QCX assembly Rev 1.08
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7.4
Class-E Power Amplifier drain waveform
This oscilloscope chart shows the waveform at the BS170 drains (top, RED colour trace) and the
input drive waveform, a 5V peak-peak squarewave (bottom, BLUE trace). The 40m band is shown.
Upon ignoring the “ringing” artefacts due to poor ‘scope probes etc., the waveforms are correct for
Class-E operation.
7.5
RF envelope key-shaping
The following oscilloscope images show the RF envelope when keyed with a continuous 24 words
per minute (50ms duration) string of dits. The simple key-shaping circuit described earlier results
in rise/fall times of around 5ms and significantly attenuates key-clicks.
Содержание QCX 5W CW
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