3000km+ opening on 144 MHz in Europe - 28th May 2025

On the 28th of May 2025, there was a Sporadic-E opening in Europe on the 144 MHz band. While single hop Sporadic-E openings are of interest to the individuals concerned, the interesting paths are the really long distance ones that can't be so easily explained.

The maximum distance for one hop Sporadic-E is about 2300kms although this can be extended somewhat at either end by tropo. The paths shown above are for those that are over 2800kms with eight over the 3000km mark.

It's very likely that these were double hop Sporadic-E. This requires two separate areas in the E-layer of the ionosphere which support propagation at 144 MHz. One area is unusual but it's a lot rarer to get two areas at the correct distance apart at the same time.

The list of stations over 2700kms is shown below...

UTC Date/Time Spotter QRG Mode DX                                         km Text
2025-05-28 15:46:00 G4PEM (IO70IE) 144.176 FT8 RY6N (KN97VG) 3270 IO70ie KN97 FT8 +11
2025-05-28 15:47:00 RY6N (KN97VG) 144.176 FT8 G4LOH (IO70JC) 3266 KN97vg IO70 FT8 +20
2025-05-28 15:50:09 G4RRA (IO80BS) 144.174 FT8 RY6N (KN97VG) 3159 IO80BS ES KN97VG
2025-05-28 15:52:39 G4RRA (IO80BS) 144.174 FT8 UA6LJV (KN97LE) 3105 IO80BS ES KN97LE seen
2025-05-28 15:58:33 F6DBI (IN88IJ) 144.174 FT8 RN3QR (LO00BK) 3102 IN88IJ ES LO00BK TKS
2025-05-28 15:56:00 F6EGD (IN88HR) 144.175 FT8 RN3QR (LO00BK) 3095 IN88hr LO00 FT8 -12
2025-05-28 15:52:03 GW7SMV (IO81LO) 144.174 FT8 R6CS (KN95BW) 3038  ES FT8 +0 dB 2165 Hz hrd
2025-05-28 15:49:52 G4RRA (IO80BS) 144.174 FT8 R6OH (KN97CW) 3021 IO80BS ES KN97CW
2025-05-28 15:52:07 G4RRA (IO80BS) 144.174 FT8 RA6O (KN87UX) 2985 IO80BS ES KN87UX seen
2025-05-28 15:53:00 UR7IMM (KN88TR) 144.175 FT8 F6EGD (IN88HR) 2969 KN88tr IN88 FT8 -18
2025-05-28 15:46:00 RY6N (KN97VG) 144.175 FT8 M0CFO (IO90) 2961 KN97vg IO90 FT8 -02
2025-05-28 15:46:14 G4DCV (IO91OF) 144.174 FT8 RY6N (KN97VG) 2938 IO91 ES KN97 73
2025-05-28 15:54:54 F6DBI (IN88IJ) 144.174 FT8 UT7LK (KN89BW) 2836 IN88IJ ES KN89BW TKS
2025-05-28 15:56:10 G4RRA (IO80BS) 144.174 FT8 US5EII (KN78JK) 2765 IO80BS ES KN78JK seen

Propagation Mode?... While it seems likely that there were two hops involved, it's open to debate whether the signals bounced off the ground mid-path or whether there was some chordal hop as shown in the example above.

Trans-Atlantic?... The distance from Ireland to Newfoundland is about 3000kms. Looking at the distance of the East-West paths on the 28th of May, the question is if a similar path might exist at times on 144 MHz across the North Atlantic?

Link... For more examples of long distance 2m paths, see my 144 MHz page.

