HP 8642A Operating Manual page 145

Model 8642A/B
Operation
MODULATION, $M
Description The Signal Generator can phase 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/SM INPUT.
Depending on the RF frequency selected, the 8642A/B has different limits on the
possible *M deviation that can be selected. (See Figure 3-1 5 on page 3-120.) The Signal
Generator normally selects the divide bands 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
deviation *M at RF frequencies less than 132.187501 MHz. (Refer to RF Frequency,
page 3-39, for more information about these different bands.)
Table 3-22. $M Operating Characteristics
Electrical
Characteristics
$M Deviation Limitations
Accuracy
Resolution
Distortion
* M 3 dB Bandwidth
Performance
Limits
See Figure 3-15
±(5% of setting +0.09 radians)
0.7% of setting or
0.0004% of maximum deviation
(whichever is larger)
<0.4%
20 Hz to 15 kHz
dc to 15 kHz
Conditions
1 kHz rate
1 kHz rate
Internal and external ac
External dc