Messenger RF Amplifiers
Documentation Project

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These are the Manufacturer's schematics and have so many errors it's hard to list them all. For starters the center tap on the wrong side of the transformers. Also the VCC to the transformers is not correct and the bias circuit is wrong. Anyway use with care. Some day if I get time and can find one to go by I will redraw the schematics.
Model 125 (Class AB)
Model 125 (Class C)
Model 125V (Class C)
Model 250 (Class AB)
Model 250 (Class C)
Model 250V (Class C)
Model 350 (Class AB)
Model 350HD (Class AB)
Model 450 (Class C)
Model 450V (Class C)
Model 500 (Class AB)
Model 500HD (Class AB)
Model M4V (Class AB)


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  Service Information
 Schematic Diagram
Owner's Manual
 Amp Modifications
Picture of the Amp


Copyright © 1998, 1999, 2000, 2001, 2003, 2004

Disclaimer: Although the greatest care has been taken while compiling these documents,

we cannot guarantee that the instructions will work on every radio presented.