Topband: Keying waveform

[Paul Christensen]

> in a new design, so that probably is what rules it out. Another way would
be
> to just send the nasty CW through a narrow crystal filter and use linear
> amps beyond that point.

As long as the CW signal is reasonably centered within the xtal filter
passband, this is a good suggestion.  However, if the signal falls
off-center and is placed on the sharp knee of the filter, some very strange
results occur.

For example, the stock Omni Six/Six Plus is characteristic of this.  On some
Omnis, the 9 MHz CW transmit BFO is placed dangerously close to the lower
skirt of the 2.4 @ 9 MHz filter.  The effect is both heard and seen on a
scope.   It seems that some Ten Tec 2.4K filters are constructed more
accurately than others.

-Paul, W9AC