REAR PANEL
CONNECTORS
DWELL
IN
IN
10 MHz
REF OUT
EXT
ALC
IN
FM
IN
AM
IN
PEN
LIFT
OUT
HORIZ
OUT
V/GHz
OUT
SEQ
SYNC
OUT
RETRACE
BLANK
OUT
MARKER
OUT
10 MHz
REF IN
SERIAL
I/O
IEEE-488 GPIB
AUX I/O
CAUTION
DO NOT OPERATE
WITH POWER CORD
UNGROUNDED
FUSE
5A SB
2 REQUIRED
INPUT
115VAC
±
20%
230VAC
±
20%
48-400Hz
1
2
3
4
5
10
6
7
8
9
17
16
15
14
13
12
11
AUX I/O: 25-pin connector that provides for
single cable interface with another sweep gen-
erator (master/slave operation) and with other
WILTRON instruments such as the WILTRON
562 Scalar Network Analyzer. A pinout diagram
for this connector is shown in Figure A-2.
SEQ SYNC OUT: Provides a +5V signal during
sweep retrace, at bandswitching points, and
during each frequency step in step sweep
mode. Also, when video markers are selected,
provides –5V marker pulses and a –10V se-
lected marker pulse during forward sweep.
BNC connector.
HORIZ OUT: Provides a 0V to 10V ramp during
all sweep modes, regardless of sweep width.
In the CW mode, provides a voltage between
0V and 10V proportional to the full frequency
range of the instrument. When the CW Ramp
is enabled, provides a repetitive 0V to 10V
ramp. BNC connector, 50
Ω
impedance.
10 MHz REF IN: Accepts an external 10 MHz
±
100 Hz, 0 to 10 dBm time-base signal. Auto-
matically disconnects the internal high-stability,
time-base option, if installed. BNC connector,
50
Ω
impedance.
10 MHz REF OUT: Provides a 0.5 Vp-p, AC
coupled, 10 MHz signal derived from the inter-
nal frequency standard of the sweep gener-
ator. BNC connector, 50
Ω
impedance.
AM IN: Accepts an external modulating signal
to produce AM on the RF output. AM sensitivity
(linear or log) and input impedance (50
Ω
or
600
Ω
) are selectable via front panel menu or
GPIB. BNC connector.
Figure A-1.
Rear Panel, Series 681XXA Synthesized Sweep Generator (1 of 2)
1
2
3
4
5
6
A-2
681XXA OM
