Hameg HM 2005 Manual Download Page 14

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Subject to change without notice

3. The peak value detection is switched off if the trigger point

can be set outside the maximum peak values of the signal,
thus causing an untriggered signal display.

Slope selection:

Briefly pressing this pushbutton selects which slope of the
signal is used for triggering the time base generator. Each
time this pushbutton is briefly pressed, the slope direction
switches from falling edge to rising edge and vice versa.

The current setting is displayed in the readout under item
“TR: source, SLOPE, coupling”. The last setting in A time
base mode is stored and still active if the alternate (A and B)
or B time base are selected. This allows for a different slope
setting regarding the B time base if the DEL. TRIG. function
is active. The slope direction chosen for the B time base is
indicated in the readout under “DTr: SLOPE, coupling”.

(13)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 (voltage) 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 A time base mode is stored and still active
if alternate (A and B) or B time base mode are selected. This
allows for a different level setting for the B time base if the

DEL. TRIG.

function is active. Under this condition the letter

“B”

is added to the trigger point symbol.

(14)TR

– Trigger indicator LED.

The TR LED is lit in Yt mode if the triggering conditions are
met. Whether the LED flashes or is lit constantly depends
on the frequency of the trigger signal.

(15)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
this function makes it possible to shift any part of the signal
on the screen.

(16) X-MAG. x10

– Pushbutton and LED.

Each time this pushbutton is pressed the x10 LED located
above is switched on or off in Yt (time base) and component
test operation. If the x10 LED is lit, the signal display is
expanded 10 fold in X direction and consequently only a tenth
part of the signal curve is visible. The interesting part of the
signal can be made visible with aid of the

X-POS.

control.

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.

The X magnifier function can be operated in A and B time
base mode. In alternate time base mode (A alternate B), the
X magnification only effects the B time base and similarly
the readout.

Please note that in alternate time base mode the inten-
sified sector may become invisible due to the X position
setting.
This pushbutton is not operative in XY mode.

(17) VOLTS/DIV.

– This control knob for channel I has a double

function.
The following description relates to the input attenuator
function (VAR LED dark). The vernier function is active if the
VAR LED is lit (see

VAR

under item

(18)

Turning the control knob clockwise increases the sensitivity
in a 1-2-5 sequence and decreases it if turned in the opposite
direction (ccw.). The available range is from 1mV/div up to
5V/div. The knob is automatically switched inactive if the
channel related to it is switched off, or if the input coupling is
set to

(ground).

The deflection coefficients and additional information
regarding the active channels 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.

(18) CH I - VAR.

– Pushbutton with several functions.

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...”