Agilent Technologies E8285A Manual page 133

Voltmeter References
When you select the Voltmeter Reference calibration, instructions are displayed
explaining how to measure the negative and positive references with an external
voltmeter. The user is required to key in the readings. If the readings are within
range, the two values are automatically downloaded.
For the Test Set to meet published specifications, the external DC voltmeter must
be ±0.015% accurate when measuring ±5 V. The voltmeter is connected to the test
points on the Measurement board assembly, see
Figure 5-4 Measurement Assembly Test Points
Audio Frequency Generator Gain
The gain of the following paths is calibrated:
• The internal paths that run from Audio Frequency Generators 1 and 2
• The paths that run from Audio Frequency Generators 1 and 2 (individually)
The above-measured levels are used to adjust the output level of the audio
generators so that they produce a calibrated level to the modulation inputs of the
RF generator. These measurements are made at DC. Both positive and negative
levels are measured to produce an optimum calibration factor.
Measurement Board Assembly
(individually) through the Modulation Distribution assembly, to the monitor
select output, then onto Audio Analyzer 1 to the DVM.
through the Modulation Distribution assembly to the AUDIO OUT connector,
externally to the rear-panel MODULATION IN connector, then again through
the Modulation Distribution assembly to the monitor select output and to the
DVM.
Periodic Adjustments/Calibration
Periodic Calibration Menu Descriptions
figure 5-4.
SGND
+REF -REF
a2a33_1.eps
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