> 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
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