HP 8560A, Service Manual

Page: 300 / 450

Caution
If a dc block is not used, damage to the HP results. The
HP and many other spectrum analyzers have dc-coupled inputs and
cannot tolerate dc voltages on their inputs.
6. Set the HP to single trigger and press TRACE A
[
CLEAR
-
WRITE
].
Trigger a sweep
of the HP and the signal generator simultaneously. The HP shows the
of the 4.8 IF filters. The 3 bandwidth of the filters should be 1.2
The of the filters should be flat within 2 over 800 Hz.
7. If continuing to the next procedure, “4.8 and 10.7 MHz IF Filters,” press TRACE A
(VIEW) on the HP
8. Reconnect W27 (coax 3) to
4.8 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
2. Fine tune the frequency of the signal generator to center the signal on the screen. Set the
signal generator to sweep one 2 span about this center frequency. Set the spectrum
analyzer to single sweep.
3. Set the HP to 4.8 center frequency and 2 span.
4. Connect the VIDEO OUTPUT ( rear panel) of the spectrum analyzer through a 20
attenuator and dc block to the input of the HP Set the sweep time of the
HP to 10 seconds.
Caution Damage to the HP results if a dc block is not used. The HP
and many other’spectrum analyzers have dc-coupled inputs and
cannot tolerate dc voltages on their inputs.
5. Set the HP to single trigger and press TRACE B
(
CLEAR
-
WRITE
).
Trigger a sweep
of the HP and the signal generator simultaneously. The HP should
show a 3 bandwidth of approximately 320 Hz.
6. To view the bandwidth of the 10.7 MHz IF filters alone, proceed as follows:
a.
b.
C.
d.
e.
If the peak of the active trace (trace B) is not at the same amplitude as the stored trace
(trace A), adjust the HP
reference level as necessary and repeat step 5.
Press TRACE B on the HP 8566.
On the HP 8566, press The bandwidth of the 10.7 MHz filters is displayed
upside down and may have “wings” toward the sides. These “wings” should be ignored.
Press DISPLAY LINE Adjust the display line such that it is at the
peak of trace B (the dimmer trace). Press The signal disappears from the
screen; it is actually below the bottom of the screen.
On the HP press
[
FREQUENCY SPAN
),
0 1
50 Disconnect the signal from the RF INPUT. Press TRACE A
CLEAR WRITE
,
(SINGLE).
8-18 IF Section