Radio puts transmits fine, but sometimes will not receive. have a brand new antenna that works fine with other radios. you can hear but the its like the volume goes down as far as you can turn it. any ideas?

Check coax continuity with a VOM/ continuity tester. Make sure the braid and center conductor aren't touching. OR, put the radio on an antenna system that is known to be working and see if receive works. If after these tests you still don't hear anything, You may need to talk to a repair technician.

Sounds like a bad receiver in the radio.
Have you checked the VSWR of you antenna system?
Did it ever work with the current setup?
If so has anything changed with the programming of the radio or the antenna system?
Does 70cm work OK?
Are you sure menu item 080 is set to "SQL" and not "RF-GAIN"?
Are you sure the receiver is not programmed for tone squelch?
Either of those settings could cause receive problems if not used properly.

Contact Motorola Solutions.

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Mark
Motorola Mobility Support

There are any number of reasons for no sound. I will assume you're using new batteries or fully charged batteries. The simplest reason is that a wire has become disconnected from the speaker. This would make the radio sound the same on as off. To test this see if the radio has a way of turning the squelch off, sometimes a simple push button, sometimes a menu setting, sometimes a dial to adjust the squelch setting. If there is no hissing, sometime very loud so turn your volume down first, then either the audio output amp is dead or a wire to the speaker is broken or disconnected. I today's radios the audio amp is most likely a simple small IC but, it could be inside an all-in-one chip and if it's proprietary getting the chip could be a problem. If it's a simple audio chip you'll have to find a replacement or rig up another audio amp IC to work as a replacement. Let's hope for the simple broken or disconnected wire which should be easy enough to fix.

Now, if when you remove the squelch you hear the hissing but you still cannot hear transmitting from your other radio, it could be that the one transmitting is in fact NOT transmitting an not that the other radio cannot hear. You have checked that both radios can or can not hear someone else's radio right?

Assuming you do know that one radio cannot hear what the other can and make no sound other than hissing when the squelch is off the problem is either in the RF or IF sections of the radio's receiver. In general this used to be a more complex repair so let's go another easy fix by going to the very first place the RF comes in, the antenna.

Just like the audio section when a speaker wire is disconnected sometimes the wire or trace going to the bottom of the antenna can become disconnected or broken. To check this bring a good transmitting radio very close to the one that hisses but does not hear the transmitting radio and see if any place as close as you can get the two radios causes the non-hearing radio to hear the transmitting radio. If so, then look for a problem with the antenna connection.

If none of these easy things bring the problem to heel then there's probably something amiss in the RF or IF receiver sections. If the radio has one or two chips that do all the work here then see if you can get both and replace them. I haven't even taken apart my own small FRS radios to see how complex the receivers are in these so I won't go any further than that since I simply don't know your radio.

I hope that helps.

Most problems with radios that receive but do not transmit are antenna or antenna wire/connector issues. It's easy to receive with a marginal antenna but transmitting requires a good working antenna. If you have a SWR meter or can get your hands on one, install it in line with the antenna and test for reflected power. Of course, make sure your TX light comes on when you depress the mic switch. If not, switch mic and try again.
Hope this is helpful! Reply if u can.

if this radio is new, return it. Its garbage. Its the worst CB cobra ever made, and one of the most hated.

Still people should hear you. Have you calibrated your antenna for best SWR?

Look in your manual. Read the section on SWR. The antenna needs to be tuned, or your RF energy is not going out of the antenna, and being reflected back into the radio. That's bad.

And its "Coax" Not co-aux.

the problem could still be with your swr . If your jeep is fiberglass at the point where your antenna connects that could be the problem. move it to a point where there is metal to get a good ground plane and you should hear people talking.

its the coax. i had this same issue. i thought a bought a great strand but, it was very poor in design and it developed many breaks over time, reducing its transmitting ability. I would also check the mic wire and head connections as well. this is a problem spot at times.

ant. light should only come on if you have a high vswr a bad thing did you check that cb/pa switch is set to cb check your swr this is not a good place to mount ant. as it is close to metal of back of cab

You Need to check and set you SWR on the antenna system. You may also have a bad coax or the ant studs ( mounting hardward ) for the antennas may be bad. It definally sounds like an ant/coax problem Good Luck
Ed
NC Electronic
Mills, Wyoming