Showing posts with label G4RRA. Show all posts
Showing posts with label G4RRA. Show all posts

Saturday, March 13, 2021

Example of a 3600km+ opening on 144 MHz from Ireland to Russia - June 2020

I'm always interested to hear about exceptional VHF contacts or reception reports and I like to keep a record of them here on the blog to encourage more people to get active on the bands. I meant to put up this post months ago but it kind of got delayed! 😄

Back on the 16th of June 2020, there was a Sporadic-E opening on 144 MHz over eastern Europe with stations in the south of Russia working into Poland and the Czech Republic. What was really unusual was that it coincided with another opening further west from the UK & Ireland to the Czech Republic, Poland and Ukraine.


The map above shows the signals that were heard by Mark, EI3KD on the 2m FT8 frequency of 144.174 MHz

This is a log extract of what EI3KD heard...

20200616_060700 -21 0.3 866 ~ CQ UC6A KN84
20200616_060730 -15 0.3 865 ~ CQ UC6A KN84
20200616_061200 -11 0.5 705 ~ CQ SQ9IVD KN09
20200616_061330 -14 0.2 1397 ~ EI3KD UX2SB -18
20200616_061330 -12 0.1 724 ~ YO6OBK UW8SM KN28
20200616_065200 -5 0.3 1562 ~ OE5JFL RZ6DD -18
20200616_065400 -19 0.2 1126 ~ CQ OK1VOF JN89
20200616_065430 -11 0.4 1800 ~ US5FZ RA6C -12
20200616_065430 -20 0.2 1126 ~ CQ OK1VOF JN89
20200616_065800 -22 0.0 1486 ~ CQ RX6DN KN94
20200616_065930 -26 0.1 1485 ~ EI3KD RX6DN R-07
20200616_070330 -11 0.3 1088 ~ CQ 9A2RI JN65
20200616_070400 -7 0.3 1089 ~ CQ 9A2RI JN65
20200616_070430 -22 0.2 1090 ~ CQ 9A2RI JN65


The normal maximum distance for single hop Sporadic-E is in the region of 2300 kms. What is highly unusual here is that EI3KD heard four stations in the south of Russia which were in the region of 3500kms!

The longest distance was RZ6DD at 3638kms.

The propagation mode was double hop Sporadic-E and this is clear from the fact that stations at the mid-way point were being heard as well. What's not so clear is if the signal was reflected off the ground at the half-way point or if it was chordal hop with the signal going between two Sp-E clouds without touching the ground. Whatever it was, it's an exceptional distance for 144 MHz.

This is an extract from DXMaps showing the DX-Cluster reports on that day on 144 MHz which were over 2500kms...


First a word of caution! As we all know, some mistakes occur with DX spots with people putting in the wrong band or info data. However, there are enough reports there to show that something special was going on that day.

You'll note that G4RRA in the SW of England also heard RZ6DD but at the slightly lower distance of 3356kms. See addendum below.

Why does this matter?... Because if someone in Ireland can hear a station in Russia on 144 MHz who is 3600+ kms to the east then why not across the North Atlantic to Newfoundland which is even closer at 3200kms?


Surely even if the chance of double hop Sporadic-E over the North Atlantic is incredibly small, there must be times when there are single hop Sporadic-E openings from either side with 1000kms of tropo making up the difference?

Wouldn't it be interesting to have a permanent online receiver based in Newfoundland with a beam pointing east and listening all of the time on 144 MHz? Stations in western Europe could then beam west and listen for their own signals online to see if the path is open. Or people could just log in and check if the receiver is hearing one of the Trans-Atlantic beacons?

At the moment, the North Atlantic path could open up on 144 MHz and nobody will ever know because there is no-one listening at the Canadian end.

Addendum: Thanks to Paul G4RRA for the following info...


Here's how my screen looked during that event. Both Mark and I are always looking out for events like this which are very rare indeed in my experience.


This was only the second one I've participated in in over 40 years, at least I managed a QSO in the first one !


R6DB also mentioned seeing me on KST chat.  ...de Paul, G4RRA