DX Central - Summer of DX Challenge

 

SEDAP: The World’s Most Advanced Sporadic Es Data Analysis Dashboard for the FM DX Community

OR IMMEDIATE RELEASE

DX Central Unveils SEDAP: The World’s Most Advanced Sporadic Es Data Analysis Dashboard for the FM DX Community

MANDEVILLE, La. — April 29, 2026 — DX Central is proud to announce the official launch of version 2.0 of our popular Sporadic Es Data Analysis Project (SEDAP), a revolutionary, interactive intelligence dashboard designed to decode the mysteries of VHF propagation. Officially unlocking on Friday, May 1, 2026, at 7:45 PM CDT (0045 UTC May 2) at fmdxdata.com, SEDAP transforms nearly a decade of siloed radio loggings into a massive, cinematic data science suite, completely free of charge for the hobbyist and academic community.

Historically, analyzing Sporadic E (Es) propagation on the FM band has been an isolated effort, with individual DXers tracking their own localized season-over-season metrics and comparing notes with other DXers. SEDAP shatters that limitation by aggregating more than 95,000 North American FM broadcast logs and presenting them with brand new interactive visualizations to give DXers a whole new understanding of this elusive and magical propagation method.

"For years, our understanding of Sporadic E has been largely limited to individual observations," said Loyd Van Horn, founder of DX Central and creator of SEDAP. "By bringing all of this data together, we aren't just looking at spreadsheets anymore. SEDAP allows us to physically watch ionospheric clouds spawn, compress, and track across the continent in real-time. We can finally see what a typical season looks like on a macroscopic level."

Built on a Google Cloud BigQuery architecture, SEDAP boasts a sleek user interface featuring dynamic visualizations, including:

• The Es-Cloud Tracker: The newest and perhaps most exciting addition to the SEDAP dashboard.   The Es-Cloud Tracker is a cinematic, multi-day playback engine that maps the approximate geographic formation location of FM DX Sporadic Es ionization clouds over North America.  Openings can be “played” on a timelapse, allowing DXers to watch a simulation of the Es clouds as they develop, morph and transit throughout the day or a range of days.  

• Path Line Analysis:  In-depth analysis on the most common and productive paths to and from a DXer or station location.  Visually “see” the paths that evolved over the span of a day or date range.

• Frequency & MUF Forensics: An interactive "SDR Tuner" interface to interrogate large scale band yields, signal paths, and daily Maximum Usable Frequency (MUF) ceilings.

• Station & RDS Intelligence: Deep-dive forensics into the WTFDA station database, featuring PI-Code adoption maps, format/slogan correlation matrices, and gamified "Unheard Target" lists for US States and Counties.

• DXer Network Intelligence: Long-term seasonal performance audits and multiple normalized metrics to filter out observer bias as much as possible

“We have certainly seen a huge growth in the number of DXers both reporting receptions and the amount of receptions they are reporting thanks to improved technology and resources from SDRs to propagation monitoring through Rabbitears and the FM DX Webservers,” says Van Horn.  “So while we are not here to say one season was better than another, we can give DXers insights into Sporadic Es season that can help them strategize antenna placement and bearing, timing of monitoring, potential paths based on different periods within the season and a whole lot more. This is about improving our understanding of what happens when the ionosphere sends those FM signals back down to Earth.”

SEDAP makes no claim of ownership over the raw data presented, acting strictly as an analytical engine. The platform owes its immense capabilities to the unprecedented collaboration and public data provided by FMList.org, and the Worldwide TV-FM DX Association (WTFDA).

To protect the integrity of the database and respect the bandwidth of its data partners, SEDAP is strictly governed by a non-commercial usage policy. Automated scraping and commercial monetization are prohibited, but users are highly encouraged to explore, share, and cite the dashboard's findings.

The Sporadic Es Data Analysis Project will be accessible to the public beginning May 1, 2026. To access the dashboard, view the real-time launch countdown, or read the full data usage policy, visit fmdxdata.com.

About DX Central: Based in Mandeville, Louisiana, DX Central is a premier hub for the radio monitoring community, dedicated to advancing the hobby of DXing through live streams, online receivers, regular DX challenges and contests, educational content, and data-driven propagation analysis.

Media Contact: 

Loyd Van Horn | Founder, DX Central

Email:  inquiries@fmdxdata.com 

Web:  dxcentralonline.com 

Youtube:  youtube.com/@DXCentral 

Twitter/X:  twitter.com/DXCentral

Loyd Van Horn

W4LVH - Mandeville, LA

Member:  IRCA/NRC Courtesy Program Committee (CPC)

Founder: DX Central - Because we're all about radio

Web:  dxcentralonline.com

Twitter:  @DXCentral

YouTube:  youtube.com/c/DXCentral

Radio Broadcasting on the Pacific Islands of Tonga

 

Beautiful beaches of Tonga

Jeff: One of the island groups that still maintains broadcasts on medium wave that can be heard by DXers is the South Pacific island nation of Tonga.  Here’s Ray Robinson with the story of radio broadcasting in that country.

Ray: Thanks, Jeff.  The many scattered islands that make up the kingdom of Tonga in the South Pacific are grouped in a roughly north/south line over about 500 miles. The entire cluster of 171 islands lie northeast of New Zealand at the same latitude as the central coast of the state of Queensland in Australia.  These islands are mostly volcanic in nature, surrounded by a coral reef, and the total land area for the whole country is only about 290 square miles.

Only 45 of the Tongan islands are inhabited, and the current population is about 106,000, although more than double that number of Tongans live overseas, mainly in the USA, New Zealand and Australia.  70% of the resident population lives on the main island, Tongatapu.  The name Tonga, in many Polynesian dialects, literally means ‘southwards’, and it is thought that the archipelago became known by that name because it is the southernmost group of all the island groups in western Polynesia.

