HP 3335A - Sweep Mode Control and Indicators; Sweep Mode Operation Controls; HP-IB Status Indicators and Local Control

Section IH
STOP Key. This key is used to stop a single sweep before it
is complete or to halt an auto sweep and return to key-
board control. When pressed the frequency is returned to
the center frequency which was the frequency of operation
prior to activating the sweep mode.
SWEEP OUTPUT: The sweep output provides a dc voltage
from 0 to + 2 V.O V de corresponds to the start frequency
of the sweep and + 2 V the upper limit. During the sweep
the output is proportional to the frequency and can be used
to drive the horizontal axis of a plotter or an oscilloscope.
When the instrument is not in the sweep mode, the SWEEP
OUTPUT is + 1 V dc. When GO TO START FREQ is
pressed, the instrument displays the start frequency of the
sweep and the SWEEP OUTPUT is 0 V. After a single sweep
is complete and the upper limit is displayed, the SWEEP
OUTPUT is + 2 V dc. These points can be used to adjust
the plotter end points.
DISPLAY INDICATORS:
NOTE
In any sweep mode, the frequency display is in
hertz.
CENTER FREQUENCY Indicator. Indicates the front
panel is displaying the center frequency of the sweep. When
the frequency passes through the center frequency during a
sweep, the CENTER annunciator flashes.
SWEEPING Indicator. Indicates the instrument is in the
SWEEP mode. If the instrument is not in an active single
sweep or in auto sweep (i.e., if it is in manual, at start
frequency or at the end of a single sweep), pressing any key
on the keyboard out of the sweep group will take the
instrument out of the sweep mode.
Example:
Program the Synthesizer to sweep a 500 kHz band centered
on 12 500 kHz.
Program the center frequency by programming a frequency
of 12 500 kHz.
Display Result: 12500.0 kHz
Program the sweep width by pressing SWEEP WIDTH, 500,
kHz.
Display Result: 500.0 kHz
Check START FREQ by pressing GO TO START FREQ.
Display Result: 12 250 000.0 Hz SWEEPING annunciator
on.
Initiate a single 10 second sweep by pressing START
SINGLE 10 SEC key.
Display Result: Annunciator above key illuminates, display
shows frequency sweep which stops at 12 750 000.0 Hz.
Sweep time is 10 seconds.
Initiate single 50 second sweep by pressing START
SINGLE 50 SEC key...
3-10
Model 3335A
Display Result: Annunciator above key illuminates, display
shows frequency sweep which stops at 12 750 000.0 Hz.
Sweep time is 50 seconds.
Initiate
an
Auto
Sweep
by
pressing
START
AUTO
key.
Display
Result:
Display
blanks
except
for
SWEEPING
annunciator.
(Instrument
is
continuously
sweeping
from
start
frequency
to
the
upper
limit.)
Stop Auto Sweep by pressing STOP key.
Display Result: Instrument returns to the center fre-
quency.
Display
indicates
12
500.
0
kHz,
SWEEPING
annunciator extinguishes.
Initiate
MANUAL
Sweep
by
pressing
MANUAL
key.
Display
Result:
SWEEPING
annunciator
illuminates
again.
Annunciator
next
to
MANUAL
key
illuminates.
Manually
Sweep
Frequency:
Rotate
frequency
knob.
Display
Result:
Frequency
increases
and
decreases
with
CW
and
CCW
rotation
of
knob.
CENTER
annunciator
flashes
when
sweep
passes
through
12
500.
0
kHz
(the
center
fre-
quency).
Press GO TO START FREQ key.
Display Result: 12 250.0 kHz
Press
MANUAL
key
of
SWEEP
group.
Display
Result:
No
change
in
display.
Rotate
frequency
knob
CW.
Display
Result:
Frequency
increases.
Rotate
frequency
knob
CCW.
Display Result: Frequency decreases until 12 250. 0 kHz
(start frequency) is reached. Further CCW rotation of knob
will not lower the frequency.
NOTE
The same result occurs at the upper limit of the
sweep.
Return the instrument to full keyboard control by pres-
sing the STOP key. This will result in returning to the
center frequency.
NOTE
The single sweep speed of a sweep in progress
can be changed by depressing the other single
sweep key. To go from the single sweep mode
to the auto sweep mode, it is recommended the
STOP key be used to terminate the single sweep
prior to activating the auto sweep mode.
3-54, HP-IB Indicators and LOCAL key.
3-55. The keyboard contains two HP-IB annunciators—
REMOTE and ADDRESSED. One indicates when the
3335A is under remote control; the other indicates when
the 3335A is addressed to listen by the HP-IB controller.