Addendum: 

Additional info from Tim, G4LOH (IO70JC) in the SW of England.
1kW into 4 x 16ele
Log:
15:42 RY6N KN97vg 3270km
15:45 R6OH KN97cw 3132km
15:46 RA6O KN87ux 3095km
15:46 US5EII KN78jk 2876km
15:47 RK6MF KN97rc 3253km
15:48 RK7N KN97kg 3206km
15:49 UA6LJV KN97le 3215km
15:50 UR7IMM KN88tr 3061km
16:10 SP8WW KN19fm
16:12 SP8WJW KN09sr
Comment: An interesting chordal hop opening. I saw 3 stations in Russia and 5 others in Eastern Ukraine, followed by two more in South East Poland, all FT8.  One complete QSO, the others were heard loud for ~10 minutes, pure chordal hop. The SP stations were seen a few minutes after the chordal opening ended.

Dutch radio amateurs bounce 1299 MHz microwave signals off the planet Venus

On the 22nd of March 2025, a group of Dutch radio amateurs managed to successfully bounce a 23cms microwave signal off the planet Venus using the 25-metre Dwingeloo telescope.

At the time, Venus at the time was at its closest point to Earth with a distance of 42-million kilmetres. This happens approximately every 580 days which is about a year and seven months.

For the test, they used a 278 second long tone at a frequency of 1299.5 MHz. The return path from the Earth to Venus and back was about 280 seconds which is 4 minutes and 40 seconds. They repeated this cycle four times and a sample of the returned signal is shown below.

The test transmissions were also heard by another group using the 25m Stockert radio telescope in Germany.

They hope to resume their Earth-Venus-Earth (EVE) at the next closest approach in October of 2026.

Link... https://www.camras.nl/en/blog/2025/first-venus-bounce-with-the-dwingeloo-telescope/

FOSDEM 2025 in Brussels -- HAMNET, M17 & MESHTASTIC presentations

FOSDEM is a free event for software developers from all over Europe to meet, share ideas and collaborate and it held this year in Brussels on the 1st & 2nd of February 2025.

Out of the 1000+ lectures, a few were radio related...

Saturday - 1st Feb 2025
Using AI hardware accelerators for real-time DSP on embedded devices - NPU, TPU etc,
M17 and OpenRTX: one year later
The AFF3CT framework for building numerical communication chains
HAMNET - Status Update
RF Swift: A Swifty Toolbox for All Wireless Assessments
SDR++, a modular, cross-platform SDR utility
Broadband data transfer over USB for GNU/Linux: 1-2 GHz (L-band) SDR receiver
Meshtastic - off-grid communication for everyone
Yet another new SDR runtime?

Some of these talks have slides available in PDF format and there are links if you want to explore the subject more.

The links to each radio talk can be found here... https://fosdem.org/2025/schedule/track/radio/

Here are three subjects that I found of interest.

1) HAMNET... 

HAMNET is a Highspeed Amateur Radio Multimedia NETwork developed from an experiment into a stable infrastructure, particularly in German-speaking countries. It generally connects unmanned amateur radio stations via microwave links using the IPv4 and BGP protocols and provides a platform for networking amateur radio applications.

The slides for this talk can be found HERE

2) M17...

M17 is an open source protocol for digital radio and its goal is to allow radio amateurs to communicate via digital voice and data. The M17 team are also developing open source hardware in conjunction with this. The net result is to have hardware and software that is designed for the amateur radio community and is not dependant on commercial companies or third parties. In other words, M17 is designed by radio amateurs for radio amateurs.

The slides for this talk are HERE

3) Meshtastic...

Meshtatsc is described as follows... "Meshtastic is an open source, off-grid, decentralized, mesh network built to run on affordable, low-power devices.  It uses Lora-P2P with dedicated radio chips and forms ad-hoc meshes. In HAM mode the encryption is switched off and the ISM airtime restrictions are lifted."

Meshtastic goes beyond the confines of the amateur radio bands and allows anyone with an interest in electronics to experiment on the UHF licence free ISM radio bands like 868 MHz in Europe and 915 MHz in North America. Radio amateurs have the ability to use higher power on bands like 433 MHz.

