Model 8642A/B
Operation
RF FREQUENCY SWEEP
Description Two types of frequency sweep are available. Stepped Frequency Sweep sweeps from a
start end-point to a stop end-point in linearly spaced, incremental steps. Phase
Continuous Frequency Sweep (Special Function 123) sweeps from a start end-point to a
stop end-point in a linear, phase continuous manner.
Sweep step size is automatically selected based on the frequency span (which is the
absolute value of the start frequency minus the stop frequency) and the sweep time.
Although step size for the Stepped Frequency Sweep cannot be directly set, this operating
instruction provides ways to calculate a sweep time io enable you to select a particular
step size or number of steps.
Table
3-12
Electrical Characteristics
Digitally Stepped
Frequency Sweep
Range
Time
Phase Continuous
Frequency Sweep
Maximum Sweep Span
Time
X Axis Output
Z Axis Output
RF Frequency Sweep Operating Characteristics
Performance Limits
0.100000
to
1057.500000
MHz
1
0.100000
to
2115.000000
MHz
1
275
ms
minimum
999s maximum
800.000
kHz
(8642B only)
400.000
kHz
200.000
kHz
100.000
kHz
50.000 kHz
2
25.000 kHz
2
12.500 kHz
2
6.250
kHz
2
3.125 kHz
2
25.000 kHz
2
400.000
kHz
5
ms
minimum
999s maximum
Maximum
and
minimum sweep
times
are
also dependent
on
the sweep span
and
carrier
frequency.
0
to 10 Vdc
TTL Positive True
1
In
AUTO sweep mode,
it is not
possible
to set
start
and
stop end-points
if one
with
a
second end-point greater than 132.187500 MHz (band 6). Also,
it is not po
(8642B only).
2
Maximum end-point separation
may be
increased
up to
that shown
for the H
than
the
span shown here.
HET
band
can
also
be
selected with Special Fun<
3
The
HET
Band.
4
Buffer this output
in
order
to use the
Z-axis output with
a
plotter
for pen
lift
Conditions
8642A
8642B
End-points
can be
outside
the
band
but
(Start Frequency
+
Stop Frequency)
-r 2
must
be
within
the
band.
1057.500001
to
2115.000000
MHz
528.750001
to
1057.500000
MHz
264.375001
to
528.750000
MHz
132.187501
to
264.375000
MHz
66.093751
to
132.187500
MHz
33.046876
to
66.093750
MHz
16.523438
to
33.046875
MHz
8.261719
to
16.523437
MHz
4.130860
to
8.261718
MHz
0.100000
to
4.130859
MHz
0.100000
to
132.187500 MHz
3
±10%
For
crt
display blanking
during retrace
4
end-point
is
less than 4.130860 MHz (band
2)
ssible
to set a
sweep across 1057.500000 MHz
ET band
by
selecting
a
frequency span larger
Mion
8.
3-49
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