96000 Series
Service Manual
3-16
9. On the UUT, push the Modulation Select softkey and select frequency
modulation (FM). Set the UUT as follows:
Frequency 62.5 MHz
Level +13 dBm
Mod Rate 1 kHz (Sine)
FM Deviation 300 kHz
Output OPER
Modulation OFF
10. Use the Measuring Receiver autotune feature to tune to the input signal and
when tuning is complete set the UUT to Modulation ON.
11. Measure the FM rate. Verify that the measured rate is within the tolerance
listed in Table 3-8.
Note
For accurate FM measurements, the Measuring Receiver’s setting
demodulation bandwidth setting must be >3 x {rate + deviation}. To
meet this requirement at higher rate and deviation frequencies the
demodulation bandwidth setting must be increased from the default
automatically configured in the modulation measurement mode.
Table 3-8. FM Rate Test – Levelling Head (96040A and 96270A)
Level Frequency
Modulation
Rate
Deviation Tolerance
+13 dBm
62.5 MHz 400 Hz 30 kHz ±0.11 Hz
62.5 MHz 300 kHz 1 MHz ±10 Hz
12. Set the UUT as follows:
Frequency 125 MHz
Level +13 dBm
Mod Rate 1 kHz (Sine)
FM Deviation 1 kHz
Output OPER
Modulation OFF
13. Use the Measuring Receiver autotune feature to tune to the input signal
and when tuning is complete set the UUT to Modulation ON.
14. Measure the FM deviation. Verify that the measured deviation is within the
tolerance listed in Table 3-9.
15. Repeat step 14 for the remaining FM deviation test points listed in Table 3-
9. When setting a new carrier frequency, select MODULATION OFF and
repeat step 13 prior to repeating step 14.
16. Set the UUT output to STBY. Remove all connections to the Leveling Head.
To Next Page
Loading...
