Hameg HM 2005 Manual Download Page 16

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Subject to change without notice

The deflection coefficients and additional information
regarding the active channels are displayed in the readout,
e.g. “Y2: deflection coefficient, input coupling”. The

“:”

symbolizes calibrated measuring conditions and is replaced
by the

“>”

symbol in uncalibrated conditions.

(22)CH II - VAR.

– Pushbutton with several functions.

CH II mode:

Briefly pressing the button sets the instrument to channel II
(Mono CH II) mode. The deflection coefficient displayed in
the readout indicates the current conditions (“Y2...). If neither
external nor line (mains) triggering was active, the internal
trigger source automatically switches over to channel II
(

“TR:Y2...

). The last function setting of the

VOLTS/DIV (21)

knob remains unchanged.
All channel related controls are active if the input

(32)

is not

set to

GD (34)

VAR.:

Pressing and holding this pushbutton selects the

VOLTS/

DIV. (21)

control knob function between attenuator and

vernier (variable). The current setting is displayed by the

VAR

LED

located above the knob.

After switching the

VAR-LED (21)

on, the deflection

coefficient is still calibrated. Turning the

VOLTS/DIV. (21)

control knob counter clockwise reduces the signal height
and the deflection coefficient becomes uncalibrated.

The readout then displays

“Y2>...”

indicating the uncalibrated

condition instead of

“Y2:...”

. Pressing and holding the

CHII

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.

The

CHII

pushbutton can also be pressed simultaneously

with the

DUAL (19)

button.

Please note item (19)

(23)TRIG. MODE

– Pushbuttons and indicator LEDs.

Pressing the upper or lower button selects the trigger
coupling. The actual setting is indicated by a LED and by the
readout (“TR: source, slope, AC”).

Each time the lower

TRIG. MODE

pushbutton is pressed the

trigger coupling changes in the sequence:

(DC content suppressed),

(peak value detection inactive),

(high-pass filter cuts off frequencies below
approx. 50 kHz), trigger point symbol switched off

(high frequency noise rejected),

(low-pass filter cuts off frequencies above
approx. 1.5 kHz),

TVL

(TV signal, line pulse triggering)
trigger point symbol switched off,

TVF

(TV signal, frame pulse triggering)
trigger point symbol switched off.

(line/mains triggering) trigger point symbol
and

TRIG. LED (20)

are switched off.

Please note:
In delay trigger mode (B time base) the instrument is
automatically set to normal triggering mode and DC trigger
coupling. Both settings are indicated by the NM- (12) and
the “DC” TRIG. MODE-LED(23). The previous trigger
settings regarding the A time base remain unchanged.

In some trigger modes such as alternate triggering, some trigger
coupling modes are automatically disabled and can not be
selected.

(24) DEL.POS. - HO

– Control knob with a double function and

associated LED. This control knob has two different func-
tions depending on the time base mode.

A time base:

In A time base mode, the control knob applies to the hold off
time setting. If the HO-LED associated with the knob is dark,
the hold off time is set to minimum.
Turning the control knob clockwise switches the LED on and
extends the hold off time until the maximum is reached
(

please note “Hold Off time adjustment”

). The hold off

time is automatically set to minimum (LED dark), if the A
time base setting is changed. The hold off time setting is
stored and active if alternate (A and B) or B time base mode
is selected.

Alternate (A and B) and B time base:

In alternate (A and B) and B time base modes, the knob
controls the delay time setting.

Under alternate time base mode conditions, the delay time
is visible on the A trace, beginning at the trace start and
ending at the start of the intensified sector. In the free run
condition (delay trigger not active) of the time base, an
approximate delay time value is displayed in the readout
(

“

∆∆∆∆∆

t:...”

). This is an aid to find the position of the intensified

sector which may be very small.

If only the B time base is being operated, the delay time can
also be varied, but there is no intensified sector as the A
trace is not visible.

(25) TIME/DIV.

– This control knob has a double function.

The following description applies to the time base switch
function (VAR LED dark).

Time Base Switch:

Turning the control knob clockwise reduces the deflection
coefficient in a 1-2-5 sequence and increases it if turned in
the opposite direction (ccw.). The time coefficient(s) is (are)
displayed in the readout.

In A time base mode, time deflection coefficients between
500ms/div and 20ns/div can be chosen in 1-2-5 sequence, if
the X-MAG. x10 function is not activated.
During alternate (A and B) and B time base operation, the
control knob changes the B time base setting in 1-2-5
sequence. The available deflection coefficient range is from

Controls and Readout

MADE IN GERMANY

A/ALT.

DEL.TRIG

TRS

PUSH
BOTH

PUSH
LONG

VAR.

CH I

CH II

DEL.POS.

ADD