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Table 5-5 .
Hum and Noise Check
FREQUENCY
SWEEP RATE
ADJUSTMENT AND CALIBRATION PROCEDURE .
5-16 .
INTRODUCTION .
5-17 .
The following Adjustment and Calibration Procedures should be used only if
it has been determined through the Performance Checks ,
Paragraph 5-4 through
5-14 ,
that the Model 204C is not performing within its specifications .
5-18 .
If proper performance cannot be achieved with the Adjustment and Calibration
Procedure ,
refer to the Troubleshooting Procedures,
Paragraph 5-26 .
5-19 .
POWER SUPPLY .
5-20 .
Before making any adjustments,
check the power supply voltages at test
points 2 and 3.
They should indicate + 13V and -13V respectively .
If the voltages
have decreased to +11 V and -11V the Model 204C may not meet distortion specifi
cations .
5-21 .
BIAS ADJUSTMENT .
Connect the DC Voltmeter to TP4 ( BIAS) .
Adjust R20 ( BIAS) for OV indication on the meter .
5-22 .
AGC ADJUSTMENT .
a .
Set the Model 204C RANGE switch to X1K and the Dial to 1 .
Connect the DC Voltmeter to TP1 ( AGC) .
5-23 .
AGC AND FREQUENCY ADJUSTMENT.
Leave the DC Voltmeter connected as in Paragraph 5-22 ,
and connect the
Model 204C output to the Frequency Counter .
Set the Model 204C RANGE to
X1K and the Dial to 8 .
5-9
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