3 - 8
BRIEF CHECKING PROCEDURE
3.4
Horizontal section, MAIN TB and DELAYED TIME
BASE.
Preparation:
-
Connect a probe to the CH1 input.
-
Connect the probe tip to the Probe Adjust output socket.
-
Press the AUTOSET key.
-
Adjust the AMPL keys to an input sensitivity of 100mV/div.
-
Adjust the MAIN TB TIME/DIV keys to 100
µ
s/div.
-
Verify that a square-wave as shown in Fig. 3.3 is displayed.
MTB trigger slope:
-
Press the TRIG 1 key and verify that the displayed square-wave starts with a
negative-going signal.
-
Press the TRIG 1 key again and verify that the displayed square-wave starts
with a positive-going slope as indicated in Fig. 3.3.
Time coeficients MAIN TB and VAR in analog mode:
-
Press the left of the MAIN TB TIME/DIV keys and verify that the number of
signal periods increases.
-
Select 500
µ
s/division and verify that one signal period is displayed per division.
-
Press both MAIN TB TIME/DIV keys: this activates the VAR mode. The
message ’VARIABLE TIMEBASE’ is displayed briefly.
-
Press the right of the MAIN TB TIME/DIV keys until 250
µ
s is displayed.
-
Verify that one signal period occupies 2 divisions.
-
Press the left of the MAIN TB TIME/DIV keys until 500
µ
s is displayed.
-
Verify that one signal period occupies 1 divison.
-
Press both MAIN TB TIME/DIV keys: the VAR mode is switched off. The
message ’1-2-5 STEPS’ is displayed briefly.
-
Press the right of the MAIN TB TIME/DIV keys and verify that the number of
signal periods decreases.
-
Select 100
µ
s/division with the MAIN TB TIME/DIV keys and verify that the
square wave is displayed as shown in Fig. 3.3.
MAIN TB and DELAYED TIMEBASE functions:
-
Press the lower CH1 AMPL key so that an input sensitivity of 200 mV/division
is obtained for channel 1.
-
Use the CH1 POS control to position the signal in the upper half of the screen.
-
Press the DTB menu key: the DELAYED TIMEBASE menu appears at the
CRT softkeys.
-
Select DEL’D TB ’on’ and MAIN TB ’on’ from this menu.
-
Use the DELAYED TIMEBASE keys, to select 20.0
µ
s/division.
-
Adjust the DELAY control in the DELAYED TIMEBASE section so that the
display shown in Fig. 3.9 is obtained. For this the TRACK control must be
adjusted so that MAIN TB is above the DEL’D TB display.