[CQ-Contest] WW-Digi Contest -- Rule Clarification

David Gilbert xdavid at cis-broadband.com
Wed Aug 7 12:46:17 EDT 2019


Well, the WWROF just created what they hope is a 4th CQWW major contest, 
the WW-Digi contest, and they've been publicizing it heavily here on the 
reflector with webinar and practice session announcements.  If they 
don't mess it up it is likely to be fairly popular for the following 
reasons:

1.  It is weak signal so contacts that might not otherwise be possible 
will be available, making the available pool of points and multipliers 
greater, especially with the current lack of sunspots.

2.  Big signals don't necessarily dominate.  A +10 signal and a -15 
signal both show up equally in the activity window.  That's appealing to 
hams with lesser stations or who live in propagation-challenged locations.

3.  WSJT-X offers a sort of native pileup management in a structured 
format.  Casual contesters who might be hesitant to run a frequency on 
CW or SSB have relatively little downside to doing so in FT8 or FT4, 
which again should be appealing to them.  They just click on the next 
callsign.

My station isn't terrible and I'm not afraid to run, so for me the 
interesting aspect will be to explore how to optimize runrates.  I'd 
classify myself as being more curious than excited at this point, but I 
have to admit to being pretty curious.  I suspect that people smarter 
and more creative than I am are going to come up with ways to turn FT4 
into a pretty hectic activity by juggling overlapping contacts and 
coming up with ways to use multiple simultaneous streams that don't 
pollute with IMD.

I agree that FT8 can get boring, but a contest with a lot of interest is 
still a contest and I haven't seen any list guidelines here that try to 
put a cap on related discussions based upon mode.

