HP 8566B Adjustment Manual page 348

22. Analog-To-Digital Converter Adjustments
A N A L O G - T O - D I G I T A L C O N V E R T E R
( B e n e a t h C o v e r )
Location of Analog-lb-Digital Converter Adjustments
Procedure without using Low-Noise DC Supply:
4 .
a. Press (2-22].
b. Key in TRACE A ljZZZ] and SWEEP [w).
C.
Disconnect cable 0 (black) from sweep ramp input A3ASJl.
d.
Short A3ASTP4 to A3ASTP5 or connect SMB snap-on short to
e. Connect DVM to A3ASTPll and ground to A3ASTP4. Set DVM
for V ac.
f. Adjust A3ASR6 OFFS until the level at A3ASTPll is at a
maximum ac voltage as indicated by the DVM (approximately
2.0 V ac). See Figure 3-101 for location of adjustment.
Remove short from A3ASTP4 and A3ASTP5. Reconnect cable 0
(black) to A3ASJl.
h. Press [O-2.5].
i. Connect DVM to A3ASTP5 and ground to A3ASTP4. Set DVM
for V dc.
Press SWEEP Cm]. Note DVM reading at end of the sweep.
The voltage will begin to drift immediately after the sweep
ends. Therefore, the first indication after the sweep ends is the
valid indication. It may be helpful to press Cm) several times
to ensure a valid indication at the end of the sweep.
k. If DVM indication is + 10.020 f0.005 V dc at the end of the
sweep, no further adjustment is necessary. Otherwise, adjust
the sweep is + 10.020 f0.005 V dc.
Figure 3-101.
T P 4 T P 5