ICW orginally was CW interrupted at AF with an interrupter wheel.
See p. 129 of 'Radio Engineering' ed. Roy C Norris, pub. Odhams Press
----- Original Message -----
From: Väinö Lehtoranta <[email protected]>
To: <[email protected]>
Sent: Wednesday, January 31, 2001 2:23 PM
Subject: Re: LF: CW etc
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)
-----------------
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
>
>
|---------------------------------------------------------|
| V.K.Lehtoranta, OH2LX ¤ 60N33.6 024E58.7 KP20LN74 |
| P.O.Box 50 ¤ Telephone: +358-9-4173965 |
| FIN-05401, Jokela ¤ Telefax: +358-9-4173961 |
| Finland ¤ email: [email protected] |
|---------------------------------------------------------|
| 