How to save data from the signal analyzer
The signal analyzer we have in the lab is a HP35665A
, one that's borrowed from Dr. Cremaldi. Elog #59
explains in detail the saving process. However, based on the measurement, the saved data on floppy disk would be different. The two main measurements we make in the labs are:
- * Transfer function measurement
- In this case, the saved data has three columns. The first column represents the frequencies. The second and third column show the real and imaginary part of the amplitude of the transfer function, respectively.
- * Noise floor measurement
- In this case, if you are measuring the power spectral density (PSD), the saved data has two columns. The first column is the frequencies and the second column has the PSD amplitudes.
As it is mentioned in the elog #59, you need to install an emulator e.g. DOSbox on your computer to be able to convert .DAT to .TXT. After copying the saved file into C:dosprogs\disk1, open DOSbox and type the following commands and press enter after each command:
- mount c c:\dosprogs
- cd disk1
- sdftoasc nameoffile.DAT /x nameoffile.TXT
The above commands are for transfer function measurements conversion. For the second cases, noise floor measurements, the last command has a following additional term:
- sdftoasc nameoffile.DAT /x nameoffile.TXT /Y:PRD
Notice: Although the extra term does not change the trend of the graph, it gives the correct amplitude of PSD as it is shown in the Signal Analyzer.