HP 70908A, Руководство по обслуживанию

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T est 20. Diagnostics
The purpose of this verication test is to verify proper operation of the internal diagnostic
detectors that trigger the following RF section error codes:
7002 1st LO unleveled
7003 2nd LO unlocked
7004 300 MHz error
7078 Tune Span error
7074 Discriminator unlock
7076 Multiplier unleveled
0043 Problem/Ampl low (reported during the running of system diagnostics)
This is a nal test.
1. Connect the equipment as shown in the test setup illustration for this procedure .
2. Set the mainframe line switch to ON.
3. Load and run T est 20. Diagnostics . Refer to Chapter 2 for information about running the
software .
When performing this verication test, the diagnostic detectors are checked in the following
order:
7002 1st LO unleveled
7076 Multiplier unleveled
The 1st LO unleveled detector monitors the LO leveling amplier drive circuitry . The
multiplier unleveled detector monitors the LO multiplier drive circuit.
These tests use setup #1 (Refer to Figure 8-21), with the microwave source providing
5 dBm at the 1st LO IN. The test rst veries that the detectors are not reporting
errors; the microwave source power then steps down until the detectors do report
unleveled errors . The test fails if the LO unleveled detector does not report before the
multiplier unleveled detector reports .
0043 Problem/Ampl low?
The 0043 error occurs when DUT 21.4 MHz OUT power is too low .
This test prompts for setup #2 connections (Refer to Figure 8-22. Either the full
microwave source or the synthesized source power provides 300 MHz, 010 dBm,
at the DUT RF INPUT . The DUT setup is band 1H0, 10 dB input attenuation. The
calibrated spectrum analyzer measures the DUT 21.4 MHz OUT . The full microwave
source power rst steps down until the detector triggers; the power then steps up
until the detector resets . The acceptable power levels are 012.5 dBm and 7.5 dBm,
respectively , as measured by the calibrated spectrum analyzer .
7004 300 MHz error
The 7004 error occurs when 300 MHz IN power is low or missing.
The synthesized source connects to 300 MHz IN. It rst provides 300 MHz , 08 dBm,
and then 300 MHz , 0 dBm. The detector must rst indicate 300 MHz missing and then
300 MHz present.
Module V erication T ests 8-43