More links can be found HERE

Notice: Upcoming HAARP ionospheric tests from Alaska - 27th to 31st Jan 2025

High-frequency Active Auroral Research Program (HAARP) is based in Alaska and it's a high-power, high frequency (HF) transmitter for studying the ionosphere.  The principal instrument is a phased array of 180 HF crossed-dipole antennas  capable of radiating 3.6 megawatts  into the upper atmosphere and ionosphere.  Transmit frequencies are selectable in the range of 2.7 to 10 MHz.

Update: Note that due to hazardous winter road conditions along the highways leading to the HAARP facility, the January Research Campaign has been delayed by 1 day. Dates updated below.

The research team have announced that they will be carrying out tests from the 28th of January to the 2nd of February 2025.

The press release is shown below and I've added a map to show location and distance.

To: Amateur Radio & Radio Astronomy Communities

From: HAARP Program Office

Subject: Notice of Transmission

The High-frequency Active Auroral Research Program (HAARP) will be conducting a research

campaign with operating times specified in the table below. Operating

frequencies will vary, but all HAARP transmissions will be between 2.75 MHz and 10 MHz. Actual

transmit days and times are highly variable based on real-time ionospheric and/or geomagnetic

conditions. All information is subject to change.

This campaign is being conducted in support of research proposals from UAF, the University of

Florida, the Naval Research Laboratory, Los Alamos National Laboratory, Cornell University,

Dartmouth College, Embry-Riddle Aeronautical University, and the University of Houston.

Research topics for this campaign include VLF generation and ducting, studies on STEVE airglow,

and space debris detection. 

This campaign will also support the GIRAFF rocket launch from Poker

Flat Research Range, which is investigating the mechanisms that cause flickering and pulsing

within the aurora. More information on GIRAFF is available here:

https://sites.wff.nasa.gov/code810/news/story301-36.380%20381%20GIRAFF.html

Note that a number of experiments will be conducted based on the critical frequency (f0F2)

determined by the Gakona ionosonde. The included transmission notice supplement contains

information on the frequencies HAARP is authorized to transmit. HAARP transmissions will only

occur on our authorized frequencies. 

There are no specific data collection requests from funded investigators, but reception reports are appreciated and may be submitted online via our web form

at: https://haarp.gi.alaska.edu/form/reception-reports

For updates on ionospheric conditions in Gakona, please consult ionograms from the HAARP

Diagnostic Suite: https://haarp.gi.alaska.edu/diagnostic-suite

Additional Resources for Reading Ionograms
Understanding HF Propagation and Reading Ionograms from Bootstrap Workbench:
https://www.youtube.com/watch?v=oTFKNCo3Cl8

Reading Your Ionogram-Keeping It Simple from John (VE6EY):
https://play.fallows.ca/wp/radio/shortwave-radio/reading-your-ionogram-keeping-it-simple/

The image above is an annotated ionogram from HAARP that describes features that may be of

interest. Note that f0F2 is calculated at the top left.

f0F2 is the critical frequency of the F2 layer of the Earth’s ionosphere. This is the frequency at
which radio signals stop refracting off the ionosphere and begin passing through to outer space.
For certain HAARP experiments that deal with interactions in the ionosphere, transmission
frequencies below f0F2 are desirable, while for other experiments (such as those involving high altitude satellites), staying above f0F2 is required.

Supplement to HAARP Notice of Transmission

General Information for HAARP Radio Enthusiasts:

Notice: 145 MHz Activity Period for the UK & Ireland - Sun 26th Jan 2025

The 145 Alive Group are organising an activity period on the 2m amateur radio band in the UK & Ireland on Sunday the 26th of January 2025 from 12:00 to 15:00 UTC.

This is not a contest and the aim is to promote more activity on the 2m amateur radio band. The approximate location of the net controllers are shown in the map above and they will be operating on the FM channels from 145.250 to 145.575 MHz.

Don't worry about who is operating where, just tune around and see who you can hear. All you need to do is to call in and give a report. If you listen for a few minutes, you'll get the format of the exchanges.

The weather isn't looking great with a named storm crossing over the UK & Ireland on Sunday. This may result is fewer stations taking to high ground.