User Level Flatness Correction:
Number of points: 2 to 801 points per table
Number of tables: 5 available
Entry modes: GPIB power meter or computed data
CW POWER SWEEP
Range: Sweeps between any two power levels at a single
CW frequency.
Resolution: 0.01 dB/step (Log) or 0.001 mV (Linear)
Accuracy: Same as CW power accuracy.
Log/Linear Sweep: Power sweep selectable as either log
or linear.Log sweep is in dB; linear sweep is in mV.
Step Size: User-controlled, 0.01 dB (Log) or 0.001 mV
(Linear) to the full power range of the instrument.
Step Dwell Time: Variablefrom 1 ms to 99 seconds. If the
sweep crosses a step attenuator setting, there will be a
sweep dwell of approximately 20 ms to allow setting of the
step attenuator.
SWEEP FREQUENCY/STEP POWER
A power level step occurs after each frequency sweep.
Power level remains constant for the length of time re-
quired to complete each sweep.
MODULATION
AMPLITUDE MODULATION
All amplitude modulation specifications apply at 50%
depth, 1 kHz rate, with RF level set 6 dB below maximum
specified leveled output power, unless otherwise noted.
External AM Input: Log AM or Linear AM input, front or
rear-panel BNC, 50Wor 600Winput impedance. All options
selectable from modulation menu.
AM Sensitivity:
Log AM: Continuously variable from 0 dB/volt to
25 dB/volt
Linear AM: Continuously variable from 0% per volt to
100% per volt
AM Depth (typical): 0-90% linear; 20 dB log
AM Bandwidth (3 dB): DC to 50 kHz minimum
DC to 100 kHz typical
Flatness (DC to 10 kHz rates): ±0.3 dB
Accuracy: ±5%
Distortion: <5% typical
Incidential Phase Modulation
(30% depth, 10 kHz rate): <0.2 radians
Maximum Input: ±1V
FREQUENCY MODULATION
External FM Input: Front or rear panel BNC, 50Wor 600W
input impedance. All options selectable from modulation
menu.
FM Sensitivity: Continuously variable from ±10 kHz per
volt to ±20 MHz per volt (Locked or Unlocked Narrow FM
modes) or ±100 kHz per volt to ±100 MHz per volt (Un-
locked Wide FM mode), selectable from modulation menu.
Maximum FM Deviation:
Locked Mode (1 kHz to 500 kHz rates):
The lesser of ±10 MHz or rate x 300
Unlocked Narrow Mode (DC to 500 kHz rates):
±10 MHz
Unlocked Wide Mode (DC to 100 Hz rates):
±100 MHz
FM Bandwidth (3 dB):
Locked Mode: 1 kHz to 500 kHz
Unlocked Narrow Mode: DC to 500 kHz
Unlocked Wide Mode: DC to 100 Hz
Flatness (10 kHz to 500 kHz rates): ±1dB
Accuracy (100 kHz rate, ±1V input): 10% (5% typical)
Maximum Input: ±1V
SQUARE WAVEMODULATION
The RF output can be pulse modulated via an external
modulating signal or an internal square wave generator.
On/Off Ratio: >50 dB
Rise/Fall Time: <1ms typical
Internal Square Wave Generator: Foursquare 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 ms.
Input Logic: Positive-true or negative-true, selectable
from modulation menu.
B-6 681XXC OMPERFORMANCE
SPECIFICATIONS