Performance Test Failures

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

IF Gain Uncertainty Performance Test

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 faults on the A4 Log Amplifier assembly.

Table 8-4 lists the reference level range available in each band with 0 dB input attenuation. Table 8-5 lists the input required at A5J3 for displaying a signal at top screen with 10 dB input attenuation and a 0 dBm reference level.

Table 8-4. Available Reference Level Range

,:IBand Frequency Range (GHz) Ref. Level Range (dBm)

Table 8-5. Signal Level for Reference Level Display

Baud Frequency Range (GHz) Input at A5J3 (dBm)

(0 dB Input Atten.)

0

0 to 2.9

- 5

 

 

 

Isolate IF gain problems on A4 Log Amplifier assembly with the following steps:

1. On the spectrum analyzer press (PRESET),(SPAN), Z E R O S P A N , ( f r e q u e n c yIGHz),w,1

(AMPLITUDE),soc--dB;;;).

2.Press (CAL), IF ADJ OFF.

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

8-12 IF Section