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[TenTec] Ringing in Filters at High Speed CW

To: <tentec@contesting.com>
Subject: [TenTec] Ringing in Filters at High Speed CW
From: <al_lorona@agilent.com>
Reply-to: tentec@contesting.com
Date: Sun, 15 Aug 2004 18:20:47 -0600
List-post: <mailto:tentec@contesting.com>
Tom, I meant to ask you this when the subject of 100 wpm CW first came up in 
this thread a while ago. Thus, I have changed the name of this sub-thread.

When you're receiving CW that fast, how much does the ringing of the various 
filters in the radio affect you? I would imagine that at those speeds, ringing 
starts to fill in the spaces between the dits, making it very difficult to deal 
with. I would guess that when you're going that fast, that you use the widest 
possible filter settings, right?

Al  W6LX



> -----Original Message-----
> From: tentec-bounces@contesting.com
> [mailto:tentec-bounces@contesting.com]On Behalf Of Tommy
> Sent: Friday, August 13, 2004 3:19 PM
> To: tentec@contesting.com
> Subject: Re: [TenTec] DSP in CW transmit? 
> 
> 
> I think some are getting hung up on the 100 wpm thing. And 
> the speed is not
> the point...the point is just the FUN of doing something like 
> that. Since my
> two strokes, I'm lucky to be doing much between 70 and 80 
> wpm. 100 wpm may
> be a thing of the past for me, but there is now no one around 
> to try it
> with.
> 
> Believe it or not, there is more 'full duplex' going on at 
> 100 wpm than
> there is at 40 wpm. It's basically not much difference from using a
> different language and talking to someone on a telephone.
> 
> The discussion about DSP is moot. It's here and it has to be 
> in every radio
> so manufacturers can claim to be  with the state of the art. I have to
> accept that, and I do. But that is not going to hinder me in 
> enjoying part
> of this hobby that I enjoy, it just means I have to hold on 
> to the older
> rig's that will function in the CW mode the way I want mine 
> to function.
> 
> Heck, I enjoy rag chewing at 30 wpm just as much as I enjoy 
> rag chewing at
> 70 wpm. What I DO NOT enjoy is paying $3700 for a radio that 
> will not even
> function well at the 30 wpm level.
> 
> Tom - W4BQF
> 
> ----- Original Message -----
> From: "n4lq" <n4lq@iglou.com>
> To: <tentec@contesting.com>
> Sent: Friday, August 13, 2004 3:47 PM
> Subject: Re: [TenTec] DSP in CW transmit?
> 
> 
> > There is some truth here but it still doesn't discourage us 
> QSKers from
> > pursuing our goal. Learning to live with no QSK is not an 
> option for us.
> > Certainly, the breaker must send more than a few characters 
> in order for
> > the breakee to hear him since some of the breakers characters will
> > coincide with the timing of the breakee's characters and 
> not be heard.
> > Now for these guys going 100 wpm....By the time they are broken, the
> > breakee will have sent an entire paragraph and the breaker may have
> > forgotten why he broke in the first place. I don't think 
> there is a whole
> > lot of duplex cw going on at 100 wpm but there are quiet a 
> few at 30 wpm.
> > Noting is quite as satisfying as a full duplex cw qso. I 
> find the silence
> > between the characters of semi-BKin eerie and frustrating, 
> thinking all
> > along that something may be going on that I need to hear!
> > n4lq
> > -----Original Message-----
> > From: Lee Crocker <w9oy@yahoo.com>
> > To: tentec@contesting.com
> > Date: Fri, 13 Aug 2004 12:02:20 -0700 (PDT)
> > Subject: [TenTec] DSP in CW transmit?
> >
> > > But it's not just the generation of the waveform that
> > > is occurring in the DSP, it's also the time it takes
> > > when you go from transmit to receive for the received
> > > signal to get through the DSP filter and into your
> > > ears.  This takes time, and is occuring during the
> > > time you would normally be listening for the
> > > "break-in" in the QSK cycle.  Just about the time a
> > > breakin from the station you are working would occur,
> > > the audio is switched, you're back in transmit, and
> > > the side tone is now being routed to your ear.
> > >
> > > So the time that used to be devoted to listening for a
> > > break is now being used to process the received
> > > breakin signal and just as it is about to get to your
> > > ears, it then gets lost as the rig goes to transmit,
> > > and the next character is generated and transmitted.
> > > During this period of transmission the recieve
> > > processing is halted and its not until the received
> > > breakin signal starts into the DSP again that
> > > processing begins anew.
> > >
> > > Hence my original question, how much QSK is really
> > > necessary?  Is it enough that you can be broken during
> > > during the 7 dit-length word space?  Do you need to
> > > have keyers that extend the word-space period?  I
> > > think it is unlikely a rig that is busy doing all this
> > > signal processing is going to ever be as good a QSK
> > > radio as my old 580 delta in therms of "breakin".
> > > Maybe if there were separate receive and transmit DSP,
> > > maybe if you had parallel co-processed transmitter and
> > > receiver so thing were not being done serially, you
> > > could approximate the behavior of the 580 delta.
> > >
> > > You may call these "bells and whistles" but it is
> > > merely an engineering design trade-off between
> > > mutually exclusive criteria.  You can't receive
> > > processed audio until processing is completed, and if
> > > the rate of data transmission is faster this
> > > processing can occur in a given system, you won't be
> > > hearing any breaks.  Like I said I used to judge a
> > > radio by its QSK behavior.  But then I found QSK to
> > > not be as totally useful as I once thought.  Really
> > > fast well executed semi-breakin does just as well in
> > > my opinion.
> > >
> > > 73  W9OY
> > >
> > >
> > >
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