Historians state that the Polynesian peoples migrated from the Asian mainland some 4,000 years ago, and they scattered out over the many small islands in the Pacific.  It is generally considered that Tonga was settled by seafarers from Samoa around 1,000 BC.

Tonga was discovered by Europeans in 1616; the Dutch were first with several visits in the 1600’s, including by Abel Tasman in 1643.  Then came James Cook and the British Royal Navy in the 1770’s, and because he arrived at the time of a local feast to which he was invited, the name of the island group in English became the ‘Friendly Islands’ – a name which is still used to this day.  In 1797, Protestant missionaries from England settled in Tonga, and it was through them that the island chief was designated as a king, taking the throne name King George, as in England at that time.  The islands unified into a single country around 1845.

Tonga has maintained its sovereignty and remains the only Pacific nation never to have been annexed by a European power, and to have retained its monarchical government.  The Tongan monarchy follows an uninterrupted succession of hereditary rulers from one family.  Historically, these Friendly Islands entered a ‘Treaty of Friendship’ with the British government in 1900 for defence and foreign policy purposes, but without surrendering their sovereignty.  This ended in June 1970, whereupon they joined the British Commonwealth of Nations.

The first radio communication station in Tonga was established under the callsign VSB in the national capital, Nuku'alofa in 1921.  Other subsidiary communication stations were soon afterwards established on other islands, including Vava'u Island with the British callsign GON.

The first radio broadcasts from Tonga came from the American eclipse expedition on Tin Can Island in 1930, with the relay of news and commentaries back to the United States on shortwave via RCA Hawaii.

Another notable broadcast took place in May 1933 when Tonga produced a short segment that was transmitted on shortwave from station VSB and picked up by AWA near Sydney, Australia for inclusion in a very memorable program for that era, the "South Seas Broadcast."

On July 4, 1961, the Tonga Broadcasting Commission (TBC), solely owned by the government of Tonga, inaugurated the first regular radio broadcasting station in Tonga under the callsign ZCO with 10 kW on 1020 kHz.  This callsign was changed to A3Z exactly fourteen years later, and the medium wave channel was changed to 1017 kHz five years later again.  There were actually two 10 kW medium wave transmitters installed in the new radio station at Nuku'alofa, one as the active unit and the other for standby usage.

In the late 1980’s, TBC inaugurated a new shortwave service in Nuku'alofa in an endeavor to bring national radio coverage to all of the islands in the Tonga group.  The initial temporary shortwave unit was made locally and it was rated at just 200 watts.  A more substantial transmitter was installed shortly afterwards and it operated with 1 kW on the 60 metre band channel 5030 kHz, and an alternate channel of 6012 kHz SSB with carrier.  The antenna system was a horizontally polarized dipole beamed to the north.

However, the Tongan shortwave service was continually plagued with problems.  The transmitter was said to be faulty, and spare parts from the manufacturers in France took a long while to arrive.  A storm destroyed the antenna system in 1993, after which the United Nations UNESCO agency provided a new 1 kW transmitter and antenna system.  However, four years later again, Cyclone Hina caused further damage to the antenna systems and to the transmitter itself.

  

The shortwave broadcasts from Nuku'alofa were always a relay of the medium wave service, and the last known broadcasts on shortwave occurred in June 1997.  By this time, a new FM service was on the air, and FM relay stations were installed on the outlying islands.

In the late 1980’s, UCB, the United Christian Broadcasters in New Zealand, announced that they had received approval to install several radio stations in Tonga; on medium wave, FM and shortwave.  It was apparently their intent to operate a shortwave station that could be heard throughout the Pacific.  A lot of preliminary work was performed, and UCB did open a medium wave station with 5 kW on 738 kHz on Tongatapu.  Ultimately, though, they decided to concentrate on FM coverage only, with low power transmitters on several of the islands.

TBC Studios and Broadcast Tower, Nuku’alofa, Tonga

I said at the beginning that the Tongan islands are mostly volcanic in nature, and in January 2022, the Hunga volcano, 40 miles north of the main island of Tongatapu, erupted, causing a tsunami which inundated parts of the archipelago, including the capital Nuku?alofa.  Comparable to the size of the 1883 eruption of Krakatoa, the Hunga volcano produced an atmospheric explosion never before documented in the modern geophysical record.  The eruption affected the kingdom heavily, cutting off most communications and killing four people in Tonga.   It took around five weeks to repair a submarine fiber optic cable used for internet and telephone connectivity.

Electricity in Tonga is mostly generated by power stations fueled by imported diesel.  As a result of the current high energy prices caused by the conflict in Iran, they are now having to ration electricity through rotating power outages called load shedding, although this seems to be mainly during overnight hours.

Today, TBC operates two free-to-air TV channels (Television Tonga and Television Tonga 2), one AM commercial radio station (TBC Radio 1, also known as Radio Tonga), one FM commercial radio station (TBC Radio 2, also known as Kool 90FM), and a 24-hour Radio Australia relay station (FM103).  The funding of TBC relies mainly on profits from its TV & radio advertising sales.

The full formal ID of Radio Tonga is:  "THIS IS THE CALL OF THE FRIENDLY ISLANDS, RADIO TONGA 1 (A3Z), NUKU’ALOFA, TONGA."

 Here’s an audio clip of Radio Tonga a few weeks ago on Saturday March 21^st.  The languages used are both Tongan and English – listen out for ‘The Call of the Friendly Islands’.

