Here are two views of the audio recording of W4BXI's keying. (Click on the image to magnify.) The first shows amplitude vs frequency for a portion of the initial dit. A fairly sharp peak is seen near 622 Hz. The amplitude above the peak rolls off more slowly than I expected, and this shape is also seen when I analyze just the noise waveform between CW characters. It might relate to the audio filter mode or some other noise entering the recording.
The second figure shows the amplitude and frequency content vs time as in the previous post for the recording of keying from KB4XX. Except for some brief additional high-frequency content near the beginning and end of each CW character, the tone is steady for the duration of each character.
Many, many other views can be obtained by choosing the time portion of a waveform to be analyzed.
-- John
No comments:
Post a Comment