Accuracy (
±
200 kHz deviation, 100 kHz rate): 5%
Maximum Input:
±
1V
SQUARE WAVE MODULATION
The RF output can be pulse modulated via an external modu-
lating signal or an internal square wave generator.
On/Off Ratio:
>50 dB
Rise/Fall Time: <1
µ
s typical
Internal Square Wave Generator: Four square wave sig-
nals (400 Hz, 1 kHz, 7.8125 kHz, and 27.8 kHz), selectable
from modulation menu.
Accuracy:
Same as internal or external 10 MHz time
base.
Square Wave Symmetry:
50%
±
5% at all power levels
External Input: Front or rear-panel BNC, selectable from
modulation menu.
Drive Level:
TTL compatible input
Minimum Pulse Width:
>5
µ
s.
Input Logic:
Positive-true or negative-true, selectable
from modulation menu.
REMOTE OPERATION
All instrument functions, settings, and operating modes (ex-
cept for power on/standby) are controllable using commands
sent from an external computer via the GPIB (IEEE-488
interface bus).
GPIB Address: Selectable from a system menu
IEEE-488 Interface Function Subset:
Source Handshake:
SH1
Acceptor Handshake:
AH1
Talker:
T6
Listener:
L4
Service Request:
SR1
Remote/Local:
RL1
Parallel Poll:
PP1
Device Clear:
DC1
Device Trigger:
DT1
Controller Capability:
C0, C1, C2, C3, C28
Tri-State Driver:
E2
GPIB Status Annunciators: When the instrument is oper-
ating in Remote, the GPIB status annunciators (listed below)
will appear in a window on the front panel LCD.
REMOTE:
Operating on the GPIB (all instrument front
panel keys except for the SYSTEM key and the RETURN
TO LOCAL soft-key will be ignored).
LLO (LOCAL LOCKOUT):
Disables the RETURN TO
LOCAL soft-key. Instrument can be placed in local mode
only via GPIB.
Emulations: The instrument responds to the published
GPIB commands and responses of the WILTRON Models
6600, 6700, and 6XX00-series signal sources. When emu-
lating another signal source, the instrument will be limited to
the capabilities, mnemonics, and parameter resolutions of
the emulated instrument.
GENERAL
Stored Setups: Stores front panel settings and nine addi-
tional front-panel setups in a non-volatile RAM. A system
menu allows saving and recalling of instrument setups.
Whenever the instrument is turned on, control settings come
on at the same functions and values existing when the instru-
ment was turned off.
Memory Sequencing Input: Accepts a TTL low-level sig-
nal to sequence through nine stored setups. AUX I/O con-
nector, rear panel.
Self-Test: Instrument self-test is performed when Selftest
soft-key is selected. If an error is detected, an error message
is displayed in a window on the LCD identifying the probable
cause and remedy.
Secure Mode: Disables all frequency, power level, and
modulation state displays. Stored setups saved in secure
mode remain secured when recalled. Mode selectable from
a system menu and via GPIB.
Parameter Entry: Instrument-controlled parameters can be
entered in three ways—keypad, rotary data knob, or the
∧
and
∨
touch pads of the cursor-control key.
The keypad is used to enter new parameter values; the
rotary data knob and the cursor-control key are used to
edit existing parameter values. The < and > touch pads of
the cursor-control key move the cursor left and right one
digit under the open parameter. The rotary data knob or
the
∧
and
∨
touch pads will increment or decrement the
digit position over the cursor.
Controlled parameters are frequency, power level, sweep
time, dwell time, and number of steps.
Keypad entries are terminated by pressing the appropriate
unit key (GHz/Sec/dBm, MHz/ms/dB, kHz/
µ
s/STEPS, or
Hz/ns/ADRS). Edits are terminated by exiting the edit
menu.
Reset: Returns all instrument parameters to predefined de-
fault states or values. Any pending GPIB I/O is aborted.
Selectable from the system menu.
Master/Slave Operation: Allows two 68XXXB output sig-
nals to be swept with a user-selected frequency offset. One
68XXXB synthesizer controls the other via AUX I/O and SE-
RIAL I/O connections. Requires a Master/Slave Interface Ca-
ble Set (Part No. ND36329).
User Level Flatness Correction: Allows user to calibrate
out path loss due to external switching and cables via entered
power table from a GPIB power meter or calculated data.
When user level correction is activated, entered power levels
are delivered at the point where calibration was performed.
Supported power meters are Anritsu ML4803A and HP 437B,
438A, and 70100A. Five user tables are available with up to
801 points/table.
PERFORMANCE
SPECIFICATIONS
B-6
681XXB OM
