Fluke PM3082 Service Manual page 448

6 - 2 2
4 - Select in the TRIGGER MTB menu level-pp 'off' and 'dc' trigger coupling.
5 - Adjust LEVEL MTB for a correctly triggered display.
6 - Set the MTB to 5 us.
7 - Select the MTB VARiable mode by pressing both MTB keys at a time: the readout changes into
5.00 us.
8 - Press the 'ns' key and adjust the readout to 2.50 ps.
Requirements:
Verify that the horizontal distance between the time markers equals 2 divisions. Use the X POS
control to align the marker pulses with the graticule. Now check (across the central 8 divisions) if the
timebase accuracy is + 2.8%: make use of the deflection error readout of the time marker generator
to check this.
6.3.26 Time cursor accuracy (continuation of 6.3.25)
This test verifies the accuracy of the time cursors.
Settings/procedure:
1 - Switch the MTB VARiable mode off by pressing both MTB TIME/DIV keys at a time: the readout
changes to 2 ps.
2 - Select 5 ps/div for the MTB.
3 - Switch the deflection error facility of the time marker generator to off.
4 - Press the CURSORS menukey.
5 - Select 'on' and time cursors (//) in the CURSORS menu.
6 - Select A T in the READOUT menu.
Requirements:
Position one cursor line exactly on the 2nd time marker on the screen and the other cursor on
the 10th time marker. The distance between both cursors is 8 time marker intervals then. Check
for a cursor readout between 39.5 and 40.5 ps.
6.3.27 Horizontal deflection; delayed time-base deflection coefficients
The deflection coefficients of the delayed timebase generator (DTB) are verified by means of a
calibration signal.
test equipment:
Fluke 5500A mode: (Alternative: time marker generator TG 501)
test set-up:
5500A
SCOPE
OUTPUT
o
T
OSCILLOSCOPE UNDER TEST
CH1
< Q O O O
V
U
S 0 C 1
CABLE
PERFORMANCE TEST
\
CH2 CH3 CH4
)
ET
50C3 TERM.
STB109