Calibration
Drain Voltage Measurement
7
22
Now let's calibrate the JFET transistor by measuring
its drain voltage:
Connect the positive probe of your multimeter to
the drain terminal of the transistor.
Connect the negative probe of your multimeter
to the common ground.
Set the multimeter to the 20V DC range.
Adjust variable resistor R11 until a reading of 11V
is achieved on the voltmeter.
~ Calibration Notes ~
You might find that your
microphone sounds best with a
slightly different reading.
In general, depending on the JFET
IDSS, the drain voltage should be
in the 10.5~11.5V ballpark.
Always calibrate the transistor
with the mic capsule detached.
For a more accurate calibration
procedure, skip to the next page.
