[CQ-Contest] Contesting and the FT8 Revolution

David Gilbert ab7echo at gmail.com
Mon Jun 21 18:43:02 EDT 2021

It would be interesting to know just how many db is lost due to 
asynchronous decoding, but let's say it's a lot and synchronous decoding 
is required.  That would be a minor sacrifice and everything else I have 
postulated should still be possible.  If the bandwidth was wide enough 
(and I think 200 Hz would be sufficient) the bit rates could be high 
enough with reasonable length data blocks to make it fairly transparent 
to the user.  Counting reaction time, it takes about five seconds to 
send "N4OGW 5NN AZ" via CW at 35 WPM.  I'm pretty sure a 
clock-synchronized digital format similar to FT8/FT4 with a 200 Hz 
bandwidth could be effective with a five second data block.

The major point is to break free of WSJT-X's fixed window and fixed 
message format, and apply as much of the signal processing as possible 
to a spin the dial format ... with, in my opinion, a human involvement 
(which is why I've suggested a conversion to audible CW on the receive 
end) if we want to make a contest out of it.  I'm convinced that can be 
done ... it just won't ever be done by K1JT.

Dave   AB7E

On 6/21/2021 1:33 PM, RT Clay wrote:
> The weak signal performance of FT-8 is in a large part due to its time synchronization, which is part of the specification of FT-8, not a "limitation" of wsjtx. With an asychronous digital mode the decoder has to figure out when a transmission starts. For weak signals that is a very hard problem. The same weak signal performance is NOT possible without the synchronization.
> FT-8 and FT-4 are lousy contest modes because when signals are strong they are too slow, and they can't adapt to signal strength like CW or SSB can. FT-8 has majorly impacted VHF contesting. Now many op's 6m radios are stuck on 50.313 FT-8 and many have disconnected microphones. 6m Es is however not always a weak signal mode, and in a strong opening FT-8 is simply too slow comapred to SSB. FT-4 is a partial solution but nobody wants to leave 50.313 FT-8.
> A better way would be to run FT-8 and FT-4 on the same channel and have wsjtx decode both at the same time.
> Tor N4OGW
>     On Monday, June 21, 2021, 2:52:27 PM CDT, 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.
> 2.  fully tunable over the typical digital sub band (like RTTY does)
> 3.  Asynchronous in time ... i.e., not locked to a discrete and specific
> clock window
> 4.  shorter blocks of data with continuous feed of the blocks
> 5.  sent via text blocks on the transmit end ... exactly as DVRs and
> contest loggers do now
> 6.  displayed as text or converted to audible CW (or even digital voice)
> on the receive end
> Such an interface would be amenable to DXing, contesting, or ragchewing
> with a user experience similar to CW or RTTY, except with far better
> weak signal performance.  It would even be possible to have a built in
> CW to text converter on the transmit end for CW ragchewing.  In my
> opinion, it's almost a crime that the capability of FT8/FT4 is being so
> completely constrained by WSJT-X.
> The weak signal performance of FT8/4 is entirely possible with a user
> interface that would be hard to distinguish between how we typically use
> CW and RTTY for DXing and contesting.  I've dug into this stuff enough
> to know that (and I have a son who has done leading edge work on this
> kind of thing for a living for over 20 years) ... I'm just not smart
> enough to code it.
> 73,
> Dave   AB7E
> On 6/20/2021 10:54 PM, Jeff Blaine wrote:
>> This point that Ted makes - the FUN aspect - is in my opinion why
>> FT8/FT4 contesting struggles.
>> Yes, it's fun to make FT8/FT4 contacts initially.  And the underlying
>> technology is about as cool as it possibly gets.  But from a
>> competitive standpoint, once the novelty wears off, it pretty quickly
>> becomes monotonous because there is no significant operator
>> intervention possible to push the rate or the mults higher.
>> A competitive game (which is really the essence of radiosport, under a
>> different term) which is going to drive increased and sustained
>> participation must have a method that provides an increased challenge
>> and a performance-based reward mechanism which is the payback for the
>> increased skill.  Unfortunately in FT8/FT4 the computer (and the
>> mode's structure) controls virtually all normal contest skill set,
>> save for picking the right band.  I'm generalizing here, but
>> essentially that's it.  One can go from an new FT8/FT4 contester -->
>> to an experienced one in about an hour or few.  And after that, almost
>> nothing you do with respect to operation will significantly affect
>> your results.  The variables are limited, with perhaps the band chosen
>> being the most significant pick.  Otherwise, it's mostly up to the
>> computer.
>> Of course that depends on how the contest is setup.  Some formats make
>> more sense to me than others.  I've always thought the grid-square
>> based mileage method popularized by the RTTY Makrothon and CW/SSB Stew
>> Perry contests provided a format that was almost ideal for the FT8/FT4
>> mode.  It provides a about as close to an even playing field with
>> respect to location as you are going to get in radiosport.  And it's
>> fun to watch what grid square pops up with each new caller as that
>> drives a variable points count.
>> Unfortunately, even with a complementary contest format like mentioned
>> above, the operator performance reward is absent once you get the hang
>> of it, and it's that aspect of the mode that puts an upper limit as to
>> the "fun" realizable.
>> 73/jeff/ac0c
>> alpha-charlie-zero-charlie
>> www.ac0c.com
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/cq-contest
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/cq-contest

More information about the CQ-Contest mailing list