again write it down for reference.

Now if the SWR is higher on channel 1 then on channel 40, its too short. You need to make it longer.

If the SWR is higher on channel 40 then channel 1, then the antenna is too long. You need to shorten it.


Make small adjust ments about an 1/8th to a 1/4th inch at a time. each time checking the difference between channel 1 and 40.

You will know when you are a good match when there is little to no difference between channel 1 and 40's SWR. Once you are satisfied that the difference between 1 and 40 is about the same, and much lower, then turn the radio back to channel 20 and take an SWR reading.

You will now find that the SWR on channel 20 is really low. Most likely under 1.5 or better, Almost nothing on the meter.


Here is a Meter Key, so you know what you are looking at.

Your antenna light alerts you of high S.W.R.

Say your S.W.R. is fine, maybe 1.5:1, and so the antenna light is not on when the amplifier is off.

1.5:1 means 4% reflected power. With just the radio this is less than 1/4 watt. However, turn on the amplifier and 4% is much more and the radio may think the S.W.R. is higher.

That's one option, which may not be a problem. Another possibility is the S.W.R. actually increases which could be from a amplifier which is not true 50 ohms and/or lack of grounding for the increased power level. [email protected] Communications Solutions

After installing the antenna, follow these steps to adjust the
standing wave ratio(SWR).
1. Turn on the CB.
2. Set S/RF/SWR/CAL to CAL.
3. Key the Mic and rotate SWR CAL so the meter points
to CAL.
4. Unkey Mic.
5. Set S/RF/SWR/CAL to SWR.
6. Key Mic again and note the actual measurement on
the SWR scale. Refer to the following table to interpret
the reading.

1:1 - 1.5 Great
1.5 - 2:1 OK
2:1 - 3:1 Not So Good
Higher than 3.1:1 Terrible

The ideal standing wave ratio (SWR) is 1:1, or a meter
reading of 1 on the SWR meter's top scale. A SWR ratio
of 1.5:1 to 2:1 is excellent for most mobile CB antenna
applications.

Check the SWR on Channel 1 and Channel 40
If the SWR is higher on 1, make the antenna longer
If the SWR is higher on 40, make the antenna shorter
Most antenna's are adjustable. Make small adjustments at a time.