I have no sound, even when I key mic. The meter goes up one time and not the next.
This could one or more of the following problems. I'll start with the ones I feel are most likely the cause, but you can check them in which ever order you like.
When the mic is keyed, you should not hear anything from the reciever. The mic's PTT (push to talk) button switches the transciever from recieve mode to transmit mode, if it didn't all you would hear and transmit would be screaching feedback. Also, during the transmit mode, the radio's meter should switch from indicating relative signal strength (or "S" units) to power out where 4 watts AM should indicate full scale deflection of the meter.
This makes me believe that you've got a intermittent connection in the mic circuit. This can be anywhere from inside the mic, mic cord, mic connector and inside the radio - from the mic jack. The cord is supect as it is always being twisted, pulled, stretched and strained under extremes of temperatures and humidity.
You can check the cord by simply replacing it or with a dummy load connected to the antenna, see if keying the mic and shaking the cable makes the power meter jump or bounce. Twist and pull the cord over its entire length - but pay particular attention to the strain relief points near the mic body and connector as these are typical points of failure.
Check contacts inside the mic, between the mic cord and plug, mic plug and mic jack on the radio to be sure there is no oxidation or broken / shorted wires.
There may also be a problem with a blow speaker, which would explain the lack of audio on the reciever. Connect an external speaker to the external speaker jack (if provided) or open the radio to connect a speaker to the one under test.
Least likely - but still possible is a fault with the antenna coax cable, antenna and / or mount. Look for split, crushed, or otherwise damaged cable along the entire length. Pay attention to pinch points, etc. Repair or replace as needed. Look for oxidation build up between the antenna and mounting threads - clean as best you can or replace. Check the coil (if any) on the antenna. Broken, burnt, etc.insulators over coils are indicators of a problems. Again, repair or replace as needed.
I hope this helps you identify the source of the problem - good luck!
Oct 30, 2009 |
Midland 1001Z 40-Channels Base CB Radio