[CW] Speed vs Bandwidth

[David J. Ring, Jr.]

Buck,

A CW signal that is "interrupted" by a fast switch has a very wide
bandwidth - this is called I.C.W. (Interupted Continuous Wave) and was used
on receivers that were also used for detection of spark.  Spark and ICW both
had modulation.  The modulation on the ICW signal was directly proportional
to the speed of the interupter - which was keying the CW signal at an audio
rate.

In other words, the CW was being keyed at 400 times a second by the ICW
"chopper" so that it would produce a 400 cycle per second audio tone, then
the "chopped" CW was keyed at a 20 or 25 wpm rate to send a message.  The
chopper could be turned off, and the bandwidth of the signal went way down.

Remember - there is no modulation on the carrier except that which is done
by on/off keying.

73  de N1EA
----- Original Message -----
You folk might have to forgive me, but I can't immagine that there is
actually a cw speed that could consume the entire 80 meter ham band.