Message-ID: <3.0.6.32.20010131162350.0082a100@pop.saunalahti.fi>
Date: Wed, 31 Jan 2001 16:23:50 +0200
To: rsgb_lf_group@blacksheep.org
From: =?iso-8859-1?Q?V=E4in=F6_Lehtoranta?= <vaiski@dlc.fi>
Subject: Re: LF: CW etc
In-reply-to: <WaZ3cNAgu$d6EwL8@pickmere.demon.co.uk>
References: <5.0.2.1.2.20010131074711.00a3d680@mail.pncl.co.uk> <5.0.2.1.2.20010131074711.00a3d680@mail.pncl.co.uk>
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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 <5.0.2.1.2.20010131074711.00a3d680@mail.pncl.co.uk>, Walter
>Blanchard <blanch@pncl.co.uk> 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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