Fluke CombiScope PM3370B User Manual page 110

HOW TO USE THE INSTRUMENT
DELAYED TIMEBASE
The traces displayed by the Main Timebase and Delayed Timebase can be
separated with TRACE SEP.
If the DELAYED TIMEBASE menu is activated, you will see the
to the TRACE SEP text. The
adjust the trace separation.
- Turn the TRACK control and observe that the DTB trace shifts.
DELAYED TIMEBASE
Using the Delayed Timebase (Del'd) to select, capture, and display a small portion
of the Main Timebase display results in a magnification of the intensified part.
Depending on the ratio between the MainTB and Del'dTB settings, this
magnification can be very significant.
If the input signal contains jitter or any other form of timing instability, this jitter will
be magnified in the same ratio. This can be so much, that the display becomes
unusable. To address such a problem, the Delayed Timebase (Del'dTB) can be
made to trigger on the input signal after the delay time has passed.
Start with the STANDARD SETUP.
- Connect the Probe Adjust signal to the
Channel 1 input.
- Simultaneously press the STATUS and
TEXT OFF keys.
- Switch channel 1 to AC coupling (
- Shift the trace to the upper half of the screen.
- Press the Delayed Timebase (DTB) key to
enter the DELAYED TIMEBASE menu.
- Turn on the Delayed Timebase.
indicates that the TRACK control can be used to
T
TRACK
).
T
dtb
1-
CH1 500mV
4 - 65
TRACE SEP
symbol next
ST6728
TRIGGER
DELAYED
TIME BASE
DEL'D TB
on off
MAIN TB
on off
starts
trig'd
TRACE
SEP
T
LEVEL
0V
ac dc
lf-rej
hf-rej
MTB 1ms ch1
DTB 0.1ms >4.300ms ch1
ST6717