 To hear the audio clip of  Radio Tonga 1, go to the audio link for April 26, 2026  at:  https://www.podomatic.com/podcasts/wavescan

The station has always been a good verifier with a distinctive QSL card, both under the old callsign ZCO, and under the current callsign A3Z.  Many of the QSL cards issued by the station carry unique postage stamps, such as one in the circular shape of a camera lens, and another in the shape of a banana.  So, if anyone manages to log this exotic MW DX catch on 1017 kHz, please let us know, and we’ll mention it here on Wavescan.

 Besides the TBC stations, there are also a half dozen or so privately owned 100 or 200 Watt FM stations, along with FM transmitters carrying China Radio International and the aforementioned Radio Australia.

 Back to you, Jeff.

(Ray Robinson)

Blog Logs - May 2026

 

                               Proving once again … that shortwave is not DEAD!

Welcome to the May 2026 issue of Blog Logs. Thank you for your emails, logging contributions and following my latest daily posts on X at Shortwave Central (Gayle Van Horn W4GVH@QSLRptMT).

Have you subscribed to the Shortwave Central YouTube channel? You will find a vast selection of videos and audio airchecks, and the Playlist is growing! Join your fellow radio enthusiasts at: https://www.youtube.com/c/ShortwaveCentral 

The Shortwave Central blog brings you the latest from the ever-changing realm of radio. Additional radio information is covered in my Bits & Bytes monthly column in The Spectrum Monitor e-zine at: https://www.thespectrummonitor.com/

Languages as indicated

// denotes station heard on a parallel frequency

*Sign-on Sign-Off*/ frequencies in kHz

Monitoring  January 1-27, 2026   

UTC, frequencies kHz 

Mediumwave

Argentina

840, Radio Salta, Salta. Spanish at 0053. Announcers with commentary and talk on items about tango music, friends, tourist items and advertisements for Salta. S-4 signal (Rudolf Grimm, Brazil).

1070, Radio Metropolitana, Mogi das Cruzes , São Paulo at 1631. Staton ID “Metropolitana” to comments on health to local time check (Grimm)

1220, Radio Eco Medios, Buenos Aires. Spanish programming at 0152 with romantic music with S-5 signal quality.(Grimm).

1230, Radio Dos, Rosario. Spanish text and talk from the announcer. Local ads and time checks to sports news from Rosario (Grimm).

Paraguay

920, Radio Nacional del Paraguay, Asunción. Spanish programming with a sequence of Paraguayan rhythm, accompanied by famous Paraguayan harps (Grimm).

970, Radio Universo, Asunción in Spanish. Sports news and mentions of Guarany, Olimpia, and Cerro Porte?o (Paraguayan soccer teams. S-6 signal quality (Grimm).

1080, Radio Minumental Chacoi. Spanish at 2346 with coverage of a soccer match. Local ads and sports talk for S-5 signal quality (Grimm).

United Kingdom

972, Sunrise Radio, 1957-1910. Bollywood music format, for a 24-hour schedule. ID at 1900 with singing jingles, promos, ‘Sunrise Radio”  into national news from Sky News-UK. (Van Horn, LA) YT video: https://youtu.be/cFAtprdztP4

Uruguay

1010, Radio Carve Deportina, Montevideo at 0120. Spanish sports news from Argentina and Uruguay. (Grimm).

1050, Radio Uruguay, Montevideo at 0131. Spanish speech from a public presentation. Music tunes, including classic - The Sound of Silence (Grimm)

1090, Radio Maria Uruguay, Montevideo. Spanish religious vocals with S-4 signal quality (Grimm)

Shortwave

Bolivia

3310, Radio Mosoj Chaski’, Cotapachi, 0002-0011 with Quechua comments during very weak signal. SINPO 15421 ((Manuel Méndez, Spain/BDXC/HCDX). Classic video from Oct 1, 2020 at: https://youtu.be/XmjTXz6OBdI

Brazil (Portuguese)

5039.4, Voz Missionaria, Camboriú, 0605-0627. Religious music and comments from the announcer (Méndez).

6150, Rádio Saturno, Belo Horizonte 0556-0621. Brazilian music tunes to clear station ID and comments. SINPO 15422. (Méndez) 

6180, Rádio Nacional da Amazônia, Brasília 0742-0753. Brazilian music to station comments. Signal fade out // 11780. SINPO 15421 (Méndez).

6200, Rádio Ancora 0601-0633. Brazilian music to station info and station ID. SINPO 15422 (Méndez).

15189.8 Rádio Inconfidência, Belo Horizonte, 1942-2011. Brazilian music, program comments “Delinio e Cía to ID “Inconfidencia.” Station located, given program name and local time check. SINPO  25433 (Méndez).

Clandestine

5920, NKHB 1727-1735. Transmitter on at 1727 to interval signal at 1828. “NKHB” identification, following by contact info and repeat of ID into Korean religious readings (Van Horn, LA) YouTube video: https://youtu.be/RRcLxE0QwK8

6110, Radio Zamaneh via Bulgaria relay 2017-2030. Tune in to African vocals to low-level audio talking about Tehran. Additional music and station ID’s. (Van Horn, LA) YT video: https://youtu.be/eBMdZPRk39w

11640, Radio Dabanga via Talata-Volonondry, Madagascar relay at 0445. Sudanese Arabic programming with fair signal quality. Announcer’s text and African music (Pearson).

15215, Radio Zaman Bidari 1828-1835 via France relay. Farsi broadcast with opening ID, frequency, and website info into the national anthem. Lady announcer’s programming to Iran. (Van Horn, LA) YT video https://youtu.be/LMSf46whIQU

China

4905, Xijang Tibet – PBS RTV, Lhasa Chengguan 1738-1804.* Tibetan comments and local music // 4920 and 7385 kHz. SINPO 15422 (Méndez).

