Giga-tronics 2508A, Operation Manual

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Performance Verification
2500A Series Operation Manual, 34172 Revision C, March 2008
Span 50 MHz
Sweeptime 400 msec.
Resolution Bandwidth: < 100 kHz
Video Bandwidth:
> 30 kHz
4. Set the level of the UUT to 0 dBm, activate the RF output, and set the external FM settings of the
UUT to the following:
FM State: Off
Mode: Wide
Sensitivity: 10 MHz/volt
5. Set the output of the UUT to the first frequency in datasheet. (Add cross-reference to the datasheet
at end of chapter) and adjust the spectrum analyzer frequency to match the test frequency. Adjust the
reference level of the spectrum analyzer until the peak on the top graticule of the display.
6. Set the FM State to On.
7. Adjust the rate of the function generator until the FM carrier is -50 dBc or greater (Bessel Null)
from the unmodulated signal reference on the spectrum analyzer.
8. Using the following formula, determine the FM Deviation of the UUT. Record the result in
Datasheet #9.
Deviation = 2.4 * Rate
(Function Generator)
2.4 is the Bessel Null 1st Order Carrier Zero
9. Repeat steps 5 through 8 for the remaining frequency test points.
4.3.3.3 Pulse Modulation Tests
The following procedures test Pulse Modulation Level Accuracy, On/Off Ratio, and Rise/Fall times at
frequencies within each band. The tests require a fast crystal detector (rise time < 10 nsec).
4.3.3.3.1 Equipment Required
• Oscilloscope (300 MHz bandwidth recommended)
• Crystal Detector (< 10 nSec rise-time, frequency range equivalent to test frequency range)
• Spectrum Analyzer (0 Hz span capable)
• Power Meter
• Power Sensor
• Pulse Generator