[CW] Speed vs Bandwidth

Tue, 16 Mar 2004 01:31:20 -0500

Pedro,

I originally asked the question.  While I didn't expect it to be such an
elaborate or technical response, I did learn something from it.  I have
been following the thread which has diverted a little to a few people
disagreeing with each other, but in a most peaceful and respectable way.

I appreciate all the responses I thus far.  I am sorry you aren't tuned
into this topic with the same attitude I and some others are.  

I wish you well in finding a topic for your "younger fellows", but
please respect those of us willing to learn more about the advanced
theories and practices.

Thank you.

Buck

> -----Original Message-----
> From: Pedro J. Santa [mailto:[email protected]] 
> Sent: Monday, March 15, 2004 11:40 PM
> To: David J. Ring, Jr.; George, W5YR; [email protected]
> Subject: [CW] Speed vs Bandwidth
> 
> 
> Hi all:
> 
> I've been following (or trying to) the multiple exchanges on 
> the referenced topic--most of which are really devoted to 
> esotheric postulates and futile diatribes, to say the least.. 
> I don't think I've learned much of any significance from this 
> long, just too long,  string of messages regarding this 
> impractical and theoretic subject.  I can only say that this 
> hogwash has not really added much, if anything, to my 
> enjoyment of the hobby--much less to my passion for Morse 
> Code.  If our younger fellows were reading the colloquy about 
> this nonsense, they would just join the ranks of those who 
> claim we ham radio operators have "lost it"...
> 
> 73 Pedro..
> 
> P.S. Morse Code is forever...
> 
> 73 Pedro KP3X----- Original Message ----- 
> From: "David J. Ring, Jr." <[email protected]>
> To: "George, W5YR" <[email protected]>; <[email protected]>
> Sent: Tuesday, March 16, 2004 12:09 AM
> Subject: [CW] We agree - Speed vs Bandwidth
> 
> 
> > W5YR wrote:
> >
> > Grab your 2003 ARRL Handbook and look at Fig. 12.21 on Page 
> 12.13 - I 
> > imagine that the 2004 and 2002 books have the same content in about 
> > the
> same
> > location.
> >
> > Fig. 12.21 is a graph that relates bandwidth to rise/fall 
> time. Keying
> speed
> > does not enter into the graph at all for the spectral width 
> > determination. It does indicate the maximum keying rate for 
> a K=3 and 
> > a K=5 circuit for a given bandwidth. Nowhere in the material on CW 
> > keying could I find any mention of keying rate influencing 
> bandwidth.
> >
> //////////////////////////////////////////////////////////////
> /////////////
> >
> > I really wold like to see what they say for maximum keying 
> rate at K=3 
> > and K=5 - can you post that?
> >
> > I agree with you - and your observations agree with me! - the 
> > bandwidth
> goes
> > up with code speed, but the bandwidth is much more affected by the 
> > wave shape.
> >
> > So - we've exhausted that interesting topic.  We agree!  How boring!
> >
> > I might make a sound file and feed it into my IC-756PRO and 
> change the 
> > "voice rate" as I mentioned - that would be a hoot.  I am sure the
> bandwidth
> > would go up with the voice rate pulses - so we could have a 
> new thread
> about
> > bandwidth goes up when you talk fast (or at least if you make faster
> > pulses!)  But we need a new email reflector - how about "CW 
> guys who 
> > think they're SSB operators" email list?
> >
> > George, you can find the relationship between keying speed (baud or 
> > baudot
> > rate) and bandwidth here on the ITU web site:
> >
> > http://life.itu.ch/radioclub/rr/sm1138.htm
> >
> >
> > AMPLITUDE MODULATION
> > 1. Signal with Quantized or Digital Information Continuous wave
> telegraphy,
> > Morse code Bn = BK
> > K = 5 for fading circuits
> > K = 3 for non-fading circuits
> >
> > 25 words per minute; B = 20, K = 5  Bandwidth:100 Hz
> >
> > Telegraphy by on-off keying of a tone modulated
> > carrier, Morse code Bn = BK + 2M
> > K = 5 for fading circuits
> > K = 3 for non-fading circuits
> >
> > 25 words per minute; B = 20, M = 1 000, K = 5
> > Bandwidth: 2 100 Hz
> >
> > 73
> >
> > David Ring, N1EA
> >
> > _______________________________________________
> > CW mailing list
> > [email protected]
> > http://mailman.qth.net/mailman/listinfo/cw
> 
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