Colombia

6010, Alcaravan Radio via Puerto Lleras 0400-0515. Spanish religious text and vocal hymns (Rod Pearson, FL)

Netherlands

6129.98  Radio Europe, Alphen a/d Rijn, in English/Dutch, 04.19.2026, 0107-0130.  With techno music to the station ID and a brief announcement. Music program of disco pop, rock, and electro house. Additional ID and similar programming. (Gio Serra, Italy/NASWA) 

North Korea

9875, Voice of Korea/KCBS Kujang. Korean program at 2029 to 2036. Programming targeted to the Middle East. Additional monitoring on 11910 to Africa 1942-1950 (Grimm).

Palau

9965, T8WH/Hope Radio Five at 0800. Religious text and choral hymns for fair signal quality (Pearson).

Peru

4775, Radio Tarma 0002-0013. Spanish programming about charismatic healers. Local ad and time check (Mendez).

Philippines

9400, FEBC-Radio Liangyou 1, Iba 1145-1150. Mandarin service with FEBC info and promotions. Religious scripture format. (Frank Hilton, SC).

South Korea

15575, KBS World Radio, Kimjae. English programming with news on North Korean threats. Signal poor-to fair. (Pearson).

Spain

17715, Radio Exterior de España, Noblejas 1841-1857. Spanish programming to South America, including interviews about various foreign policy matters. Additional world news into the program 24 Hours.Good reception – SINPO 45544 (José Ronaldo Xavier, Spain/HCDX).

United Kingdom

classic QSL

15265,  KBS World Radio relay via Woofferton. Russian programming at 1831, with K-Pop tunes and an announcer’s talk. Fair to poor signal quality. (Tony Pavick, BC, Canada) 

United States

11860, Radio Martí, 1610-1620. Spanish national news on the U.S. and Cuba. Noted on 11930 with station IDs, info, frequencies, and “Radio Marti” ID (Hilton) 

17790, Radio Africa/Pan American Broadcasting via WRMI Okeechobee. English to Latin America at 1809-1817. Announcer’s talk and ID (Grimm).

15150, WMLK Bethel, PA 1632-1645. Classic religious teachings from Elder Jacob O’Meyer. SIO 433 (Hilton)

Uzbekistan

6035, BBC World Service via Tashkent relay in English to South Asia at 0004-0009. Tashkent relay for Radio For Peace International on 15640, to Iran at 0515-0535. Commentary and station ID, to signal cut at 0530 (Grimm).

Vanuatu

7260, Radio Vanuatu, Port Vila 0634-0655. Local songs and program comments. Very weak signal as SINPO 15411. Noted on 9660 at 0510-0558.” English promos and island music to Bislama announcements. SINPO 15422 (Méndez).Classic video from Nov. 19, 2025 

https://youtu.be/kP_0d3UgKSk

Vatican State

9705. Vatican Radio via Santa Maria di Galeria, 1935-1946. French service for The Way of the Cross. SINPO 35444. Additional Vatican Radio tuning from the same location as: 11870, 1926-1948 in English; 15565, 1928-1942 in Portuguese (Méndez).

9710, Radio Vaticana, 0500 in Russian to interval signal and 0500 ID, followed by announcer’s text. (Pavick) 

New edition of International Radio Report available

 

Hans Knot writes:

It’s now well into spring, the garden is ready for summer, so I suddenly found myself with time to put 

together a new International Radio Report. 

The second edition for 2026 of this report, which has now been running for 25 years, features a host of fascinating historical topics with contributions from Robbie Owen, Don Stevens, Andy Cadier, Look Boden, John Hogg and Dennis King, amongst others. I also delve into the notes I made in 1973 and 1974 regarding Radio Atlantis. The report can be downloaded via the following link, and I hope you enjoy reading it.

https://offshoreradio.info/wp-content/uploads/2026/04/hans-knot-int-radio-report-2026-02.pdf

VOA Greenville Transmitting Facility 1967

 

Thanks to Mike Barraclough of BDXC for posting the following

Page 1 

 

At the center of the VOA’s Greenville 4,800,000 watt broadcast¬ ing complex is “Site C,” the receiving station whose courtyard is seen above. Incoming programs from Washington, D.C., pass through the Site C control console to transmitting Sites A and B. Incoming overseas teletype and voice feeds are sent to Washington.

Remotely operated rf switchgear, one of two identical units, channels nearly 3 megawatts of power to an antenna field which covers two miles and more in length ... and contains huge curtain antennas rising nearly 300 feet, and rhombics over a quarter of a mile long. Both rhombics and curtains, used interchangeably, are beamed at such distant cities as: Moscow, Prague, Cairo, Lagos, Rio de Janeiro, Santiago and Tegucigalpa.

 

https://www.worldradiohistory.com/Archive-Modern-Era-Miscellaneous/VOA-Greenville-1967.pdf

 

Weekly Propagation Forecast Bulletins

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Apr 27 0538 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 20 - 26 April 2026

Solar activity ranged from low to high levels. The strongest events of the period were an X2.4 flare (R3-Strong) at 24/0107 UTC and an X2.5/2B (R3) at 24/0813 UTC from Region 4419 (N14, L=314,

class/area=Eki/360 on 17 Apr). The X2.4 flare had an associated Tenflare and CME signature. Modeling of the CME indicated possible influence from the far periphery of the event on 26 Apr. The X2.5

flare had an associated Type II (est 1,293 km/s), Type IV, and Tenflare (570sfu) as well as a CME signature in coronagraph imagery. Modeling of this event suggested the primary bulk of the plasma was

not on the Sun-Earth line. 

