HP 1740A - Page 13

LINE. Switch turns instrument power on
and off.
LINE INDICATOR. Indicator lights when
the instrument power is on.
BEAM FIND. Pressing this pushbutton in-
creases the intensity and compresses the
display within the viewing area.
© BEAM INTENSITY. Controls the brightness
of the CRT display.
6 FOCUS. Adjusts the writing beam for the
o 6 6 @
sharpest trace. Always keep this display
focused to prevent damaging the CRT in-
ternally. :
SCALE ILLUM. Adjust the CRT background
illumination for good contrast between the
background and the graticule.
ALT. Channel A and B signals are displayed
alternately on consecutive sweeps.
Channel A. Displays the channel A input
signal.
Channel B. Displays the channel B input
signal.
A+B. Pressing both channel A @ and chan-
nel B @ displays the algebraic sum of the
channel A and channel B input signals. If
the channel B display is inverted (press
CH B INVT @), an A minus B display
results.
CHOP. Channel A and B signals are dis-
played simultaneously by switching bet-
ween channels at a 250-kHz rate.
TRIG VIEW. Displays the selected internal
or external trigger signal at a fixed sensi-
tivity of approximately 100 mV/div or
1 V/div with EXT = 10@. TRIGGER
LEVEL @ positions the display vertically.
Center screen indicates the trigger thres-
hold level with respect to the trigger signal.
If ALT @ or CHOP @ is selected, three
signals are displayed: channel A, the sel-
ected trigger signal (at center screen), and
channel B.
MAG X5. Magnifies the vertical presenta-
tion five times, and increases the maxi-
mum sensitivity to 1 mV/div. The band-
width is decreased to 40 MHz.
© «oO
BW LIMIT. Reduces the bandwidth of
channel A and channel B to approximately
20 MHz.
CH B INVT. Inverts the polarity of the
channel B signal. In A+B O« 3} mode,
pressing CH B INVT @ results in an A
minus B display.
TRIGGER A. Selects a sample of the chan-
nel A signal as the trigger signal when
INT/EXT @ is in INT.
TRIGGER B. When in INT, a sample of the
channel B signal is selected as the trig-
ger signal.
COMP. When the display mode is set to
channel A, channel B, ALT, or A+B, the
sweep is triggered by the displayed signal.
When in CHOP, the sweep is triggered by
the channel A signal only.
AC. Selects the input coupling and imped-
ance for the vertical amplifiers. In the AC
position the de component of the input
signal is blocked. The lower 3-dB limit
is approximately 10 Hz.
GND. The input signa: is disconnected
from the amplifier, and the amplifier input
is grounded.
DC. All elements of the input signal are
passed to the vertical amplifier. The input
impedance is approximately 1 megohm
shunted by 20 pF.
500. The input signal is dc coupled, and the
input
impedance
is
500.
Pull
the
lever
forward
and
down
to
select
this
position.
Do
not
apply
more
than
5
V
rms
to
the
input connector.
VOLTS/DIV. Selects the vertical deflection
factor in a 1, 2, 5 sequence from 0.005 V/
div to 20 V/div, accurate within 3% with
vernier @ in the CAL position.
Vernier. Provides continuous control of the
deflection factor between calibrated
VOLTS/DIV ranges. Vernier range is at
least 2.5 to 1.
UNCAL. Lights when the vernier control
is out of detent position to indicate
VOLTS/DIV is uncalibrated.
25 a 25)
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car
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Re:
CIN
of
trig
the
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