31
Subject to change without notice
C o n t r o l s a n d R e a d o u t
(”B..“). The TIME/DIV-VAR knob will set the time base B speed.
The 10x magnifi er is available by pressing MAG x10
25
and will
expand the display around the screen centre.
26.4
B trigger
–
Edge
In this mode time base B will not start immediately after the
delay time set elapsed, but it will be only set ready waiting for a
signal trigger. This has the advantage that any jitter is removed,
but the delay time adjustment will now only have the effect that
the time base B display will jump from signal period to period
if several periods are displayed. In this setting a positive slope
will trigger.
The (trigger) LEVEL A/B
15
knob will set the trigger level for
B. Only normal triggering and DC-coupling are possible. All
parameters of time base A remain stored and preserved. (LE-
VEL, auto or normal, Slope, coupling). In addition to the delay
time (”Dt:...“) also the B trigger parameters are shown in the
readout: ”BTr:slope, DC“. In SEARCH mode the trigger point
symbol will be preceded by ”B“. As mentioned changing the
delay time will not cause a continuous move of the intensifi ed
portion of the time base A display and the time base B display,
but jumps from signal period to period.
If the trigger level symbol of time base B is shifted outside the
signal representation by time base A there will be no triggering
of time base B any more and thus no time base B display. The
same holds in time base B only mode.
26.5
B trigger
–
Edge
Except for the negative edge the function is identical to the one
described above (26.4).
26.6
B trigger – OFF
Time base B will be started upon the end of the delay time set.
The delay time can be changed continuously in this mode which
can be watched on the intensifi ed sector of the time base A
display. The disadvantage here is that with very long delay times
jitter of the time base B display may crop up.
As time base B is not operated in the signal triggered mode the
controls for time base B trigger will be disabled respectively
are only for time base A.
26.7
A variable – On Off
If ”On“ was selected the TIME/DIV-VAR knob
24
will function
as variable control for the time base A speed. Only in time
base A only mode this option will be available in the menu.
For a full description see ”24.3 Variable“.
26.8
B variable – On Off
If ”On“ was selected the TIME/DIV-VAR knob
24
will function
as the time base B variable control. For a full description see
”24.3 Variable“.
26.9
HOLD OFF …%
In this mode the HOLD-OFF time may be selected from 0 to
100 % with the INTENS knob
2
. Values
>
0 extend the waiting
time after a sweep before a new one can start and decrease
thus the repetition rate which may darken the display. This is
indicated by the HOLD OFF-LED
21
lighting up. The HOLD-OFF
time is only valid for time base A.
Further information can be found in the section ”HOLD-OFF
adjustment“ in the chapter ”Triggering and time bases“.
25
MAG x10
(pushbutton)
Pressing this pushbutton will turn on the x 10 magnifi er. No
menu will be shown.
If ”x10“ is illuminated on the MAG pushbutton the magnifi er is
activated. The adjusted time/cm will be shown in the top left
readout.
Depending on the time base mode turning on the magnifi er will
have these effects:
25.1 ”Time base A only“
The display will be expanded around the screen centre by a
factor of 10, the time/cm adjusted accordingly.
25.2 ”Search“ (A and B times bases alternated)
The time base A speed will not be affected. The time base B
speed will be increased by a factor of 10, hence the time base
B display will be expanded 10-fold in X-direction.
25.3 ”B only“:
The time base B speed will be increased by a factor of 10 and
the display hence expanded 10-fold in X-direction.
26
HOR VAR
(pushbutton)
This pushbutton will open the ”Time base“ menu the contents
of which depends on the operating mode selected.
26.1 A only
Only the time base A will be operative. The readout will thus only
show ”A...“ in the top left corner. The TIME/DIV-VAR knob will
set the time base A speed. With the MAG x10 pushbutton the
display may be expanded around the screen centre, increasing
the speed by 10. If the mode is changed from time base A to
”Search“ or ”B only“ all settings of time base A remain intact
including triggering.
26.2
Search
This mode implies alternate time base operation. The readout
will show the speeds of both time bases (”A...“ and ”B...“). The
TIME/DIV-VAR knob will set the time base B speed.
In alternate time base mode part of the time base A display
will be intensifi ed. The horizontal position of the intensifi ed
portion may be shifted using the HORIZONTAL
23
knob,
provided its function was set to DELAY, this is the case if the
X-POS DELAY pushbutton
22
is illuminated. The length of the
intensifi ed sector is determined by the speed of time base
B and is equal to the run time of B. Hence this intensifi ed
portion of A will be spread over the full screen as displayed
by B and thus expanded. The Y-position of the signal is the
same when displayed with either A or B. This means, however,
that both displays will be written over each other. In order to
separate them on the screen for better readability an artifi cial
Y offset may be added to the time base B display. Press the
CH1/2-CURSOR-TRACE SEP pushbutton
11
which calls the
”Pos./Scale“ menu. Press the function pushbutton TB B, this
will cause the POSITION 1 knob to act as the position control
for the time base B display. (Trace separation.) See also 9.1.2
Y-position 2
nd
time base. This function makes sense only in
”Search“ and is unavailable in any other. Also in ”Search“ the
10 x magnifi er is available by pressing the pushbutton MAG x10
25
. The magnifi er will affect solely time base B.
26.3
B only
In this mode only time base B will be displayed, the readout
will thus only show the time base B speed in the top left corner