Other major X-ray events included an M6.4/1F (R2-Moderate) at 24/1815 UTC from Region 4419. The resulting CME was off the Sun-Earth line. An M6.0 (R2) flare 26/2257 UTC from Region 4420

(N16, L=225, class/area=Fki/400 on 25 Apr). As associated Type II (est 834 km/s) was reported with this event as well as a 30,000sfu burst on 245MHz. No CME signature was identified in subsequent

coronagraph imagery. 

13 other M-class (R1-Minor) events were observed over the past week with many producing radio and CME signatures. However, those events that were associated with CMEs did not contain an Earth-directed component. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit reached high levels on 20-24 Apr and remained at normal background to moderate levels for the remainder of the report reporting period. 

Geomagnetic field activity reached G1 (Minor) storm levels on 20-21Apr due to the influence of a negative polarity CH HSS. Solar wind speeds peaked around 550 km/s and total magnetic field strength

increased to a brief peak of 10 nT on 20 Apr. The Bz component reached as far south as -8 nT during the HSS. Quiet to unsettled conditions were observed over 22-25 Apr. A negative polarity coronal

hole, with possible weak embedded influence from a CME that left the Sun on 24 Apr, caused isolated active levels on 26 Apr. Solar wind speeds remained below 500 km/s with this coronal hole. 

Forecast of Solar and Geomagnetic Activity 27 April - 23 May 2026

Solar activity is expected to reach moderate levels (R1-R2/Minor-Moderate), with a slight chance for high (R3/Strong), from 27 Apr - 04 May due to the flare potential from multiple active regions on the solar disk. The remainder of the outlook period is likely to be at low levels, with a slight chance for M-class (R1-R2). 

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 12 Apr, 29 Apr - 05 May, 08-14 May, and 17-21 May due to the anticipated influence from multiple, recurrent, CH HSS. The remainder of the outlook period is likely to be at normal to moderate levels. 

Geomagnetic field activity is expected to reach G1 (Minor) geomagnetic storm levels on 07 May and 15-16 May. Active conditions are likely on 27 Apr, 30 Apr, 08 May, 17-18 May, and 23 May.

Unsettled conditions are likely on 29 Apr, 01 May, 03-04 May, 09 May, and 21-22 May. All enhancements in geomagnetic activity are due to the anticipated influence of multiple, recurrent, CH HSSs. The remainder of the outlook period is expected to be at mostly quiet. 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Apr 27 0538 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-04-27

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Apr 27     155          12          4

2026 Apr 28     150           7          2

2026 Apr 29     150          10          3

2026 Apr 30     152          14          4

2026 May 01     152           8          3

2026 May 02     148           5          2

2026 May 03     142           8          3

2026 May 04     140           8          3

2026 May 05     140           5          2

2026 May 06     135           5          2

2026 May 07     135          20          5

2026 May 08     135          15          4

2026 May 09     120           8          3

2026 May 10     110           5          2

2026 May 11     115           5          2

2026 May 12     115           5          2

2026 May 13     120           5          2

2026 May 14     120           5          2

2026 May 15     118          25          5

2026 May 16     130          20          5

2026 May 17     135          20          4

2026 May 18     135          15          4

2026 May 19     135           5          2

2026 May 20     140           5          2

2026 May 21     140           8          3

2026 May 22     145          10          3

2026 May 23     145          12          4

(NOAA)

U.K. Propagation Update

 

RSGB

RadCom Assistant Editor | April 24, 2026

Compiled by G0KYA, G3YLA and G4BAO on 23 April, 2026

Last week’s HF propagation was dominated by the effects of a high-speed stream from a large coronal hole on the Sun.

This pushed the Kp index up to 4 and 5 at times with the result that maximum usable frequencies, or MUFs, were lowered. The ionosphere struggled and often the MUF over a 3,000km path was below 21MHz.

Yes, there were some openings up to 10m but they were generally weak. Checks showed that paths opened up to Brazil, Kenya and Chile on the 10m band using FT8, but the signals were well down in the noise and barely workable.

Get used to this as it could be the norm for the next few years!

Meanwhile, the solar flux index increased to 116 by Thursday, 16 April, no doubt aided by active sunspot group 4420.

Next week, NOAA forecasts that the solar flux index could rise to 125. It also predicts that the Kp index may remain low due to a lack of coronal hole activity. Fingers crossed that we don’t have any coronal mass ejections over the next week.

If this pans out as predicted, we could have some decent HF conditions over the next seven days. Yes, the MUFs may be lower, but 14, 18 and perhaps 21MHz could be usable, with very occasional openings on 24 and 28MHz.

DX to be worked this week includes TX9W from the Marquesas Islands; VP9KF in Bermuda; 7P8WR from Lesotho; C5B, C5C and C5D in The Gambia; D60DX in Comoros; and JD1BMH operating from Ogasawara.

VHF and up propagation news:

Compiled by G3YLA and G4BAO

The strong region of high pressure will remain with us for the next two weeks. So tropo should be considered a first-choice mode for a while.

The main criteria for the quality of any resulting tropo is moisture. This is because moisture is a component in the calculation of the refractive index of the air.

High pressure usually produces dry air above any temperature inversion but we may not always get the moisture below the inversion.

The end of last week was good with reports of beacons in Norway and Sweden into JO02 on 1.3GHz because of moisture present below the inversion.

However, if the dry easterly wind returns, it may not go so well.

Meteor scatter should continue to be uplifted by the declining Lyrids meteor stream, which peaked last week, and rain scatter is off the menu since the charts are dominated by high-pressure systems.

Aurora is showing as occasional weak alerts, but apart from the odd fluttery signals on the LF bands, nothing too interesting at the moment.

As usual, watch for the Kp index going up to 5.

Keeping the best until last, we are approaching the period when Sporadic-E usually becomes a mode of interest.

Work is well underway on a rewrite of the Propquest website, which should be ready soon. This will be the go-to place for the daily updates during the 2026 Sporadic-E season.

