4 - 34
PERFORMANCE TEST
8
-
Verify that the difference between the start of MAIN TB and the start of the
intensified part is between 0.9 to 1.1 divisions.
9
-
Adjust the delay time to 5.00
µ
s with the DELAY control (in the DELAYED
TIMEBASE section).
10 -
Verify that the difference between the start of MAIN TB and the start of the
intensified part is between 9.9 and 10.1 divisions.
4.3.29
Horizontal deflection; delayed timebase jitter
There is a certain instability in the starting point, the so called jitter, of the
DEL’D TB. The maximum allowed jitter is checked in this test.
Test equipment:
Fluke 5500A mode: levsine (Alternative: function generator PM5136).
Test set-up:
Settings/procedure:
1
-
Apply a 1 MHz sine-wave signal of 120 mV(pp into 50
Ω
) to input CH1.
2
-
Press the AUTOSET key and set for a trace-height of 6 divisions.
3
-
Use a 50
Ω
termination. For instruments with switchable 50
Ω
input
impedance it is recommended to make use of this feature (via
VERT MENU key).
4
-
Press the DTB menu key and select DEL’D TB ’on’ and MAIN TB ’on’ from
the appropriate menu.
5
-
Set MAIN TB to 500
µ
s.
6
-
Set DEL’D TB to 500 ns.
7
-
Adjust the delay time to 0s using the DELAY control (in the DELAYED
TIMEBASE section).
8
-
Switch the MAIN TB display to ’off’ in the DELAYED TIMEBASE menu;
only the DEL’D TB is displayed now.