Hello all,

Look for example "MIL-STD-188-140A" Appendix A
............
20.2.1 Interrupted continuous wave (ICW)

ICW or on-off keying (usually associated with
international Morse Code) can be used with
VLF and LF systems, but is presently used only
as a back-up. In the case of fixed shore base
installations, ICW data rates are severely
limited by the time constant of the antenna
circuit......etc

20.2.2. Continuous wave frequency shift keying (CWFSK)

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73 de Vaino






At 11:48 31.1.2001 +0000, you wrote:

In message <[email protected]>, Walter
Blanchard <[email protected]> writes

For some reason this didn't seem to make it onto the reflector first time round so here goes again:

snip

"CW" - "continuous wave" - means just that; a steady unbroken unmodulated carrier wave; "N0N" (or "A0" in old money). Morse code is mainly sent by interrupting the carrier so how can it possibly be "CW"?

The old spark transmitters, produced damped wavetrains which carried
their own modulation (rough). When the arc system was produced which
gave a continuous waveform these were designated 'CW'. They required a
beat oscillator to hear them and even though they were interrupted by
the keying the nomenclature stuck.

Mike

Only amateurs consider "Morse" and "CW" to be synonymous which is a pity because it clouds our thinking.

Commercial and armed forces transmitters have the Morse position
labelled 'CW' on the switch.

Mike
--
M.J.Powell

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