Please refer to your User Guide for selecting the AM / FM / PM Analyzer mode and for setting up basic functions such as GPS, limit lines, markers, and file management.
While a parameter value is being changed, the value is displayed in red both on the submenu key face and in the sweep window.
1. Connect an antenna that is suitable for the measurements.
2. Press the Setup main menu key and then press the Demod Type submenu key to toggle the setting to AM, FM, or PM signal analysis. The active setting is underlined on the submenu key face.
3. While in the setup menu, you may choose to set the IFBW (IF Bandwidth) or to turn On or Off the automatic IFBW (by pressing the Auto IFBW submenu key). The available values for IFBW are: 1 kHz, 3 kHz, 10 kHz, 30 kHz, 100 kHz, and 300 kHz.
If the Auto IF BW function is On, then manually changing the IFBW turns it Off. When the Auto IF BW function is On, the IFBW is automatically changed to the closest value that is greater than, or equal to, the span. If the span is greater than 300 kHz, then the IFBW is set to 300 kHz.
4. Press the Freq main menu key and press the Center Freq submenu key to set the desired center frequency. In RF Spectrum measurements, press the Set Carrier Freq to Center submenu key to adjust the signal position to the center of the display screen. Or, you may also choose a Signal Standard, which sets the frequency.
Note
If Demod Type is set to FM or PM, then the Set Carrier Freq to Center function aligns the carrier to center only if the carrier is within the IFBW from the center frequency.
5. Press the Signal Standard submenu key to open the list of Signal Standards. Choose a signal standard and press the Enter key. The current signal standard is displayed at the top of the sweep window. The frequency is automatically set when the signal standard is selected.
6. If you used Step 5, press the Channel submenu key to open the Channel Editor list box and set a channel.
7. Press the Span submenu key to open the Span menu and to set a span value.
8. Press the Amplitude main menu key to open the RF Amplitude menu. Here you may set the scale or the power offset.
9. Press the Measurements main menu key to open the Measurements menu.
10. From the Measurements menu, choose RF Spectrum, Audio Spectrum, Audio Waveform, or Summary.
Note
Measurement values for SINAD, THD, and Distortion/Total apply only to single tone modulation. For better accuracy of these measurements, the modulation rate should be at least 0.7 % of IFBW.
11. If the RF Spectrum graph displays “ADC error”, then press the Amplitude main menu key and then press Adjust Range. Pressing the Adjust Range submenu key sets the Y‑axis reference level based upon the signal strength. If the signal is too large (ADC error) or too low, then pressing this key sets the reference level such that the signal is displayed fully within the sweep window. The peak may be close to second grid from the reference.
12. To listen to the audio component of an AM or FM signal, press the Audio Demod submenu key. Audio demodulation is not available for PM signals.
13. In the Audio Demod menu, press the On / Off submenu key turn On or Off the audio demodulation function. A Demod Type submenu key is available, as well as a Volume submenu key.
14. To save or recall setups or measurements, press the Shift key and the File (7) key. Setup files are saved with a .stp extension, and measurement files are saved with a .afp extension.
15. Setups may also be saved or recalled by pressing the Shift key and the Preset (1) key. Refer to your instrument User Guide for details.