HP 37718A Installation And Verification Manual page 112

N OTE
N OTE
Performance Tests
External Mux/Demux
3 Select CHAN 1 on the oscilloscope and set to 1MΩ input impedance.
Load the Telecom Mask
4 On the oscilloscope, use the following key sequence to select and load
the required Telecom Mask:
a/ SHIFT (Blue Key) APPLICATION.
b/
TELECOM MASK/MASK
c/ Use ENTRY/MEASURE control to select DS1_NEW in the
highlighted MSK FILES window.
d/
LOAD SETUP 8 M1M2
Compare Pulse with Mask
5 On the oscilloscope, use the following key sequence to compare the
pulse with the mask:
a/ RECALL 8, (Ensure CH1 Impedance is reset to 1M
TRIGGER,
to ).
Trig'd
b/ DEFINE MEAS
c/ softkey
COMPARE
d/ softkey
TEST ON
e/ softkey
M1M2
f/
AFTER FAIL CONTINUE
g/ RUN
Using the balanced to unbalanced converter reduces the pulse amplitude
by a factor of 1.266. This will cause the comparison with the mask to fail.
To overcome this select CHAN 1 ON and reduce the Volts/Division setting
(highlighted on the softkey display). Reduced Volts/Division = highlighted
value/1.266. The new value can be entered using the keypad
6 The oscilloscope will compare the positive pulse with the mask limits.
A PASS message should appear on the Oscilloscope.
It may be necessary to visibly fit the waveform to the mask by adjusting
the oscilloscope vertical position and horizontal delay to obtain a PASS on
the Mask.
7 Measure the peak pulse amplitude at the mid pulse-width using the
oscilloscope and verify that this is between 1.896V and 2.844V.
3-44
softkey.
softkey.
SETUP and set
PATTERN TRIGGER
softkey
Ω
. Select
softkey