EME now, and the Moon is moving into a lower noise position. Declination is high but falling and path losses will increase as we move away from the Moon’s perigee, its closest point to Earth, which occurred on Friday, 17 April.

Apogee, the Moon’s furthest point from Earth and the point of highest path losses, occurs on Sunday, 17 May.

https://rsgb.org/main/blog/news/gb2rs/propagation-news/2026/04/24/propagation-news-26-april-2026/

(Mike Terry/BDXC)

Throwback Thursday - The Lonely Voice from Down Under!

This week's edition originally aired on March 5, 2000

Girls' High School, Sydney, Australia

The Lonely Voice from Down Under!

What happened to the original radio base that carried the shortwave programming from Radio Australia?

In the western suburbs of Sydney, there is a Girls' High School standing on a spacious and attractive property. Nearly 100 years ago, this location was in an isolated area, some 20 miles distant from old and faraway Sydneytown. Ask the students who are attending the high school today: "Do you know the important history of this property?" At a guess we would probably say no, most of them do not know the interesting background associated with this property. This school property was at one time the site for one of the world's largest radio stations.

It was here in Pennant Hills that the newly-formed federal government purchased the 40-acre property quite early in the last century for the purpose of establishing a large wireless station. Electrical engineers came out from Germany to install the newly developed Telefunken wireless apparatus, and finally, on August 19, 1912, wireless station POS was inaugurated. The original transmitter was a 25 kw spark unit and the antenna was an omnidirectional vertical radiator; in other words, just simply a tall steel mast.

Station POS was intended to become the key station in a nationwide network of wireless stations for the purpose of intercommunication throughout the Commonwealth of Australia and its territories. The callsign POS stood for "Post Office Sydney," and the counterpart near Perth in Western Australia, some 3,000 miles distant, was POP. However, the callsigns were soon changed to conform to the new international regulations, and POS and POP became VIS and VIP, as they are to this day.

A large number of radio transmitters were installed over the years at this Pennant Hills location, many for communication traffic and some for radio broadcasting. During the year 1927, a new building was erected on the Pennant Hills property, specifically to house a new 20 kw shortwave transmitter. This unit made its inaugural broadcast under the now nostalgic callsign VK2ME on October 27, 1927, with its famous first "Empire Broadcast."

Soon afterwards, two more shortwave transmitters were installed at Pennant Hills, and these were in use as VLK and VLM for international communication and as VK2ME for program broadcasting.

When the climactic events of 1939 finally broke out into open warfare, the Australian government hastily organised an international shortwave service under the designation "Australia Calling." At Pennant Hills, the two transmitters on the air previously as VK2ME and VLK-VLM became VLQ and VLQ2, and they went on the air with the inaugural broadcast of "Australia Calling" on December 20, 1939 with programming from the studios of the ABC in Sydney.

This shortwave station, "the lonely voice from down under," was on the air for six years as the main facility for Radio Australia. However, when the new shortwave station at Shepparton in Victoria was commissioned in 1944, the usage of Pennant Hills was terminated. The AWA radio station at Pennant Hills then reverted back to full time usage as a communication facility, though occasionally the 10 kw transmitter VLN was on the air with Radio Australia programming beamed across the Pacific.

The Pennant Hills radio station was finally and forever closed on October 31, 1955 when all services were transferred to a newly constructed facility located at another Sydney suburb, Doonside. The property was sold, and upon it was built the Carlingford High School.

The only reminders left in the radio world of this once powerful voice from down under are references in old radio magazines and QSL cards in old collections. The AWR historic collection in Indianapolis contains two original QSL cards from the old VK2ME, both in color, with a laughing Kookaburra superimposed on an outline map of Australia. One card is dated 1932 and the other 1937.

(Wavescan 271/3/5/2000)

(photo/FB-Old sydney Album)

Radio Comes to Australia

 Special thank you to the Wavescan staff for sharing this week's edition of nostalgic radio in Australia

Jeff: In the early 2000’s, our editor-in-chief, Dr. Adrian Peterson, wrote a series of articles under the strapline ‘Reminiscing with a Radio’, about his recollections of early radio listening in Australia.  Just over 20 years ago in March 2006, one of these articles was titled ‘Australia Gets Radio.’  Here’s Ray Robinson in Los Angeles with that story.

Ray: Thanks, Jeff.  Adrian’s own personal memories of radio broadcasting in his hometown of Adelaide immediately after the end of World War II in 1945 prompted him to write about events 27 years earlier, immediately after the end of World War I.  He wrote:

The war was over, troops were returning home, families were reuniting, difficult restrictions were progressively lifted, and technological development for peaceful purposes was resumed.  This was the scene in Australia, and in many other countries also, at the beginning of the era when wireless became radio.

During the war, the annual Royal Perth Show, always held in the autumn, was temporarily discontinued, “for the duration”.  This popular event was reintroduced just before the end of the war and it attracted huge crowds of eager spectators.  On the occasion of this first (almost) post-war show, wireless experimenter Wally Coxon staged a public demonstration of radio broadcasting with a transmitter in one pavilion and a receiver in another.  The year was 1918, and this was the first public demonstration of radio broadcasting in Australia.

In the Eastern States, the first experimental radio broadcasting transmitter was constructed just four months after the first direct wireless communication from England to Australia.  The enterprising Ernest Fisk was the Managing Director of AWA, and Fisk invited William Bostock, a decorated war veteran who had recently returned to “civvy street”, to head up the project.  Work began to build a radio transmitter in early 1919, using the newly available Marconi “Q” valve imported from England.  Bench tests were made from this new transmitter during the month of March, and then it was ready for wider experimentation.

