Preamp-Motorola

[emberl]

Hello All,

Apologies if i am writing my first post demanding allready for help :

i have some difficulties in finding infos (+Shematics) on this preamp assembled by Motorola.

i have also a link for download other additional pictures and the plan i received when i got the Preamp :

http://www.sendspace.com/file/nzw8ff

I have brought this pice to a technicher and he told me that apperently the plan (that you can visualize in the link above) doesn t seem to be corect because assymetric

if anybody  has any information about this preamp your help would be very appreciated.

Thank you

emberl

 

[newhall]

I think that is part of the Research line police/business band intercom fm radio system. Just posting this on this old thread in case someone finds it and my meager info helps.

 

[nielsk]

Probably easy to trace it out starting from the mic input.
Most likely you will need to replace the electrolytic capacitors, can't hurt to replace the film caps as well as a bad one will likely stop the signal.
Keep in mind this seems to have a power amp in it, if you can find a line level out that is derived before the power amp you can simply leave the power amp tube (s) and associated components out.