Hameg HM504-2, Manual

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15
Subject to change without notice
mode. Whether the LED flashes or is lit constantly depends
on the frequency of the trigger signal.
[11] LEVEL – Control knob.
Turning the LEVEL knob causes a different trigger point
setting (voltage). The trigger unit starts the time base when
the edge of a trigger signal crosses the trigger point. In most
Yt modes the trigger point is displayed in the readout by the
symbol on the left vertical graticule line. If the trigger point
symbol would overwrite other readout information or would
be invisible when being set above or below the screen, the
symbol changes and an arrow indicates in which vertical
direction the trigger point has left the screen.
The trigger point symbol is automatically switched off in
those modes where there is no direct relation between the
trigger signal and the displayed signal. The last setting in
undelayed time base mode is stored and still active if triggered
delay
(“dTr”) time base mode is selected. This allows for a
different level setting for the triggered delay (“dTr”) time
base mode.
[12] X-POS. – Control knob.
This control knob enables an X position shift of the signal(s)
in Yt and XY mode. In combination with X magnification x10
(Yt mode) this function makes it possible to shift any part of
the signal on the screen.
[13] X-MAG. x10 – Pushbutton and LED.
Each time this pushbutton is pressed the x10 LED located
above is switched on or off. If the x10 LED is lit, the signal
display is expanded 10 fold in all time deflection settings >
50ns/div. At 50 ns/div only the expansion is 5 fold and yields
10ns/div. As the X expansion results in a higher time base
speed (lower time deflection coefficient), all time and
frequency relevant information in the readout is switched
over.
After activating X MAG. x10, the visible part of the signal is
that which was previously at the graticule centre. The
interesting part of the signal can be made visible with aid of
the X-POS.
[12] control.
This pushbutton is not operative in XY mode.
[14] VOLTS/DIV. – Control knob for channel I with a double
function.
This control is active only if channel I is enabled and it‘s input
coupling (AC or DC) is activated. Channel I is active in CH I
(Mono), DUAL, Addition (“add”) and XY mode. The knob is
automatically disabled if the channel related to it is switched
off, or if the input coupling is set to GND (ground).
Y-deflection coefficient setting (input attenuator): This function
is available if the VAR. LED is dark.
Turning the control knob clockwise increases the sensitivity
(decreases the deflection coefficient) in a 1-2-5 sequence
and decreases the sensitivity (increases the deflection
coefficient) if turned in the opposite direction (ccw.). The
available range is from 1mV/div up to 20V/div.
The deflection coefficients and additional information
regarding the active channel(s) are displayed in the readout,
e.g.
”Y1: deflection coefficient, input coupling” . The ”:”
symbolizes calibrated measuring conditions and is replaced
by the
”>” symbol in uncalibrated conditions.
VAR.: The vernier (variable) function is described under item
VAR [15].
[15] CH I VAR. – Pushbutton with two functions.
Pressing and holding this pushbutton selects the VOLTS/
DIV. [14] control knob function between attenuator and
vernier (variable). The current setting is displayed by the
VAR-LED located above the knob.
CH I mode:
Briefly pressing the CHI button sets the instrument to channel
I
(Mono CH I) mode. The deflection coefficient displayed in
the readout indicates the current conditions ( ”Y1...” ). If
neither external nor line (mains) triggering was active, the
internal trigger source automatically switches over to channel
I and the READOUT displays “Y1, trigger slope, trigger
coupling”. The last function setting of the
VOLTS/DIV [14]
knob remains unchanged.
All channel I related controls are active if the
input [25] is not
set to GND [26].
VAR.:
After switching the VAR-LED [14] on, the deflection coefficient
is still calibrated. Turning the VOLTS/DIV. [14] control knob
counter clockwise reduces the signal height and the deflection
coefficient becomes uncalibrated.
The readout then displays e.g.
”Y1>...” indicating the
uncalibrated condition instead of ”Y1:...” . Pressing and holding
the CHI pushbutton again switches the LED off, sets the
deflection coefficient into calibrated condition and activates
the attenuator function. The previous vernier setting will not
be stored.
[16] DUAL MENU – Pushbutton with multiple functions.
Switchover on DUAL (two channel), ADDITION and XY
operation:
Briefly pressing selects DUAL mode if channel I (mono) or
channel II (mono) mode had been present before. Then the
deflection coefficients of both channels and the channel
switchover mode (alt or chp) become visible on the READOUT.
The last trigger conditions (source, slope and coupling) remain
unchanged, but can be changed.
Pressing and holding the DUAL pushbutton switches directly
to XY mode if channel I (mono) or channel II (mono) mode had
been present before. On condition XY mode pressing the
pushbutton switches back to DUAL mode.
Choosing the channel switch over or sub menu:
Once DUAL mode is active, briefly pressing the (Dual)
pushbutton opens a Pulldown menu with the current
mode displayed highlighted. The menu offers “chp” (chopped
DUAL), “alt” (alternate DUAL), “add” (Addition) and “XY”
mode.
As long as the Pulldown menu is displayed, briefly pressing
the pushbutton selects the next mode and highlights the
actual setting. Please note “B: Menu Display and Opera-
tion“.
If “add” (Addition) mode is activated, briefly pressing the
pushbutton switches over to DUAL mode, without displaying
the Pulldown menu.
All channel related controls are effective as long as the input
coupling is not set to GND
[26, 29].
DUAL mode:
On the right of the channel II (Y2:...) deflection coefficient the
READOUT displays the channel switch over mode. “alt”
indicates alternate and „chp“, chopped switch over. The
channel switch over is automatically selected by the time
Controls and Readout