Dan Tayloe wrote:
This is indeed what happens only if the VFO and an incoming single are
at almost the same frequency ("zero beat"). However, in practice, if
the signal is a cw signal, we listen to a signal that is 600 Hz or so
away from the VFO so that we hear the 600 Hz tone difference.

....or at least, say, 595-605Hz is the local oscillator tends to drift +/-5Hz
over time, eh? Good enough.

With SSB, presumably you have the same 'problem' -- the entire voice signal
is shifted in pitch by the difference between the LO and the real carrier.
In fact, with SSB and direct conversion, how do you even decide you have the
correct LO frequency? Just when people sound 'most natural?'

Thanks,
---Joel Kolstad