Square Wave Operation; Output Amplitude Controls; Incompatible Control Settings; Normoperatingmode - HP 8082A Operating And Service Manual

3 - 6 Any external input pulses must have an ampli-
tude of at least 2OOmV peak-to-peak and must be at least
2ns wide at the level at which
3 - 7
If the SLOPE/POLARITY switch is set to
MAN, the external signal can be simulated by pressing
the MANUAL pushbutton. This button provides a means
of initiating a single pulse (EXT TRIG mode) each time
the button is pressed, a train of pulses (GATE mode)
while the button is pressed, or a pulse whose width is equal
to the time the button is pressed

SQUARE WAVE OPERATION

3 - 9 There is a 8quare Wave facility on the 8082A
which produces a square wave output of 50% duty cycle
in NORMAL mode. If Square Wave is selected in Exter-
nal Trigger or External Width modes, the output is a pulse
shaped version of the trigger input (the output waveforms
are the same as for External Width mode, see Figure
If Square Wave is selected in Gate mode, the output is a
gated square wave, the repetition rate of which is set up
on the pulse period controls.

OUTPUT AMPLITUDE CONTROLS

3-11 Vernier
Because the amplitude vernier is common to
3 - 1 2
both outputs, the amplitude relationship of one output
3-13 ECL Outputs
3 - 1 4 To obtain normal and complement ECL com-
patible pulses from the -two outputs, either one or both
amplitude range switches should be set to the ECL posi-
tion. The ECL levels supplied are -0.9V to -1.7V into
an open circuit, i.e. without an external 50 ohm load.
These output levels can be altered by changing the
of resistors R35 (ECL amplitude) and R60 (ECL-DC off-
set) on board A5 (Amplitude Vernier and DC
board).
3 - 1 5

INCOMPATIBLE CONTROL SETTINGS

When operating the 8082A, the layout of
the Pulse Period, Delay and Width controls helps to avoid
incompatible settings as shown in Figure 3-3. Generally,
the Pulsa Period control should be farthest right but the
controls can all be in a straight vertical line if the Pulse
Period vernier is more clockwise than the other two
triggering is to occur.
PULSE PERIOD
PULSE WIDTH
Figure 3-3. Positioning of Controls
NORM OPERATJNG MODE
3-l 8 In this mode the 8082A requires no external
trigger signal to produce an output.
delay, transition times, amplitude and offset are
justed by the front panel controls.
3 - 1 9 The initial settings (listed below) are given
to obtain a normal pulse waveform (Figure 3-4) for
someone unfamiliar with the operation of the
Both pulse outputs and the trigger output should be
connected to a high-frequency oscilloscope using a
50 ohm system. The oscilloscope (an HP 180C main-
frame with 1810A plug-in or similar 1 GHt bandwidth
sampling oscilloscope) should be set with the sweep
time at O.S&cm and with the sensitivity at 2OOmV/cm.
ULSE switch 3 NORMAL
Mode Switch
TRANSITION TI
LEADING EDGE
TRAILING ED
AMPLITUDE
ON
Mid-range
c c w (24
c w Llqd
0
NORM
Mid-range
Mid-range
1 B-2.0
c c w (1.0)
OFF
NORM