Motorola system 500 cb 540 / cb1141

[Copycat32]

Hi all received a Motorola system 500 mobile cb 1141 working great except blown modulation radio is stock/vergin.. Can't and any info on it just want to open up the audio power I'd decent to run on an amp but need to scream at the mic to get close to 80% mod whistle pushing it up to 100%
Any help would be greatly appreciated
Thank You

 

[NZ8N]

What microphone are you trying to use? Motorola 500 series CBs used a preamplified microphone, amplifier in the mic, getting it's power from the radio.

 

[Copycat32]

What microphone are you trying to use? Motorola 500 series CBs used a preamplified microphone, amplifier in the mic, getting it's power from the radio.

Hi using the original preamplified mic with volume band channel switches

 

[nomadradio]

Sure don't remember that one. Several brands had "works in the mike" models with all the front-panel controls on the mike. Just one problem. This makes the mike cord a maintenance nightmare. Takes way more than four wires and the connector will be impossibly obscure. if it breaks, tough luck.

But there's the rub. Mike cords fail more often than the microphone itself. No way to borrow a spare mike and try it. I can't find any tech info online. The only "500" model number I remember was the 555. It was a conventional mobile with a 4-pin Switchcraft mike plug.

If the cord is bad you have your work cut out for you.

73

 

[Copycat32]

Hi my other Motorola has a 4 pin mic connector.. This radio because it has the mic gain channels up and down and channel 9/19 monitor has a 10 pin mic connector. All that is working fine .. Opened nup the radio theres 3 boards old style nothing is marked and all are coated with a clear coat for moisture production..., I'm going to open the mic and see if I get any voltage while keyed up.. Is so I'll mod the mic and put a condenser element inolace of the existing element I believe nits dynamic..
Dont want to golden screwdriver then radio.. Can't find any info /schematics..

 

[TM86]

Thanks to the pic you posted I was able to find the Sam's for it, CB-293. It's in there as the CM540. You may be able to get the info by asking Dan in the "Sam's Photofacts" thread: https://www.worldwidedx.com/threads/sams-photofacts-collection.262787/

You'll need to specify the Sam's number and radio. He's willing to share, but he's not psychic.