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Motorola cm550 audio mod

Smack32

New Member
Aug 26, 2023
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Hi all.. I just pickedup a Motorola CM-550 ssb radio
Its in fantastic shape .. Totally virgin ..
I'd like to openup the audio .. It's doing 4 to 5 dead key. But low audio
Can't find any info on this.. Like to set it up for by brother to use..
Can anyone help as to what to do or look for..
Thank You
 

Are you using the standard Motorola Mic?
Its been a while but If i remember right it uses voltage supplied by the radio to power the amp board in the Mic.
I think it is the same board as the CB 555.

73
Jeff
 
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Web search shows a old thread here about the 550.
NZ8N's posts confirm powered Mic and CB 555 board.
Also the Sam's issue number.

73
Jeff
 
Are you using the standard Motorola Mic?
Its been a while but If i remember right it uses voltage supplied by the radio to power the amp board in the Mic.
I think it is the same board as the CB 555.

73
Jeff
Tried the stock Motorola mic and a astatic power mic.. Same issue .. I have 2 550s tried comparing but couldn't finf anything the 550 I had is great sounding had it peaked back in the 80s. The tech is no longer with us that did it.. I'm not familiar with Motorola products ..
Not sure if it's a pot.. Transistor diod resistor that has to be molded. Don't want to ruin anything it's a virgin radio in mint condition . Just want to get the audio opened up.. Give it to my brother with a cs-1 to use as a base
 
Look here.
Link Posted by Brandon in your other thread.


 

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