Hameg HM504-2, Manual

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19
Subject to change without notice
The current function is indicated by the VAR LED. The TIME/
DIV. knob functions as a vernier when the VAR LED is
switched on, but the time base setting remains calibrated
until the (vernier) knob is operated. The readout now indicates
e.g.
”>10ms” instead of ”10ms”. Rotating further
anticlockwise increases the time deflection coefficient
(uncalibrated) until the maximum is reached indicated by a
beep. Rotating the knob clockwise has the opposite effect.
Now, the vernier is again in the calibrated position and the
symbol
”>” extinguishes.
Underneath the front panel sector described above, the BNC
sockets and two pushbuttons are located.
[25] INPUT CH I (X) – BNC socket.
This BNC socket is the signal input for channel I. The outer
(ground) connection is galvanically connected to the
instrument ground and consequently to the safety earth
contact of the line/mains plug. The AC/DC/GND pushbutton
[26] is assigned to the input.
In XY mode, signals at this input are used for the X deflection.
[26] AC/DC/GND x1/x10 – Pushbutton with several functions.
AC/DC/GND:
Briefly pressing this pushbutton opens the input coupling
Pulldown menu if a channel mode is present in which
channel I is activated.
The following input couplings are available:
AC , DC and GND
(ground). Please note “B: Menu Display and Operation”.
After the Pulldown menu has extinguished, the READOUT
displays the present input coupling at the bottom right hand
of
”Y1: deflection coefficient” ; the “~“ symbol indicates
AC, the “=” symbol DC and “GND” is for ground.
The
GND setting disables the input signal and the VOLTS/
DIV [14] knob. Then in automatic trigger mode (Yt) the
undeflected trace is visible representing the 0 Volt trace
position; in XY mode the X deflection is deactivated.
x1/x10:
Probe factor selection is performed by pressing and holding
the pushbutton. This selects the indicated deflection
coefficient of channel I displayed in the readout, between 1:1
and 10:1. In condition 10:1, the probe factor is thus indicated
by a probe symbol displayed by the readout in front the
channel information (e.g.
”probe symbol”, Y1... ). In the
case of cursor voltage measurement, the probe factor is
automatically included.
Please note:
The symbol should not be activated unless a x10 (10:1)
attenuator probe is used.
[27] Ground socket 4mm banana socket galvanically connected
to safety earth. This socket can be used as reference poten-
tial connection for
DC and low frequency signal measurement
purposes and in “Component Tester” mode.
[28] INPUT CH II – BNC socket.
This BNC socket is the signal input for channel II. The outer
(ground) connection is galvanically connected to the
instrument ground and consequently to the safety earth
contact of the line/mains plug. The AC/DC/GND pushbutton
(29) is assigned to the input.
In XY mode, signals at this input are used for the Y deflection.
[29] AC/DC/GND x1/x10 – Pushbutton with several functions.
AC/DC/GND:
Briefly pressing this pushbutton opens the input coupling
Pulldown menu if a channel mode is present in which
channel II is activated.
The following input couplings are available: AC , DC and GND
(ground). Please note “B: Menu Display and Operation”.
After the Pulldown menu has extinguished, the READOUT
displays the present input coupling at the bottom right hand
of
”Y2: deflection coefficient” ; the “~“ symbol indicates
AC, the “=” symbol DC and “GND” is for ground.
The GND setting disables the input signal and the VOLTS/
DIV (18) knob. Then in automatic trigger mode (Yt) the
undeflected trace is visible representing the 0 Volt trace
position; in XY mode the Y deflection is deactivated.
x1/x10:
Probe factor selection is performed by pressing and holding
the pushbutton. This selects the indicated deflection
coefficient of channel II displayed in the readout, between
1:1 and 10:1. In condition 10:1 the probe factor is thus
indicated by a probe symbol displayed by the readout in front
the channel information (e.g.
”probe symbol”, Y2... ). In the
case of cursor voltage measurement, the probe factor is
automatically included.
Please note:
The symbol should not be activated unless a x10 (10:1)
attenuator probe is used.
[30] TRIG. EXT. / INPUT (Z) – BNC socket with two functions.
The outer (ground) connection is galvanically connected to
the instrument ground and consequently to the safety earth
contact of the line/mains plug. The input impedance is
approx. 1 MOhm II 20pF.
Briefly pressing the Z ON/OFF VAR
[24] pushbutton switches
over the function of this socket.
TRIG. EXT:
The BNC socket serves as external trigger signal input, if
external triggering is selected.
The trigger coupling depends on the
TRIG. MODE [20]
setting.
Z-Input:
If neither “Component Tester”, delayed time base mode
(“sea”, “del” or “dTr”) nor external trigger coupling (“ext”)
is chosen, the socket is operative as a Z (trace intensity
modulation) input.
High TTL level (positive logic) affects blanking, low level
gives unblanking. No higher voltages than +5 Volt are
permitted.
Below the CRT are the controls for the readout, the component
tester and the squarewave calibrator with their outputs.
[31]
Controls and Readout
INPUT CHI (X)
AC/DC/GND
max.
400Vp
1M
Ω
II
18pF
INPUT CHI (X)
max.
400Vp
1M
Ω
II
18pF
TRIG. EXT.
max.
100Vp
INP.
(Z)
x1 / x10
AC/DC/GND
x1 / x10
CAT I
! ! !
26 27 28 29 30
25