Hi Paul,
Any progress? Anybody answered in 30 minutes?
K2BB
On Wed, Jun 27, 2012 at 8:39 PM, Paul Stoetzer <n8hm@arrl.net> wrote:
> Anybody want to try ASCII? I've never made a QSO. I'm calling CQ at
> 14.088.5 MHz.
>
> Paul, N8HM
>
> On 6/27/2012 8:33 PM, Robert Chudek - K0RC wrote:
> > The *BARTG High Speed Sprint* might be an existing (recently introduced)
> > contest to make the transition?
> >
> > 73 de Bob - KØRC in MN
> >
> > ------------------------------------------------------------------------
> > On 6/27/2012 3:43 PM, Paul Stoetzer wrote:
> >> Somebody should set up an ASCII contest. That would be interesting.
> >>
> >> Paul, N8HM
> >>
> >> On Wed, Jun 27, 2012 at 4:36 PM, Kok Chen <chen@mac.com> wrote:
> >>> On Jun 27, 2012, at 12:47 PM, Alex Malyava wrote:
> >>>
> >>>> Why don't we just invent/introduce some new RTTY standard -
> >>>> the one with 6 bits instead of 5 - covering whole alphabet and digits
> >>>> without any FIGS/LTRS and speed it up a little bit to compensate an
> extra
> >>>> bit?
> >>> There is no need to introduce another "mode du jour" even.
> >>>
> >>> 7-bit ASCII (CCITT ITA-5) RTTY has been FCC approved (see part
> 97.309(c)) for a long time now. fldigi supports it, so does MultiPSK and
> cocoaModem, among others.
> >>>
> >>> In a discussion (a year or even longer ago) on this reflector, I had
> shown that for most RTTY contest exchanges, ASCII RTTY beats out Baudot
> RTTY in speed, even when both are running 45.45 baud.
> >>>
> >>> You get rid of the FIGS/LTRS confusion (thus problem with USOS
> incompatibility either; USOS is a Baudot problem), allows lower case, and
> it still beats out Baudot in contesting speed. It is when sending
> paragraphs of upper case text that Baudot wins over ASCII.
> >>>
> >>> Because of the Teletype Models 33/35, the popular speeds for running
> ASCII RTTY was 110 baud. At that speed, it will wipe the floor with Baudot
> RTTY.
> >>>
> >>>> Or drop one stop bit to save the length? Or use 3 frequency FSK -
> >>>> shift left is "0", shift right is "1" and middle is sync/start/stop ?
> >>> 3FSK may not be a good idea. The reason is that the equalizer to
> compensate for selective fading will be at best very complex to build.
> >>>
> >>> 2FSK has the very unique ability to fight selective fading with a very
> simple thresholding scheme. Once you add more tones, you can no longer
> build simple ATC circuits.
> >>>
> >>> For that reason, you will find that there is nothing in MFSK16 (16
> tones), DominoEX (18 tones) or Olivia that explicitly fixes the selective
> fade problem -- they all use long interleaved codes to fight QSB in general
> -- and you may not want to use long interleavers with short contest
> exchanges; the latency will need to be over 1 second to be effective. You
> will need to add latency to the exchange time. Selective fading happens
> quite often. You can almost not avoid it with a Rayleigh path.
> >>>
> >>> Anyhow, the solution is already at your fingertips, and the FCC has
> blessed it for years now. It is called ASCII. And 110 baud with 170 Hz
> shift is a breeze.
> >>>
> >>> 73
> >>> Chen, W7AY
> >>>
> >>>
> >>>
> >>>
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> >>
> >
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>
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