Hameg HM1008 Manual Download Page 38

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Subject to change without notice

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:

29.1 ”Time base A only“

The display will be expanded around the screen centre by a
factor of 10, the time/cm adjusted accordingly.

29.2 ”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.

29.3 ”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.

HOR pushbutton

This pushbutton will open the ”Time base“ menu the contents
of which depends on the operating mode selected.

30.1 Analog mode

The following modes are available:

30.1.1

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-SCALE-
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.

30.1.2

This mode implies alternate time base operation. The readout
will show the speeds of both time bases (”A...“ and ”B...“). The
TIME/DIV-SCALE-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

knob, provided its

function was set to ”Delay“, this is the case if the X-POS DELAY

pushbutton 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

C o n t r o l s a n d R e a d o u t

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-MA/REF-ZOOM

pushbutton

which calls the ”Pos./Scale“ menu. Press the function push-
button ”TB B“, this will cause the POSITION 1 knob to act as
the position control for the time base B display. (Trace sepa-
ration.) See also 13.1.4 Y position 2

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

. The magniﬁ er will affect solely

time base B.

30.1.3

”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
(”B..“). The TIME/DIV-SCALE-VAR knob will set the time base
B speed. The 10x magniﬁ er is available by pressing MAG x10

and will expand the display around the screen centre.

30.1.4

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. In this setting a positive slope will trigger.

The (trigger) LEVEL A/B

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.

30.1.5

B trigger –

Edge

Except for the negative edge the function is identical to the one
described above (30.1.4).

VOLTS / DIV

SCALE

VAR

VOLTS / DIV

SCALE

VAR

TIME / DIV

SCALE