73,
Dave   AB7E


On 8/7/2019 7:50 AM, Jeff Clarke wrote:
> Didn't someone create a FT8 contest reflector? It would be nice to 
> take all these comments over there. Seems like FT8 is monopolizing the 
> contest reflector just like it is on the air.
>
> Seems like the last two big Dxpeditions (CY9 and 3D2) are putting FT8 
> first before the traditional CW/SSB modes. I sure hope this isn't the 
> future of ham radio.
>
> BTW I do operate some FT8 because I'm working on a the digital DXCC. 
> (because there is hardly any RTTY activity outside of contests) Now 
> that I've reached 100 countries I'm starting to get bored with it.
>
> Jeff
>
> On 8/7/2019 04:31 AM, David Gilbert wrote:
>> Then why don't the WW-Digi rules simply state that such operation 
>> (multiple QSOs on the same band using Fox/Hound mode) is not 
>> allowed.  Most contesters are NOT going to be aware of, or maybe not 
>> even care about, any splatter caused by their own operations. Most 
>> FT8/4 operators have no easy means of monitoring their own transmit 
>> quality, and that should be obvious from watching the spectrum 
>> display at almost any time of day or night.
>>
>> Expecting participants in the contest to understand that they 
>> shouldn't use Fox/Hound based upon the webinar doesn't make much 
>> sense.  You'd be lucky if a third of the participants in the contest 
>> even watched the webinar.  They're going to (hopefully) go by the 
>> written rules, which currently do not specifically outlaw multiple 
>> simultaneous signals, and that means that people familiar with 
>> Fox/Hound mode are going to be inclined to use it.  You specifically 
>> say below that multiple parallel QSOs WOULD be OK if they didn't use 
>> Fox/Hound to achieve it ... so why don't your rules simply say that?
>>
>> I disagree that Fox/Hound is the only way to transmit multiple 
>> signals at the same time.  I'm pretty certain I could do it with 
>> multiple rigs and running multiple instances of WSJT-X (which WSJT-X 
>> allows) on the same computer.  All it would require is different com 
>> ports and rig assignments for each instance of WSJT-X, and the 
>> outputs would be independent and therefore clean barring any 
>> nonlinear combining of RF past the rigs.
>>
>> I just don't understand why you don't write the rules to clearly 
>> prohibit that which you don't want to happen.  It's like you're 
>> posting a DO NOT ENTER sign on the back door of the building.
>>
>> 73,
>> Dave   AB7E
>>
>>
>>
>> On 8/6/2019 8:48 PM, Ed Muns wrote:
>>> This is an example of the DXpedition "Fox and Hound" mode where the 
>>> DXpedition station is the Fox and transmits 2-5 distinct audio 
>>> frequencies within his TX passband using a single suppressed carrier 
>>> at the radio dial frequency.
>>>
>>> The WW Digi rules are written to allow multiple parallel QSOs. This 
>>> is appropriate for this narrow-band multi-channel signal 
>>> technology.  As of today,  the only technique I'm aware of for 
>>> achieving this is the Fox and Hound mode described above. However, 
>>> in a multiple-Fox scenario like contesting, this method of parallel 
>>> QSOs is unacceptable.
>>>
>>> The reason is that two or more audio signals are effectively 
>>> transmitting a Two-Tone (or Multi-Tone) IMD test on the band. The 
>>> narrow, vertical-skirt FT signals are thereby turned into wide, 
>>> flared-skirt signals that will QRM neighboring QSOs on both sides.  
>>> In the DXpedition scenario with just one Fox, that IMD can be 
>>> contained in a small area of the pass band, say 400-500 Hz, while 
>>> all the DXers (Hounds) calling in can spread out in the rest of the 
>>> passband.
>>>
>>> In a contest scenario where there will be many Foxes, all trying to 
>>> increase their QSO rate, the FT sub-band will be wall-to-wall IMD 
>>> QRM.  This is a flagrant betrayal of the exceptional signal design 
>>> in the basic FT GFSK signal. Not to mention unsportsmanlike 
>>> operating in general.
>>>
>>> Therefore, the pertinent WW Digi rule is:
>>>
>>> XII.A.5. Poor signal quality that interferes with other stations’ 
>>> ability to operate. This includes, but is not limited to: signals 
>>> with excessive bandwidth (e.g., splatter, clicks, IMD), harmonics on 
>>> other bands, and excessive audio levels.
>>>
>>> One purpose of this rule is to rule out the current Fox and Hound 
>>> method in WW Digi, among other signal quality issues like 
>>> overdriving the TX audio.  It is easy to spot parallel QSOs in a log 
>>> and any such cases will be reviewed with SDR recordings. Don't use 
>>> the current Fox and Hound implementation in this or any other 
>>> contest.  Some of the software packages don't allow Fox and Hound 
>>> mode when the contest mode is selected, to help participants follow 
>>> the rules.
>>>
>>> The WWROF webinar the past Sunday, replayed Monday evening NA time, 
>>> explained this with spectrum images of clean and ugly FT signals.  
>>> The presentation PDF is linked from the WW Digi home page, and the 
>>> webinar video recording will be linked there and on the WWROF 
>>> webinar archive page later this week.
>>>
>>> Ed W0YK
>>>
>>> -----Original Message-----
>>> From: CQ-Contest <cq-contest-bounces at contesting.com> On Behalf Of 
>>> David Gilbert
>>> Sent: 06 August, 2019 12:10
>>> To: 'CQ-Contest at contesting. com' <cq-contest at contesting.com>
>>> Subject: [CQ-Contest] WW-Digi Contest -- Rule Clarification
>>>
>>>
>>> Although it is certainly implied, the rules listed on the WW-Digi
>>> website do not specifically prohibit using more than one signal at the
>>> same time ON THE SAME BAND for the single op category.  They say that
>>> transmission can only be on one band at a time, but they don't say you
>>> can't make multiple transmissions at the same time on the same band.
>>>
>>> The reason I bring this up is that I just witnessed 5T5PA making three
>>> separate FT8 transmissions on 20m to three different stations all 
>>> within
>>> the same fifteen second window.  A short time later I saw two separate
>>> transmissions from him to two different stations (and different 
>>> stations
>>> than the previous three), again all within the same fifteen second
>>> window.  Each simultaneous transmission was spaced exactly 60 Hz apart,
>>> and the software cleanly decoded all signals as if they were from
>>> different callsigns.  5T5PA expertly managed all the QSOs cleanly.
>>>
>>> Interestingly enough, even though I've worked 5T5PA before, JTAlert 
>>> only
>>> labeled one of the three as a dupe.
>>>
>>> I can think of more than a couple of ways 5T5PA could be doing this, 
>>> and
>>> for casual operation I see no problem with it.  For a DXpedition, it
>>> might even make a lot of sense.  I don't remember it being against
>>> FCC/other laws, but I could be wrong about that.  In any case, it seems
>>> to me that it could open up the possibility for some controversy in a
>>> contest.
>>>
>>> Or maybe I'm just crying wolf here ...
>>>
>>> 73,
>>> Dave   AB7E
>>>
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>>>
>>
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