Agilent Technologies 856290216 Performance Test Failures, If Gain Uncertainty Performance lest

Performance Test Failures

Failures in IF-Section-related performance tests may be investigated using the following information.

IF Gain Uncertainty Performance lest

Failure of this performance test indicates a possible problem with the spectrum analyzer IF gain circuits. Assuming no major IF problems causing IF adjustment errors, IF gain problems in the first 50 dB of IF gain (REF LVLs of 0 dBm to -50 dBm with 10 dB ATTEN) are a result of faults on the A5 IF Assembly. IF gain problems in the next 60 dB of IF gain (REF LVLs of -60 dBm to -110 dBm, 10 dB ATTEN) result from log amplifier faults on the A4 assembly.

A signal level of -5 dBm is required at input (A5J3) for displaying a signal at top screen with 10 dB input attenuation and a 0 dBm reference level.

Isolate IF gain problems on the log amplifier assembly (A4) with the following steps:

I. On the spectrum analyzer, press [PRESET], [SPAN), ZlXRO SPBN , k-1, 1 (GHz), (-1, - 50 dBm.

2.Press ICAL) and IF AD3 OFF.

3.Disconnect cable W27 (coax 3) from A5J5 and connect cable W27 to the output of a signal generator.

4.Set the signal generator controls as follows:

Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i-10 dBm Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.7MHz

5.Simultaneously decrease the signal generator output and the spectrum analyzer REF LVL in 10 dB steps. The signal displayed by the spectrum analyzer should remain at the reference level for each step. If the signal deviates from the reference level, troubleshoot the video offset circuitry on the A4 assembly.

6.Repeat steps 1 through 5 with the spectrum analyzer set to linear.

Scale Fidelity Performance lest

Failure of this performance test indicates a possible problem with the A4 assembly.

w If the Linear, 5 dB/div, or 10 dB/d iv scales are out of specification, the fault is most likely on the log amplifier assembly (P/O A4).

nIf only the 1 dB/div or 2 dB/div scales are out of specification, the fault is most likely on the A3 interface assembly.

9-12 IF Section