Modulation, Am - HP 8642A Operation And Calibration Manual

Model 8642A/B
Description
Procedures
Operation
MODULA TION, AM
The Signal Generator can amplitude modulate its RF output either with a variable
internal modulation oscillator and/or with an ac- or dc-coupled external source
applied to the AM/PULSE INPUT.
When amplitude settings exceed +14.0 dBm (l.12V, 121.0 dBuV, 2.25 EMF V, and
127.0 dB EMF uV), the AM depth setting is limited. (Refer to Table 3 -18 on page
3-102.)
Table 3-17. AM Operating Characteristics
Electrical
Performance Limits Conditions
Characteristics
AM Depth
0% to 99.9% Output Amplitude
~+10
dBrn
1
(707 mV, 1.41 EMF V, 117.0 dBI'V,
123 dB EMF IN)
Resolution 0.1%
AM Indicator Accuracy :!:(3.5% of setting 1·1% AM) 8642A bands
3
1-8, HET;
(1 kHz rate, up to 90% AM)
8642B bands 1-9, HET
:!:(5% of setting
±
1% AM)
8642A bandS 9,
8642B band 10
AM Distortion at 1 kHz rate 8642A Bands 1-8;
8642B Bands 1-9
<1% 0% to 30% AM
<2% 30% to 70% AM
<4% 70% to 90% AM
8642A Band 9, HET;
8642B Band 10, HET
<2% 0% to 30% AM
<4%
30% to 70% AM
<6% 70% to 90% AM
AM 3 dB BandWidth
de to 100 kHz
External dc, bands 2 1. 5 thru 10
(Depttl
~90%)
20 Hz to 100 kHz External ac and internal,
bands 3
1. 5 thru 10
de to 20 kHz External dc, bands
2 •
s 2, 3, 4
20 Hz to 20 kHz External ac and internal, bands 2 . 3 2. 3, 4
Incidental <PM <0.2 radians peak
(1 kHz rate and 30% AM)
1lt is possible to set AM with an output amplitude above this limit However, its modulation characteristics are root specified
2Specific band information is available in Table 3-11
SAM
bandwidths up to 100 kHz can be obtained by selecting Special Func:ion 8 (Prefer Heterodyne Sand)
Note: Put the instrument in its initialized state by selecting ( INSTR PRESm.
AM can be configured
to
use either the Signal Generator's internal modulation
oscilla tor, an external source, or combinations of the two sources.
3-97