Topband: Re: Weak Signal Reception (EME view)

[Bill Tippett]

I wrote:
 >I recall an approximate estimate for keyed CW bandwidths is
about 4 times the keying speed.

         Turns out that was from my memory from an FCC test
question years ago...and it is incorrect!  The keyed bandwidth is
much more a function of the rise and fall times of signal waveforms,
as we're all too painfully aware of due to experience with certain
clicking radios being sold.  Here are a couple of references about
keyed bandwidth:

"Spectral Analysis of a CW keying pulse"  by W9CF

http://fermi.la.asu.edu/w9cf/articles/click/

"On the Occupied Bandwidth of CW Emissions" by KF6DX (TenTec)

http://www.doug-smith.net/cwbandwidth1.htm

         Maybe the moral of this is to clean up your clicks if you
want to be heard well in very narrow filters!  ;-)

                                         73,  Bill  W4ZV