Motorola cm550 audio mod

[Smack32]

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

 

[AudioShockwav]

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

 

[AudioShockwav]

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.

Motorola 555 ssb base tx issue

Got a friend who has multiple of these Motorola 555 base am/ssb and he wanted me to ask, to see if anyone has a known fix for TX dropping out... on Motorola SSB rigs ? Thanks in advance much appriciated, Retro

www.worldwidedx.com

73
Jeff

 

[AudioShockwav]

Sams Photofact CB292 has the service manual for the CM555, which is the mobile version.

See above.

73
Jeff

 

[Smack32]

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

 

[Smack32]

See above.

73
Jeff

Unfortunately I don't have any Sam's..

 

[AudioShockwav]

Ask Dan, first post in the top of this section stuck to the top.

Sams PhotoFacts Collection

I have almost a complete set of Sams PhotoFacts for CB. If anyone needs info on a specific cb radio just like me know and I will see if I have that Volume. KEEP CB ALIVE!

www.worldwidedx.com

73
Jeff

 

[Smack32]

See above.

73
Jeff

Ok the 555 is the base.. 550 mobile same main board minus the power supply .. Thank you ninknow someone that might have that .. I don't have any
Thank You again

 

[AudioShockwav]

Look here.
Link Posted by Brandon in your other thread.

Motorola CM540 no rx

hello friends on this forum, I have a problem with the motorola cm450 cb and I see it's the same as the 555 can't rx and tx, the radio turns on only the noise freq is empty, I'm looking for the schematic but haven't found it, I hope my colleagues here can help solve this problem..thanks in advance..

www.worldwidedx.com

 

[AudioShockwav]

In this thread

Sams PhotoFacts Collection

I think it's a 2950 in there. https://cbradiomagazine.com/ranger-rci-rhf-618-cb-radio-review/

www.worldwidedx.com

That has the alignment instructions.

73
Jeff