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RE: What is CW?

Fr. Tom,
With all due respect to you and your great expertise in this area I offer
this minor correction to your explanation of CW as it is critical in the
understanding of information technology.  CW, by the IEEE Standard, means
continuous wave, although it is used as a carrier wave in most
communications.  The definition also goes one step further in that it
specifies that each oscillation is identical.  Therefore, there can be no
variation in amplitude frequency or phase as this would imply modulation.
And for the originator of this question, modulation is how a continuous wave
is altered due to the information that is imposed onto(or mixed with) it.

I hope this helps.


Russ Thornton
Sr. Radar Systems Engineer
CSR 2040, 
Building 989, Rm.  A1-N20
Phone: (407) 494-6430 
Email: thorntor-at-rc.pafb.af.mil


> ----------
> From: 	Tesla List[SMTP:tesla-at-pupman-dot-com]
> Sent: 	Sunday, September 13, 1998 3:17 PM
> To: 	tesla-at-pupman-dot-com
> Subject: 	Re: What is CW?
> 
> Original Poster: "Thomas McGahee" <tom_mcgahee-at-sigmais-dot-com> 
> 
> 
> Dr B.,
> CW stands for Carrier Wave. It indicates a constant oscillation,
> such as a continuous sine wave. (The amplitude may change,
> but the frequency would be constant). This is the type of
> waveform that you would encounter in a tube type Tesla Coil.
> 
> The standard Tesla Coil uses the disruptive discharge of a 
> capacitor, and if you looked at the waveform on an oscilloscope
> you would see a train of pulses that comprised short bursts
> of oscillation (ringing) at the resonant frequency. This
> is pulse mode, as opposed to CW mode.
> 
> In CW mode energy is added to the circuit continuously,
> in phase with the oscillation of the tank. In pulse mode
> the energy is delivered somewhat haphazardly, at varying
> intervals, and without regard to phase. In fact, the pulses are
> usually delivered only after the previous ringing has ceased.
> 
> CW mode is harder to achieve, especially at the higher power
> levels. Some persons are interested in using Poulsen-type
> CW units to power Tesla Coils. The results would look more
> like the output of a Tube Tesla Coil. In other words, the
> output would take the form of a fiery brush discharge rather
> than the noisey machine-gun type bolts and arcs that most
> coilers are familiar with.
> 
> Running a TC in CW mode would most likely cause more
> radio interference and problems with one's neighbors, too.
> 
> Hope this helps.
> Fr. Tom McGahee
> 
> ----------