One of the main uses of wireless transmissions had been for ship-to-shore communications, and so it was decided to install the new radio transmitter on a ship.  There was a fourteen-year-old single-stack interstate passenger/cargo vessel plying the Australian coastline at that time called the “Riverina”, owned by Huddart Parker of Melbourne.

Arrangements were made for the “Riverina” to carry the new little “Q” transmitter during its regularly scheduled voyages for a three-week series of seaborne test transmissions.  These test broadcasts took place during the month of April, 1919.  The output power was around 10 watts, and the operating frequencies were in what are now designated as the longwave and medium wave bands.  These experimental broadcasts were successful, although of course, there were very few receivers capable of tuning in to the informal programming.

 At the same time, there was another single-stack steamer plying the Australian coastline – the fifteen-year-old “Bombala” owned by Howard Smith, also of Melbourne.  A second series of test transmissions using the same “Q” transmitter was carried out in July of 1919.  Clear signals were heard over the salt water pathway at a remarkable distance, even as far away as Gabo Island, more than 300 miles south of Sydney.

Having proven the concept, the next event needed was a genuine public demonstration, and that was soon in the making.  Ernest Fisk announced that he would address the Royal Society of New South Wales on Wednesday evening August 13 (1919) and that he would present a live radio program as a practical demonstration of the new radio medium.  This event, as a historic first in Australia, was staged in the Royal Society’s Hall at 7 Elizabeth Street in Sydney.  A series of some twenty locally-constructed loud speakers with tin horns were all connected to the same receiver and strung from the ceiling.  The “Q” transmitter was installed at AWA Wireless House (at 97 Clarence Street in those days) and the sixty foot long “T” type antenna was strung on the roof of the same building.  The programming for this first auspicious occasion consisted entirely of gramophone recordings played into a carbon microphone.  At the appropriate timing during the Fisk speech, the National Anthem came through suddenly and dramatically; a clear demonstration that radio without wires was indeed a reality.  The transmitted signal had traveled in the heart of old Sydneytown from one main street to another covering a distance of about half a mile.

Meanwhile, down in Melbourne, AWA was planning another series of dramatic radio events.  It should be remembered at this era, that Sydney was the larger city, but Melbourne was assuming political importance as the de facto capital of Australia due to the fact that the Federal Parliament was headquartered in this city.  (The Australian Capital Territory, ACT, and the city of Canberra had not yet been surveyed.)  Two Marconi speech transmitters were imported from England and one was installed in the Brighton home of the local AWA manager, Lionel Hooke, with a simple antenna in the family garden.  This unit came on air with a special broadcast to the Federal Parliament which was meeting in Queen’s Hall, Melbourne.  The date was Wednesday October 13, 1920; the receiving aerial was installed on the roof of Parliament House; and the loud speakers were the ones with tin horns from Sydney.

AWA conducted many promotional test broadcasts in the Melbourne area during this period.  The 500 watt transmitter was transferred from Hooke’s residence to another suburban residence, that of engineer Sydney Newman in Canterbury.  At this location, the familiar callsign 3ME was introduced.  In fact, AWA in Melbourne registered a series of callsigns ranging from 3MA – 3ME.  Station 3ME was installed at the permanent fixed location of Canterbury, but the others were apparently used at various temporary locations for demonstration test broadcasts using another 500 watt Marconi transmitter.  These two transmitters, twins from Chelmsford in England, were rated at less than one “horsepower”!

At this stage, the AWA callsigns in Melbourne became quite prominent, in fact more prominent than the similar series in Sydney, 2MA – 2ME.  In particular, the Melbourne callsign 3ME was soon afterwards transferred to Braybrook where it identified a shortwave transmitter co-sited with 3LO.  It was not until AWA began a series of international shortwave broadcasts from Pennant Hills near Sydney that the 2ME callsign became better known than the southern sister 3ME.

Throughout the five-year period from early 1919 to late 1923, the number of radio broadcast programs, and the number of radio broadcasting stations, all experimental and mostly amateur, began to proliferate, mainly in Sydney & Melbourne, though also in other cities as well.  In Sydney there were 2CM & 2MB; in Melbourne 3ME & 3DP; in Brisbane 4CM & 4CH; in Adelaide 5AH & 5BN; and in Perth 6AG; plus a host of others that came and went as well.  In fact, there were so many amateur broadcasters on the air in Sydney for example that the newly-launched “Wireless Weekly” established an evening rota for all amateur broadcasting stations in an effort to reduce interference.

As a result of all of this amateur broadcasting activity, it became evident that Australia needed a regular licensed broadcasting system.  In 1923, two organizations in Sydney applied for broadcast licenses, and construction work on both was carried out simultaneously.  The first on the air was 2SB, followed soon afterwards by 2FC.  Test broadcasts for 2SB began on October 19, 1923 with the use of another hurriedly constructed 10-watt transmitter.  This unit was installed in the Smith’s Weekly building in Phillip Street and the amateur callsign, 2HP, was transferred from William MacLardy’s suburban location to the new facility in the city.

This new radio broadcasting station was officially opened on November 23, 1923, with a new 500 watt transmitter operating at lower power under its official callsign, 2SB.  This call was changed early in 1924 to the more familiar 2BL.  Similar officially licensed radio broadcasting stations were soon afterwards inaugurated in each of the other state capitals throughout Australia.

Back to you, Jeff.

Update on the future of Radio Seagull

 

Radio Seagull on Facebook

By Martin Wallis

14 April 2026

An article from our regional radio and TV station ‘Omrop Fryslan’ in the Frisian language:

It was such a great plan: the red lightship Jenni Baynton from Harlingen would go out to sea again, to make radio broadcasts from behind anchor. So the foundation behind the ship wanted to raise money for the maintenance, which is much needed. But it won’t continue. The diesel is too expensive.

