Vision™ MX280001A Spectrum Monitoring Application Software : AM/FM Measurements (Option 479) : Introduction : Open the Radio Capture File
 
Open the Radio Capture File
1. Locate the radio Capture Program from the your Start menu or file folder. Depending on your version of Windows, the program may be located in the Vision Tools folder.
2. Open to display the user interface shown below in Figure: AM/FM Measurements.
AM/FM Measurements
The AM/FM Measurements menu provides a way to:
• Sweep a range.
• See the sweep trace.
• See a peak in the trace.
• Click on the peak to select the frequency for the audio streaming.
• Set Reference Level (dBm) using the scroll reference level selector.
You select a start and stop frequency for the trace graph. Click the 'Play' button starts sweeping that range and you see the traces in the graph. When you see a peak you are interested in, you stop sweeping and float your mouse over the graph display, which scrolls the graph as a green marker, and click on the peak that sets the frequency (box above the graph) to the peak position. The bandwidth (span) for the IQ capture and audio streaming are automatically set by the type of audio signal (AM, FM, or NBFM).
If the user knows the frequency of the signal they are interested in, they can skip this step altogether and just type the frequency in the box provided. The graph is used to select a peak (frequency) to test (either FM deviation, AM modulation, or Streaming audio). However, the user can enter it from the keyboard and not use the graph. The graph will typically have a much wider span than the bandwidth of the signal you want to test, and the signal is unlikely to be at the center frequency of the graph.
Example
If you are interested in streaming a radio station from the US FM broadcast band, you would set the Start and Stop frequencies to 88 MHz and 108 MHz. That is the FM band. Then you can sweep and see that there are quite a few peaks in the trace data, each representing a particular radio station. If you want to listen to one of them, you click on the peak, 106.5, for instance. That frequency is then set as the test frequency. Doing the measurements, or streaming, will use the bandwidth of the signal type selected, not the full span of the trace graph.