Tabor Electronics 5251, User Manual

Page: 233 / 298

5
Performance Checks
Test Procedures
5-11
Sinewave Spectral
Purity, DDS Output
Equipment: Spectrum Analyzer
Preparation:
1. Connect 5251 output to the spectrum analyzer input. Use 50
Ω
and 20 dB feedthrough termination at the spectrum analyzer
input
2. Configure the 5251 as follows:
Waveform: Modulated
Modulation:
OFF
Amplitude: 5 V
Output: On
CW Frequency: As required by the test
Test Procedure:
1. Perform sinewave spectral purity, DDS Waveforms tests using
Table 12
Table Chapter 5-12, Sine Wave Spectral Purity, DDS Output Tests
5251 Freq Reading Spectrum Analyzer Settings
Settings Limits Start Stop Reading Pass Fail
10 MHz >45 dBc 1 MHz 100 MHz
50 MHz >30 dBc 10 MHz 200 MHz
100 MHz >30 dBc 10 MHz 250 MHz
Sinewave Flatness,
DAC Output
Equipment: Oscilloscope
Preparation:
1. Configure the Oscilloscope follows:
Termination: 50
Ω
, 20 dB feedthrough attenuator at the
oscilloscope input
Setup:
As required for the test
2. Connect 5251 output to the oscilloscope input
3. Configure the 5251 as follows:
Amplitude: 5 V
Output: On
Frequency:
Initially, 1 kHz then, as required by the test
Test Procedure:
1. Adjust the vertical controls of the Oscilloscope to get 6 division
of display
2. Perform Sine flatness, DAC waveforms tests using Table 13