Nice find on the L3 schematic, PE.
It appears that R9 is a variable resistor for idle current adjustment.
Measuring the voltage drop across R16, 0.22 ohm ballast resistor, will give you your bias voltage.
It appears that R9 is a variable resistor for idle current adjustment.
Measuring the voltage drop across R16, 0.22 ohm ballast resistor, will give you your bias voltage.