On my new Cobra 18 WX STII, I get no noise whatsoever from speaker with the squelch turned either way while NOT connected to an antenna or coax. If I insert the coax PARTIALLY into the SO-239 I can received OK. If I fully push the coax in and tighten then connector, the radio quiets down completely.

Sounds like a antenna issue. Make sure coax is in good order.and antenna is connected properly. You might have to get a "swr" meter to put in line between radio and antenna to make sure antenna is "tuned" to were the radio is operating. Radio shack sells a ok low budget swr/power meter.

some possibilites:
a short in the antenna or the coax feeding it PTT (push to talk) is stuck RF stage of CB burned out due to improperly tuned antenna

check the sw's and the antenna. those are SHORT antennas by cb standards. a 1/4 wave is about 9ft long. a full wave is around 36 ft.. so anything shorter than the 102" whips are prone to have less range. if swr check out. the board on the 18's and 19dx styles need to be resoldered from time to time. simple fix .. don't pay more than $8 to fix the radio...

It is dual watch. you can set it to have two channels monitored. like ch 1 and ch 13 it will flip between those two channels. but if you use say 6, 19, 26 along with another ch it will stay on the channel with the most noise. and you would have to turn up the squelch to compensate.

Its a mic problem. With out a properly functioning mic the radio will not go into receive mode.

Hi, my name is John. Check your antenna that it is getting a good connection,and that it is grounded. Turn your RF GAIN to MAX. Turn squelch all the way to the left. To hear Weather, Press the Weather button. hope this was very helpful.....rate this solution on the four thumbs-up.....John

That's usually a defective amc stage that produces RX audio and TX modulation. It's an integrated circuit that will require a tech fixing it. You will have a transmitted carrier with no modulation, and no sound in your speaker. However, make sure you have a good mike plugged in first, and substitute a known good mike to verify it's not the mike. With the WX band working, the above may not apply.

See if you have a carrier...signal going out, but no modulation. Get your Tech to check the mike wiring/circuitry inside the radio, also.

Take the cover off, flip it over solder side up, check all solder joints for cracks, cold solder joints, check the safety diode where it comes in the radio, before I go further, can you pick up the weather channel?...Does the PA work?...need to check the pre-driver and finals,audio chip, hook up the power meter using a coax three foot jumper from the output from radio to the input of the watt meter, then the antenna, first check the SWR, on the scale on the meter to cal/swr mode,adjust it to spec, then while still keyed down turn the dial to SWR,if it is the safe range your ok,then turn the Dial to 10 or 20 watt scale and key the mic. Does it have any wattage? If not suspect the finals, they are located on the back rail, if it does have RF then its the audio chip, its located on the right side rail facing you,closest to you.remove it and replace it with same ....hope this helps....

Hi and welcome to FixYa,

Initially, pls a couple of ideas you may want to consider/explore or try/check:

• PA/CB switch must be to CB;
• RF Gain max clockwise;
• Squelch counter clockwise;
• Volume to your desired level;
• Mute (off);
• external speaker/speaker connection;
• audio amp, verify if there is TX modulation;
• antenna, antenna cable. SWR should be low.

Good luck and Thank you for using FixYa. Happy New Year.

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have you checked your swr?