HP 8642A Operation And Calibration Manual

Model 8642A/B
Descdption
Operation
MODULATION, FM
The Signal Generator can frequency modulate its RF output either with a variable
internal modulation oscillator, and/or with an ac- or dc-coupled external source applied
to
the FM/<pM INPUT.
Depending on the RF frequency selected, the 8642A/B has different limits on the
possible FM deviation that can be selected. (See Figures 3-12 and 3 -13 on the following
page.)
The Signal Generator normally selects a divide band to obtain its FM deviation.
However,
if the divide band's maximum internal FM deviation boundaries are crossed, the
Signal Generator can automatically switch to the heterodyne band which allows wider
FM deviation at RF frequencies less than 132.187501 MHz. (Refer to RF Frequency,
page
3-39, for more information about these different bands) If FM Pre-emphasis is
selected, more limitations are placed on FM deviation and modulation frequency. (Refer
to the discussion about fM Pre-emphasis starting on page 3-113 under "6. FM
Pre -emphasis On".)
Table 3-19. FM Operating Characteristics
Electrical Characteristics Performance Limits Conditions
FM Deviation Limitations
See Figures 3-12 and 3-13
Indicator Accuracy ±(5% of setting
+10 Hz)
(Rates from 20
Hz to 100 kHz)
Resolution
0.7% of setting
or 0.0004%
of maximum deviation
(whichever is larger)
FM Distortion 4%
For maximum dc-coupled deviation
(Rates from 20 Hz to 100 kHz) 2% For
'/
2
maximum dc-coupled deviation
0.4%
For
'/15 maximum dc-coupled deviation
FM 3 dB Bandwidth
de to 200 kHz
External
dc source
20 Hz to 200 kHz External ac source
20 Hz to 100 kHz Internal source
0.4 Hz to 200 kHz (with
Special Function
5)
3-105

HP 8642A Specifications

General

Brand	HP
Model	8642A
Category	Inverter
Language	English