I have always thought of "MCW" as an AM signal - used so that receivers
with only AM capability could copy them.
OTOH, if a SSB signal with sufficient carrier and opposite sideband
suppression is presented with an undistorted sine wave signal, it can be
just as good as a CW signal. Unfortunately, all those conditions are
not satisfied with CW in SSB where an open mic is also present.
73,
Don W3FPR
On 6/15/2013 6:40 AM, David Woolley (E.L) wrote:
Most modern commercial transceivers effectively generate CW as SSS
MCW. I think the K3 does it at about 15kHz or less, which is within
the audio range. I suppose the K3X could generate it directly, by
just keying the I signal to the modulator; however, that would mean
moving the VFO between transmit and receive, at the QSK rate. (Keying
I on the K3 would probably be a bad idea, as it would mean that any
transmit roofing filter would need to pass the first LO frequency and
therefore be subject to some carrier leak when key up, so I presume
that the CW is actually synthesized as fully fledged MCW. Even if it
keyed I, you could treat that as MCW with a side tone of 15kHz.)
Even the K2 architecture is effectively an MCW one, but in that case
the initial tone is in the MHz range.
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