[CQ-Contest] CW Band width

Tom Rauch W8JI at contesting.com
Mon Feb 26 20:10:12 EST 2001

 > If a modern synthesizer is used to key the radio and the radio is not
 > running in full QSK mode (or if separate synthesizers are used for RX
 > and TX), I suspect that the only time settling and bounce should be
 > (possibly) important is for the first cw symbol.  Subsequent symbols
 > should be stable as far as settling and bounce is concerned.

I've heard that difference in a 775DSP when on QSK and on semi-
breakin. At least some 775's let out a "thump" on the receive
frequency and between the receive frequency and transmit

When you get the operators to use VOX instead of QSK, the
thump only occurs at the leading edge of each receive to transmit
transition. Depending on the VOX delay, that can make a day and
night difference in QRM.

Even so, any emission like that is a problem because of the
number of people that can be active at one time.

 > It would be useful for some authority to publish a good article on
 > band width that covers cw, ssb, rtty, and psk. I suspect that most of
 > us have a rather vague notion (mostly associated with crystal filter
 > widths) of what bandwidth really is.  I suggested that the ARRL
 > publish such an article - however I have received no reply.

I think it would be neat to get a few rigs together at a large
gathering,  measure them, and let everyone listen to them on a real
good receiver through simulated background noise as various
things are changed.

Or maybe people wouldn't want to know?
73, Tom
(W8JI at akorn.net) 

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