Why all the fuzz about the OZ-EA8 QSO july 12. 2020 144MHz?

On the OK2KKW board some amateurs discuss the validity of the qso done between me and EA8CXN.

I dont see why all this discussion and making any doubt about the record.

It has been done before, and i was there at the spot in the right time and place.

Timeframe from 19:50 to 19:55. Signals both ways where so strong we could easily have worked ssb/cw as well.

JTDX gives far less RX report than WSJT-X, which explains the difference in the two signal reports.
If you compare the station OZ9GA only visible by 10dB in JTDX, in WSJT-X he would be +20dB or even higher.
This is without any end result of the actual decode, the dB listing is simply just lower.
At least in the rc.-151 version i used at the time of the record.
I totally agree with EI7GL, the tropo part of the path accounted for 1500kms to Portugal/Spain area and the remaining 2200kms was Sporadic-E.

End of discussion.

The discussion came on the background of this article done by EI7GL :

https://ei7gl.blogspot.com/2020/08/144-mhz-contact-between-denmark-canary.html

Thursday, August 27, 2020

144 MHz contact between Denmark & the Canary Islands exceeds 3000kms

Long distance contacts on 144 MHz that are in the region of 3000kms are always of interest as that is the distance across the North Atlantic between Ireland and Newfoundland. In this series of blog posts, I will look back at some of the 3000km plus contacts on 144 MHz during the Summer of 2020 that I haven’t reported on yet.

Back on the 12th of July 2020, there was a remarkable contact made on FT8 on 144 MHz between EA8CXN in the Canary Islands and OV3T in Denmark at about 19:55 UTC.

OV3T in Denmark was using 400 watts into a 10-element Yagi for the contact. I’m not sure what EA8CXN was using.
EA8CXN gave OV3T a report of +8dB while OV3T gave EA8CXN a report of -10dB. This probably meant that CW or FT8 were the only viable modes for making a contact.
Mode of Propagation… The distance was in the region of 3710 kms which is well in excess of the usual 2300km limit for one hop Sporadic-E. So what is the likely explanation?
First off, we can look at the Hepburn prediction map for tropo for the day…

If you examine the right hand side of the map, it shows an enhanced maritime duct from the Canary Islands (EA8) to Spain and Portugal. This tropo path was confirmed earlier on the 12th when EB1DJ spotted EA8CXN on the DX  Cluster.
EB1DJ 144174 EA8CXN 10:30 13 Jul 20  TR  FT8 +4 dB 863 Hz Canary Islands

While OV3T was working EA8CXN at 19:55 UTC, another Danish station OZ1CCM worked EA1YV at about the same time which suggests a short Sporadic-E opening from Denmark to NW Spain & N Portugal.

While we can never be 100% sure of what exactly happened, this is the likely scenario….

There was an marine duct from the Canary Islands to the west coast of Spain and Portugal for most of the day. This maritime duct probably didn’t get more than 100kms inland and probably didn’t cross over the mountains on the Iberian peninsula.

At about 19:50 UTC, there was a short Sporadic-E opening from Denmark to NW Spain & N Portugal. The Sporadic-E signals from Denmark got coupled into the marine duct and on to the Canary Islands.

The tropo part of the path probably accounted for 1500kms of the total while the remaining 2200kms was Sporadic-E.

In conclusion… This contact yet again shows the value of the FT8 digital mode in exposing propagation paths that we didn’t know were possible. 

It also shows the paradox of FT8… i.e. The problem with FT8 is that it is overcrowded because there are too many on the one frequency but it’s because there are so many on the same frequency that there is a better chance of catching unusual openings.

The opening from Denmark to the Canary Islands also raises the possibility of a further extension further south to the Cape Verde Islands. The maritime duct off the west coast of Africa often extends from Cape Verde to Spain and Portugal and if that coincided with a similar Sporadic-E opening again then perhaps contacts in the region of 5,200kms might be possible.Links…1) OV3T blog post2) EA8CXN blog post3) VUSHF post in Danish

4 meninger om “Why all the fuzz about the OZ-EA8 QSO july 12. 2020 144MHz?

  • 2. september 2020 kl. 1:52
    Permalink

    Hi Thomas,

    QSO is completely real, just few answer to some questions:
    – My signal Report for you was +8. You give me -10. It is totally normal, I use a Yaesu FT-991, with DNR at full , and usually I give better reports that I receive. For example, I can listen one station without DNR at -10 , and with DNR on +16. I made several test regarding this good equipment for FT8 and other digital modes.

    – The only possibility was FT8. The conditions was only few seconds, after QSO, the conditions dissapear, so no chance to switch to SSB ( I do not use CW).

    – It is a combination of Tropo+ES. It is totally normal to work France, Belgium, Netherlands on 144Mhz with Tropo untill EA1 and further on ES. Many QSO happen like that.

    QSO is totally real, screenshots are there and PSKreporter also.

    Last week I perform transatlantic QSO from EA8 to Caribean. 4800+ Km on SSB and 5200+ Km on FT8 during 2 days. So distance of 3000Km is not new. These QSO were possible due to FT8 and PSKreporter because we know that the duct is open, and further signal analysis to complete on SSB, see screenshots and videos on https://ea8cxn.es/?p=258

    For shure, not metteors are involved in our QSOs

    Best Regards! and hope to see you again on my waterfall Thomas!
    73, EA8CXN

    Besvar
  • 2. september 2020 kl. 16:04
    Permalink

    ok1vpz
    2. 09. 2020, 12:39:31 z adresy: 193.84.96.13 – 193.84.96.13

    Thomas, thanks for clarification. Nobody says, that your DX is a fake QSO. No. Part of my text just put the question, why not use human modes, like CW instead of FT8, when it is possible and it resulted with suspection that it is not only operator unability use the telegraphy, but as well as because it could be QSO made just between machines, when operator (operators) are away. And on the end my sigh, that ham radio community still waiting for IARU decision, if pure machines QSO without operator presence can be consider as valid. Its really shame, when you didn’t repeated it in “human mode” when it was so easy. Such record QSO then will be famous. Let me wish you for final many good DX contacts – better just with computer assistance, but not alone made by your computer only. Thanks for understanding. 73, Vlada.

    Besvar
  • 3. september 2020 kl. 11:53
    Permalink

    Do not take OK1VPZ and OK1TEH seriously. Both are trolls and the OK HAM community has not taken them for a long time and laughs at them.

    Besvar
    • 3. september 2020 kl. 16:21
      Permalink

      Typical attack of one CB “expert”. LOL!

      Besvar

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