Caution If a dc block is not used, damage to the HP 8566A/B results. The

HP 8566A/B and many other spectrum analyzers have dc-coupled inputs and cannot tolerate dc voltages on their inputs.

6.Set the HP 8566A/B to single trigger and press TRACE A [CLEAR-WRITE].Trigger a sweep of the HP 8566A/B and the signal generator simultaneously. The HP 8566A/B shows the passband of the 4.8 kHz IF filters. The 3 dB bandwidth of the filters should be 1.2 kHz.

The passband of the filters should be flat within 2 dB over 800 Hz.

7.If continuing to the next procedure, “4.8 kHz and 10.7 MHz IF Filters,” press TRACE A (VIEW) on the HP 8566A/B.

8.Reconnect W27 (coax 3) to A4J3.

4.8 kHz and 10.7 MHz IF Filters

1.Connect a 10.7 MHz signal from a signal generator to the input of the A5 IF assembly and decrease the signal generator level to -50 dBm.

2.Fine tune the frequency of the signal generator to center the signal on the screen. Set the signal generator to sweep one 2 kHz span about this center frequency. Set the spectrum analyzer to single sweep.

3.Set the HP 8566A/B to 4.8 kHz center frequency and 2 kHz span.

4.Connect the VIDEO OUTPUT ( rear panel) of the spectrum analyzer through a 20 dB attenuator and dc block to the input of the HP 8566A/B. Set the sweep time of the HP 8566A/B to 10 seconds.

Caution Damage to the HP 8566A/B results if a dc block is not used. The HP 8566A/B and many other’spectrum analyzers have dc-coupled inputs and cannot tolerate dc voltages on their inputs.

5.Set the HP 8566A/B to single trigger and press TRACE B (CLEAR-WRITE).Trigger a sweep of the HP 8566A/B and the signal generator simultaneously. The HP 8566A/B should show a 3 dB bandwidth of approximately 320 Hz.

6.To view the bandwidth of the 10.7 MHz IF filters alone, proceed as follows:

a.If the peak of the active trace (trace B) is not at the same amplitude as the stored trace (trace A), adjust the HP 8566A/B reference level as necessary and repeat step 5.

b.Press TRACE B m on the HP 8566.

C. On the HP 8566, press [A--B)A). The bandwidth of the 10.7 MHz filters is displayed upside down and may have “wings” toward the sides. These “wings” should be ignored.

d. Press (A=), DISPLAY LINE [a’). Adjust the display line such that it is at the peak of trace B (the dimmer trace). Press (B--DL)B]. The signal disappears from the screen; it is actually below the bottom of the screen.

e. On the HP 8566A/B, press [FREQUENCY SPAN), 0 IHz), (j-1, 1 (dB), (-1, 50 m. Disconnect the signal from the RF INPUT. Press TRACE A CLEAR WRITE ,

(SINGLE).

8-18 IF Section