Topband: Digital mode spurious issues

[Tom W8JI]

> Actually, IMD can be produced by ANY keying waveform -- for example, the 
> envelope of a CW  or RTTY signal.

Let's not divert the issue.

A rise and fall is always composed of many frequencies making up sidebands, 
otherwise it would have no shaping. Even CW is an AM signal, when we look at 
rise and fall.

We are not talking about momentary sidebands generated during level 
transitions. We are talking about spurious signals up and down the band.