Motorola GM-300 series power output defect.  
   
Your GM-300 mobile or repeater was working fine, then one day it appears to have no output power, or when you measure it you find less than a watt of output.

This is a common problem, a defect in the manufacturing process, and is easily repaired, provided you know what you are doing.

You must completely disassemble the radio to expose the inside of the PA deck.  You must de-solder / remove as much of the old solder as you can from around the main PA transistor.  Make sure you recover the chip capacitors as well.  Once the old solder is removed, re-solder the entire transistor and capacitors with silver solder.

The silver solder provides a much better electrical connection, will not crack nor melt under heated conditions.

Re-assemble the radio, put it on a service monitor, access the service section via the Radio Service Software and perform an alignment on the radio.

It will be back to factory specifications and never have the power drop off problem again.

I am also happy to repair these radios for $65.  You pay shipping both ways.

de  AI4JI

   
   
   
   
   
   
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