Automatic squelch isnt operating

Your RF gain control needs to be turned all the way up to be able to receive signals and if you are on one of the HF bands like 40 meters or any HF band the squelch control needs to be all the way off! You do not use squelch on HF! When on VHF or UHF then you would rotate the squelch control just to the point that the background noise stops and go no further. Higher squelch settings will only block weak signals and your radio will be deaf! Squelch control rotated just to the point the background noise stops! NO SQUELCH ON HF. Turn the squelch all the way off on HF!

It sounds like you have CTCSS (tone squelch) or DCS (Digital coded squelch) turned on, but the normal squelch setting is set too low. This will stop scanning, and as the radio thinks there is a valid signal, it will not transmit. I have no idea what radio you are using, but this is a common situation with modern radio's.

I suspect you have it in the continuous monitor mode so follow the directions for getting back into the automatic squelch mode.

AUTOMATIC SQUELCH: The FRS is equipped with an automatic squelch circuitry filtering out weak transmission and unwanted noise, usually caused by terrain conditions.

MONITOR:
- This feature turns off the automatic squelch feature, either momentarily or continuously. It helps in receiving signals to its maximum range, but may pick up static signals, too.

Momentary monitor:
- Press the MON button; the monitor symbol will appear.
- Release the button to restore the automatic squelch.

Continuous monitor:
- Press the MON button for more than 2 seconds until a beep sound is heard. The monitor symbol will appear.
- To restore the automatic squelch, press and release the MON button again.

NOTE: You cannot transmit when the Monitor feature is activated.

This comes from the manual I found on-line at:
http://www.michaelknows.com/electronics/walkie-talkie-manual/

Cobra's LTD 29 model Citizen's Band radio features the full 40 channels allowed and a heavy-duty microphone. The radio provides 4 watts of AM radio frequency output with a switchable automatic noise limiter and noise blanker. Other features include Cobra's Delta-Tune function. Making a Cobra LTD 29 hear and receive better involves making changes to the radio's settings, including the settings specific to this brand.
M/F Turn the switch labeled "NB/ANL, ANL, OFF" to the "ANL" position and try the transmission again if noise is affecting reception. "ANL" is an automatic noise limiter function and reduces noise caused by the vehicle's electrical systems and electronics.

M/F Switch to "NB/ANL" to activate the noise blanker, which may also reduce noise if you continue to have problems. It's an RF noise filtration function and will help with ignition noise.

M/F Adjust the "RF Gain" knob by turning it clockwise to increase gain in weak signal areas if you have problems hearing radio traffic.

M/F Set the "Delta-Tune" function to capture a more listenable signal and get rid of adjacent channel noise. Rotate the knob labeled "Deltatune" to the center position for best tuning. Try micro-adjustments to the left or right as well.

M/F Turn the volume up if you still can't hear and as with any CB radio, adjust the squelch if the radio is noisy when there's no traffic. Turn the knob labeled "Squelch" all the way to the left to receive all signals, including noise and turn the control clockwise until the background noise stops. You will be able to hear the strongest transmissions without having to listen to weak signals and noise.
The service manual can be found here

No, the radios should be silent (squelched) when not receiving a transmission. Appliances (computers, televisions, even refrigerators) can generate enough "hash" to break the squelch and give you that "rushing" noise. Make sure that the radios are at least 4 or 5 feet apart, and try moving them to different locations to clear up the problem.

Bill B

What you want to do is tighten up the squelch adjustment and that should reduce the white noise you are hearing. also keep them away from any computers, the square waves generated by them will open up your squelch annoyingly as well.

I have the same walkie talkies and on mine I can hold down the mode/lock button and it will come off of the Rx mode. Also, you should be able to press the talk button and it will come off of the Rx mode.

Hello andy300,

Does the "RX" indicator show on the LCD screen constantly?

This radio does have a monitor function which disables the squelch control, allowing the user to listen to weak signals on the channel. Enabling this function in absence of any signals will cause the user to hear any background static or noise on the channel. You enable this function by pressing Menu + Up at the same time and disable the function by pressing Menu.

I assume that you are familiar with this function from the fact that you mention these keystrokes have no affect on the radio's behavior.

It is possible that the area you are using the radios in / channel you are using them on has a very high noise level. If the noise level is higher then the radio's automatic squelch threshold, then you would hear constant static, hiss, or white noise and the receive ("RX") indicator would show a constant signal. A local noise level can be caused by atmospheric conditions or very busy nearby adjacent-channel radio signals.

Try operating the radios on a different channel and see if that helps. If it is practical, you might try operating the radios in a different local area just to see if that has any effect at all. This would help you determine if the problem was a local one specific to the area you are operating in.

If it is local area related you might consider switching to a different model of radio that includes a Continuous Coded Squelch System (CTCSS) function (called "privacy codes" or "quiet tones" by come manufacturers. This function does not appear to be included in the model you are using and can help keep your radios silent unless you receive a call from another radio using the exact same privacy code.

If the problem persists regardless of channel or area, then you might have a problem with the radio that would require factory service.

Hope this helps. Best regards!
Ken
Go Ahead. Use Us.

Hi,

The RX symbol and static noise would only appear if the squelch is down or if you are receiving something from a transmitter.

Receiving something could mean either an intelligent radio transmission from another comparable unit or this could also be spillover signals from adjacent radio transmitters strong enough to override the squelch settings normally called "splatter". At times, electronic devices could cause this effect such as RFI (radio frequency interference) from units such as a personal computer.

It is also possible that your Monitor Mode is "ON", turning it OFF would possibly resolve the issue To turn OFF monitor mode:Press the vol/mon UP or DOWN key. The RX icon will stop blinking and disappears.

In some cases, a component failure would cause this problem. Your GMR1035-2 uses an Automatic Squelch Feature, this would mean the use of a FM Discriminator Chip for Squelch Control. Most manufacturers uses an MC3357P IC chip for this purpose. This of course would require opening the unit, desoldering the suspected component and solder in a replacement. This would further require that you be familiar with electronic components, circuitry, DVM and a low wattage soldering iron. Should you not be comfortable doing this, perhaps your best bet would be to seek the services of a qualified technician.

Hope this be of some help/idea. Post back how things turned up or should you need additional information.

Good luck and kind regards.