The Jenni Baynton is the last ship that still broadcasts radio. It has a similar history to that of Radio Veronica. It started as a sailing lighthouse in 1949. After that, it was also a disco when it was located in Rotterdam.

In 2005, the Friends of the Lightship Foundation bought it, and the volunteers turned it into a functional ship again. Between 2005 and 2015, for example, Radio Waddenzee could be heard from the ship. The

ship would anchor in the Wadden Sea for five weeks. Not only to make radio, but also for other cultural events. And although the ship’s engines do not use much diesel when it is at anchor, electricity is needed. This is also generated on the old ship with diesel.

According to the board of the Friends of the Lightship foundation, the price of diesel has recently become so high that the cost of electricity on board can rise to 300 euros per day. Then the whole action would no longer generate any money, but money would have to be added.

The money would be used for a shipyard overhaul. The last shipyard overhaul the ship received was in 2009. The Friends of the Lightship Foundation, therefore, wants to make the ship look good again. Volunteers usually maintain the ship, but for a major overhaul, it has to go to a shipyard and the costs to do so are high.

 From June 1 to July 7, the ship will not be anchored at sea, but with its ropes on the shore in Harlingen. This also has an advantage, says the board: it will now be much easier for visitors to get on board.

It is possible that the ropes will still be loose for a while with the Tall Ships Races. These will be in Harlingen from July 3 to 6. The board is now investigating whether this is possible. “That beautiful red

Lightship as a gatekeeper at the entrance to the harbor to welcome the sailing ships does have some extras”, says the board.

Mike Terry to nordx iog (2026-04-15)

(Ydun's MW & LW Info)

Weekly Propagation Forecast Bulletins

 Product: Weekly Highlights and Forecasts

:Issued: 2026 Apr 20 0331 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web contact https://www.swpc.noaa.gov/content/subscription-services

#

#                Weekly Highlights and Forecasts

#

Highlights of Solar and Geomagnetic Activity 13 - 19 April 2026

Solar activity was at very low to low levels during the period. Very low levels occurred on 14, 15 and 19 Apr, while low levels were observed on 13, 16, 17, and 18 April. 

Region 4419 (N14, L=314, class/area=Eki/360 on 17 Apr) was the most active region of the period, responsible for 5 out of the 7 C-class flares observed during the week, including the largest one: a C4.1/Sf at 17/0442 UTC. The remaining 2 C-class flares of the period were: a C1.1/Sf at 13/1137 UTC from Region 4414 (N15, L=026, class/area=Dro/030 on 08 Apr) and a C1.6 at 18/0704 UTC from Region 4416 (N19, L=047, class/area=Dai/140 on 12 Apr). Coronal activity was observed during the week with some filament eruptions and few CMEs without Earth-directed components. 

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at high levels on 13-17 Apr, followed by a day at moderate levels on 18 Apr and returning to high levels on 19 Apr, with a maximum flux of 3,250 pfu observed at 15/1800 UTC. 

Geomagnetic field activity was quiet to Moderate storm levels during the period. From 13 to 17 Apr, the geomagnetic activity remained at quiet levels. On 18 Apr, the arrival of a negative polarity CH HSS influence disturbed the Geospace, elevating the activity from unsettled to Moderate storm levels. On 19 Apr, Moderate storm levels were observed during an isolated synoptic period (0600-0900 UTC) and the geomagnetic activity returned to quiet level by the end of the day as the CH HSS effects waned. 

Forecast of Solar and Geomagnetic Activity 20 April - 16 May 2026

Solar activity is expected to be at low levels, with a varying chance for M-class (R1-R2/Minor-Moderate) flares and a slight chance for X-class (R3/Strong or greater) flares through 16 May. 

No proton events are expected at geosynchronous orbit, barring any significant, non-recurrent solar activity. 

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on 20-22 Apr, 27-28 Apr, 30 Apr-05 May, and 08-14 May. Normal to moderate electron flux levels are expected on 23-26 Apr, 29 Apr, 06-07 May, and 15-16 May. 

Geomagnetic field activity is expected to remain at quiet to active levels during most of the outlook period, with the exception of 5 days when G1 (Minor) storm levels are anticipated due to the recurrent influence of CH HSS: 29-30 Apr (-CH HSS), 07 May (+CH HSS) and 15-16 May (-CH HSS). 

Product: 27-day Space Weather Outlook Table 27DO.txt

:Issued: 2026 Apr 20 0331 UTC

# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center

# Product description and SWPC web https://www.swpc.noaa.gov/content/subscription-services

#

#      27-day Space Weather Outlook Table

#                Issued 2026-04-20

#

#   UTC      Radio Flux   Planetary   Largest

#  Date       10.7 cm      A Index    Kp Index

2026 Apr 20     105          18          4

2026 Apr 21     110          15          4

2026 Apr 22     120           8          3

2026 Apr 23     125           5          2

2026 Apr 24     120           8          3

2026 Apr 25     115           8          3

2026 Apr 26     120           5          2

2026 Apr 27     125           5          2

2026 Apr 28     125           5          2

2026 Apr 29     125          20          5

2026 Apr 30     125          18          5

2026 May 01     125          12          4

2026 May 02     125          10          4

2026 May 03     115           8          3

2026 May 04     108           8          3

2026 May 05     105           5          2

2026 May 06     100           5          2

2026 May 07      95          20          5

2026 May 08      90          15          4

2026 May 09      90           8          3

2026 May 10      95           5          2

2026 May 11     100           5          2

2026 May 12     105           5          2

2026 May 13     110           5          2

2026 May 14     110           5          2

2026 May 15     105          25          5

2026 May 16     105          20          5

(NOAA)