Hameg HM404-2.02, Руководство пользователя

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Subject to change without notice
18
Controls and Readout
(30) 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.
In XY mode, signals at this input are used for the Y
deflection.
(31) AC / DC - Pushbutton with two functions.
Input coupling:
Briefly pressing this pushbutton switches over from AC
( ~ symbol) to DC (= symbol) input coupling and vice versa.
The setting is displayed in the readout with the deflection
coefficient.
Probe factor:
Pressing and holding the pushbutton 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 must not be activated unless a x10 (10:1)
attenuator probe is used.
(32) GD - INV. - Pushbutton with two functions.
GD:
Each time this pushbutton is pressed briefly, the input is
switched from active to inactive and vice versa. It is
displayed in the readout as an earth (ground) symbol
instead of the deflection coefficient and the
~ (AC) or =
(DC) symbol.
The GD setting disables the input signal, the AC/DC (31)
pushbutton and the VOLTS/DIV (20) knob. In automatic
trigger mode the undeflected trace is visible representing
the 0 Volt trace position.
The ”0 Volt” position is indicated by a ”” symbol in the
readout. Please note Y-POS. II (9) .
INV.:
Pressing and holding this pushbutton switches the
channel II invert function on or off. The invert ”on”
condition is indicated by the readout with a horizontal
bar above
”Y2” (Yt mode). The invert function causes
the signal display of channel II to be inverted by 180°.
( 33) 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. 1M
Ω
II 20pF.
TRIG. EXT:
This BNC socket is the external trigger signal input, if
external triggering is selected. Briefly pressing the TRIG.
(18) pushbutton, until the TRIG. ”EXT” -LED (18) is lit,
switches the external trigger input active.
The trigger coupling depends on the TRIG. MODE (21)
setting.
Z- Input:
If neither COMPONENT TEST nor external trigger
coupling (TRIG. EXT.) is chosen, the socket is operative
as a Z (trace intensity modulation) input.
High TTL level (positive logic) effects blanking, low level
gives unblanking. No higher voltages than +5 Volt are
permitted.
Below the CRT there are the controls for the readout,
the component tester and the squarewave calibrator
with their outputs.
Please note:
The following description of the cursor related controls
assumes that the readout is visible and the component
tester is switched off.
(34) MENU – Pushbutton
Pressing and holding the pushbutton activates the display
of the
MAIN MENU . It contains the submenus SETUP
and CALIBRATE .
Once a menu is displayed, the following pushbuttons are
of importance:
1. SAVE and RECALL (7) pushbutton.
Briefly pressing selects the submenu or an item within
the submenu.
2. SAVE (7) pushbutton SET function.
Pressing and holding the SAVE (7) pushbutton calls (sets)
the menu or the previously selected item. In those cases
where the item is marked with
ON / OFF the setting
changes from ON to OFF or vice versa.
If “PRESS SECURITY KEY!” is displayed, this function is
available only for HAMEG authorized service workshops.
Press
AUTOSET (3) to switch back to the menu.
3. AUTOSET (3) pushbutton.
Each time the AUTOSET pushbutton is pressed the menu
is switched back one step until MAIN MENU is displayed.
Then pressing the AUTOSET pushbutton again switches
the menu operation off and AUTOSET is set to the normal
function.
(35) ON/OFF - CHI/II - 1/
∆∆∆∆∆
t
This pushbutton has several functions.
ON/OFF:
Pressing and holding the pushbutton switches both cursor
lines on or off. As the cursor lines are part of the readout,
they are visible only if the readout is switched on. If the
cursor lines are switched off and MEAN VALUE
ON is
activated (Menu: SETUP > MISCELLANEOUS) the
instrument is prepared for DC Mean Value display. Please