HP 8642A Operating Manual page 20

Model 8642A/B
General Information
Table 1-2. Supplemental Characteristics (1 of 2)
Supplemental characteristics are typical, but non-warranted performance parameters, intended to be useful in instru­
ment applications.
FREQUENCY
Underrange: 10 to 100 kHz.
Heterodyne Mode (HET, Special Function 8): The 8642A/B
can derive its output through a heterodyne mode in the
carrier frequency range from 0.1 MHz to 132.1875 MHz.
This improves modulation and some frequency sweep
characteristics at lower carrier frequencies.
Frequency Switching Time to Within 100 Hz of Final
Frequency:
Processor Delay
20 ms
Frequency Settling
65 ms
Total Time
85 ms
SPECTRAL PURITY
SSB Phase Noise at 1 GHz Carrier Frequency (dBc in 1 Hz
bandwidth):
10
Hz
- 4 0
100
Hz
- 7 5
1
kHz
- 9 8
10
kHz
-131
20
kHz
-138
100
kHz
-146
200
kHz
-147
1
MHz
-147
10
MHz
-154
Measured SSB Phase Noise at 1 GHz:
0
_ - 2 0
N
5 - 6 0
m
in
6 80
z
3 - 1 0 0
CO
£ -120
m
8 - 1 4 0
-160
10 1(
'
■
-
I "*
|
)0 1k 10k 100k 1M 1 C
Offset Frequency, Hz
M
SSB AM Noise Floor at 200 kHz Offset, +16 dBm:
<—157 dBc/Hz, band 2 through 9.
<-150 dBc/Hz, band 10.
MODULATION
External Input Impedance: 600 ohms, ±10%.
External Input Level Required: 1 Vpeak for specified accu­
racy. Front-panel annunciators indicate application of
1V peak signal ±5%, 20 Hz to 100 kHz. When greater
accuracy is required, modulation drive voltage should
be monitored externally.
Modulation Source Capability: All modulation types can be
driven with either an internal or external modulation
source. AM, FM, and * M can also be driven simultane­
ously by both internal and external modulation sources.
Mixed Modulation Types: Any two modulation types can
be simultaneously selected except for FM + * M and
AM + pulse modulation.
FREQUENCY MODULATION
Carrier Stability in FM Mode:
AC FM: Same as CW.
DC FM: <4 kHz/hour, 8642A/B bands 1-9, HET.
<8 kHz/hour, 8642B band 10.
FM Stereo Separation, Ext de-Coupled, HET Band (Special
Function 8): >50 dB, 1 kHz rate, 75 kHz deviation.
Low Distortion FM/$M (Special Function 5 or 112): Distortion
in either FM or #M can be reduced with this function.
FM stereo separation unaffected.
FM Distortion in Special Function 7: <0.03% THD, <1/15
maximum deviation, external rates <50 kHz and inter­
nal rates <15.8kHz.
FM Pre-emphasis (Special Function 6): Provides pre-
emphasis in FM with a 750 ^s time constant. This is
useful when testing FM communications receivers.
AMPLITUDE MODULATION
(for V0R, ILS, Avionics Applications)
AM Phase Shift, DC Coupled, for Carrier Frequencies From
108 MHz to 118 MHz:
30 Hz rate: <±0.01°.
30 Hz to 10 kHz rate: <±3°.
Difference from 9 kHz to 11 kHz rates: <2°.
AM Flatness, DC Coupled External AM:
<0.04 dB, 90 to 150 Hz, 108 to 118 MHz and 329
to 335 MHz. (<0.00092 DDM @ 20% AM and
<0.0019 DDM @ 40% AM.)
<0.1 dB, 9 to 11 kHz, 108 to 118 MHz.
OUTPUT
Absolute Accuracy: ±3 dB, output level < - 1 2 7 d B m .
Output Level Switching Time: <100 ms from receipt of last
controller command.
Amplitude Sweep, in CW and Angle Modulation Modes:
Range: 20 dB log (or linear with Special Function 122)
sweep (10 dB underrange available).
Sweep Time: 20 ms minimum, 999s maximum.
Accuracy: ± 1 dB over highest 10 dB. ±3 dB over sec­
ond highest 10 dB.
Attenuator Range Hold (Special Function 9): The internal
step attenuator can be fixed and the electronic level
vernier varied up to 30 dB for monotonic level setting.
This is useful in measuring of receiver squelch
hysteresis.
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