Hameg HM 2005 Manual Download Page 15

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Subject to change without notice

coefficient into calibrated condition and activates the
attenuator function. The previous vernier setting will not be
stored.
The

CHI

pushbutton can also be pressed simultaneously with

the

DUAL(19)

button.

Please note item (19)

(19) DUAL - XY

– Pushbutton with multiple functions.

DUAL mode:

Briefly pressing this button switches over to DUAL mode.
Both deflection coefficients are then displayed. The previous
trigger setting stays as it was, but can be changed.
All controls related to both channels are active, if the inputs

(28)

and

(32)

are not set to

GD (30) (34)

. Whether alternated

or chopped channel switching is present depends on the
actual time base setting, and is displayed in the readout.

ALT

displayed in the readout, indicates alternate channel
switching. After each time base sweep the instrument
internally switches over from channel I to channel II and vice
versa. This channel switching mode is automatically selected
if any time coefficient from 200µs/div to 50ns/div is active.

CHP

indicates chopper mode, whereby the channel switching
occurs constantly between channel I and II during each
sweep. This channel switching mode occurs when any time
base setting between 500ms/div and 500µs/div has been
chosen.
The actual channel switching can be changed to the opposite
mode by briefly pressing both

CHI (18)

and

DUAL (19)

simultaneously. If afterwards the time coefficient is changed,
the channel switching is automatically set to the time
coefficient related mode.

ADD mode:

Addition mode can be selected by briefly pressing the

DUAL

(19)

and

CHII (22)

buttons simultaneously. Whether the

algebraic sum (addition) or the difference (subtraction) of both
input signals is displayed, depends on the phase relationship
and the

INV (30) (34)

setting(s). As a result both signals are

displayed as one signal. For correct measurements the
deflection coefficients for both channels must be equal.

The readout indicates this mode by a “+” sign located
between both channel deflection coefficients. While the
trigger mode is not affected, the trigger point symbol is
switched off. The Y-position of the signal can be influenced
by both

Y-POS

controls

(9)

and

(11)

XY mode:

This mode can be switched on or off by pressing and holding
the

DUAL

button

(19)

mode the deflection coefficients are displayed as

“X...”

for channel I and

“Y...”

for channel II, followed by

“XY”

. Except

the cursor lines which may be active, all other readout
information including the trigger point symbol are switched
off. In addition to all trigger and time base related controls,
the

Y-POS. I (9)

knob and

INV (30)

button are deactivated.

For X position alteration, the

X-POS. (15)

knob can be used.

(20) TRIG. - ALT

– Pushbutton with double function for trigger

source selection and associated LEDs.
The button and the LEDs are deactivated if line (mains)
triggering is selected or XY operation is chosen.

With the aid of this button, the trigger source can be chosen.
There are three trigger sources available: channel I, channel
II (both designated as internal trigger sources) and the

TRIG.

EXT. (35)

input for external triggering.

The availability of the internal sources depends on the actual
channel mode. The actual setting is indicated by the
associated LED(s). Briefly pressing the button switches over
in the following sequence:
I - II - EXT - I in DUAL and ADD (addition) mode,
I - EXT - I

if mono channel I is present,

II - EXT - II

under mono channel II conditions.

Each condition is indicated by the associated LED and
displayed by the readout (

“TR:Y1...”, “TR:Y2...”

and

“TR:EXT...”

). The trigger point symbol is switched off in

external trigger condition.

ALT:

Pressing and holding the button selects alternate triggering
in

DUAL

mode. Under these conditions both I and II LEDs

are lit and the readout displays

“TR:ALT...”

. As alternate

triggering requires alternate channel operation, alternate
channel switching is set automatically. A change of the time
coefficient then has no affect regarding the channel switching
mode. In addition to the deflection coefficients display,

“ALT”

is displayed by the readout instead of

“CHP”

. In alternate

trigger mode the trigger point symbol is switched off.

Alternate triggering

is not available or automatically

switched off under the following conditions:

– ADD

(addition) mode,

– alternate

(A & B) time base mode,

– B

time base mode,

– TVL, TVF

and

line

(mains) trigger coupling.

(21) VOLTS/DIV.

– This control knob for channel II 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

(22)

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
20V/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).

Controls and Readout

MADE IN GERMANY

A/ALT.

DEL.TRIG

TRS

PUSH
BOTH

PUSH
LONG

VAR.

CH I

CH II

DEL.POS.