[CQ-Contest] Contesting and the FT8 Revolution

Sun Jul 4 06:33:57 EDT 2021

Hi guys,

<<< ... I was
intrigued by the possibility of using the weak signal capabilities of FT8
to convert data to audible CW and voice... >

In France, we have an expression that says :  "why keep it simple when you can make it complicated"...

73 de Dimitri F4DSK

Le 4 juil. 2021 à 03:21, à 03:21, Henry Pollock - K4TMC <kilo4tmc at gmail.com> a écrit:
>As a 69-year-old phone contester with limited time to devote to
>researching
>all of the other aspects of the ever-changing ham radio hobby, I was
>intrigued by the possibility of using the weak signal capabilities of
>FT8
>to convert data to audible CW and voice.
>
>About the same time this subject was being discussed here, I came
>across
>another tidbit on a totally non-contest group about the Barrett 4050
>which
>uses a digital system to enhance HF weak signal voice communications. 
>The
>YouTube video example was very impressive.  I now wonder if the Barrett
>digital system is using something like FT8.
>
>So, I am happy that this discussion has continued here.
>
>73,
>Henry -  K4TMC
>
>
>On Sat, Jul 3, 2021 at 2:11 PM Jeff Clarke <ku8e at ku8e.com> wrote:
>
>> Again for the umpteenth time... Why are people talking about this
>> subject on a CONTESTING reflector? Neither FT8 or FT4 are contesting
>> modes. I guess this is more proof that FT8 has totally taken over ham
>> radio? I guess people are really bored and can't help themselves?
>Hello
>> Mr Moderator can you please tell people to stop!
>>
>> Jeff
>>
>> On 7/2/2021 09:01 PM, David Gilbert wrote:
>> >
>> > I've gone through this stuff in detail with someone who knows far
>more
>> > about digital signal processing than either of us, and everything I
>> > said is possible with the exception that I will acknowledge that
>> > synchronous operation has advantages.  My postulation does NOT
>involve
>> > adhering to the FT8 or FT4 protocol as you seem to suggest below. 
>I
>> > proposed a mode similar to FT4 except wider bandwidth (which dose
>NOT
>> > necessarily degrade S/N as you claim) and a different set of other
>> > parameters ... plus conversion to CW instead of fixed text blocks
>> > simply to make it more adaptable to common contesting practice.
>> >
>> > I don't care what you say ... it can be done, but it's going to
>take
>> > somebody to work it up from scratch instead of trying to port FT8
>or
>> > FT4 to a different user interface.  Just about everything you said
>> > below is wrong simply because you're stuck in that mental trap.
>> >
>> > I will say again since nobody seems to get it ... FT8 and FT4 as
>> > implemented by WSJT-X are not some new invention that locks all
>other
>> > similar efforts into the same set of boundary conditions that K1JT
>> > chose.  K1JT made very clever use of modern signal processing to
>> > create FT8, FT4, and other similar modes but he chose a VERY
>> > restrictive set of boundary conditions in order to implement his
>own
>> > particular vision.  Those same modern signal processing techniques
>> > could be implemented with different boundary conditions to give ham
>> > radio (and in particular contesting) a much cleaner and more usable
>> > interface.  Go read K1JT's descriptions of what he did and what
>> > techniques he used, and if you then do a bit of searching you will
>> > find lots of technical discussions of those same methods applied in
>> > different ways to other tasks.  WSJT-X is unique, but the the
>science
>> > behind it is not.
>> >
>> > I know that I am flogging a dead horse here, but it frustrates the
>> > hell out of me to see the opportunity that is being squandered
>simply
>> > because the guy that came up with the first popular manifestation
>of
>> > modern signal processing had such a limited vision of what it
>should be.
>> >
>> > Dave   AB7E
>> >
>> >
>> >
>> > On 7/2/2021 10:39 AM, Bill Coleman wrote:
>> >>
>> >>> On Jun 21, 2021, at 2:59 PM, David Gilbert <ab7echo at gmail.com>
>wrote:
>> >>>
>> >>> Everything you just said there is the fault of WSJT-X as a user
>> >>> interface ... not FT8 or FT4 as a mode.  They are NOT the same
>> >>> thing.  WSJT-X is simply the narrow and restrictive vehicle by
>which
>> >>> we have been exposed to the exceptional weak signal capability of
>> >>> modern digital processing (forward error correcting, Costas array
>> >>> processing, etc).  We'd all be having a LOT more fun with a more
>> >>> open ended interface ... possibly with these parameters:
>> >>>
>> >>> 1.  wider individual signal bandwidth, such as maybe 200 Hz
>instead
>> >>> of 83 Hz.
>> >> A wider bandwidth would potentially decrease the sensitivity of
>the mod
>> >>
>> >>> 2.  fully tunable over the typical digital sub band (like RTTY
>does)
>> >> There’s absolutely nothing stopping you from running FT8 or FT4
>> >> anywhere in the digital sub-bands. You may not have many QSOs
>there,
>> >> but it is possible.
>> >>
>> >>> 3.  Asynchronous in time ... i.e., not locked to a discrete and
>> >>> specific clock window
>> >> This requirement is fundamentally incompatible to the way that FT8
>or
>> >> FT4 work. The fixed transmission / reception windows are clearly a
>> >> part of the mode.
>> >>
>> >>> 4.  shorter blocks of data with continuous feed of the blocks
>> >> Shorter blocks? The blocks today only convey 77 bits (BITS!) of
>> >> information. That’s right, it takes nominally 15 (or 7.5) seconds
>to
>> >> transmit 77 bits (BITS!) of information.
>> >>
>> >> And continuous blocks don’t work either.
>> >>
>> >>> 5.  sent via text blocks on the transmit end ... exactly as DVRs
>and
>> >>> contest loggers do now
>> >> Remember the 77 bits (BITS!) mentioned earlier? Each transmitted
>> >> block has a certain structure, and typically contains the two
>> >> callsigns (caller and callee) and a little bit of additional text.
>> >> There’s no much room for sending any random text, because there’s
>> >> only a few bits available to on each sent block.
>> >>
>> >>> 6.  displayed as text or converted to audible CW (or even digital
>> >>> voice) on the receive end
>> >> Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
>> >> Web: http://boringhamradiopart.blogspot.com
>> >> Quote: "Not within a thousand years will man ever fly!"
>> >>              -- Wilbur Wright, 1901
>> >>
>> >
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