A quick look at the 11-metre broadcast band - Spring 2024

The highest HF band used for broadcasting is the 11-metre band which runs from 25.6 MHz to 26.1 MHz. It's an unusual band and many of the smaller receivers don't even go that high in frequency. Even in the golden days of short-wave broadcasting, very few stations used it.

As we're near the peak of the sunspot cycle, I went looking to see what exactly is on the band and who is using it.

As far as I know, there are three transmitters using the band and these are shown above.

This is the schedule for January to March 2024....

Frequency (kHz) - Station - Times in UTC - Transmitter

25800 kHz - World Music Radio - 24-hours - Denmark - 0.060 kilowatts

25900 kHz - BBC World Service (French) - 12:00 to 12:30 - Madagascar - 250 kilowatts

25900 kHz - BBC World Service (English) - 16:00 to 18:00 - England - 125 kilowatts

Report & information...

1) World Music Radio transmits from Aarhus in Denmark with just 60-watts on 25.8 MHz. In terms of broadcasting on AM, this would be considered very low power.

The antenna is likely to be very modest but it does seem to be on top of a very high tower as shown above.

Back in the summer of 2021, I had a post on the blog about how I had heard it via Sporadic-E propagation. I tried listening for it today at around midday on the 11th of January 2024 and I could make out a weak carrier on CW. 

It was way too weak to resolve on AM today but it's highly likely that it was the World Music Radio transmitter I was receiving. I did notice the carrier was inclined to drift a bit (~5-10 Hz) but that doesn't make any difference for an AM signal.

2) The BBC World Service transmits to Africa in French on 25.9 MHz from a 250-kilowatt transmitter at Talata-volonondry on the island of Madagascar. Considering the transmission only lasted 30 minutes, I presume this is a commercial site where broadcasters rent time on it.

The signal was S9 when I listened to it and I think anyone in Europe should hear it as it's a north-south path.

3) The final transmitter was the BBC World Service in English which broadcasts to Central and West Africa on 25.9 MHz. The 125-kilowatt transmitter is located in Woofferton in the east of England and this transmission lasted two hours.

This transmitter is 390 kms from my location on the south coast of Ireland so I am well inside what is considered to be the F2-layer skip zone. Just after 16:00 UTC, the signal was about S4 on CW. On AM, I knew someone was speaking English but it was very difficult to hear.

Propagation Modes???... The signal from Madagascar is easy enough, it's multi-hop F2 with possibly some TEP in there as well.

As for the 60-watt signal from Denmark? At 1300kms, it was probably a bit too close for F2 layer. Maybe F2 layer backscatter or ionoscatter?

For the signal from England, it was stronger at 16:00 as compared to 18:00 UTC so it wasn't ground wave or some sort of tropo. The ionosphere was certainly involved. Again, either F2-layer backscatter or forward ionoscatter.

In conclusion... It was interesting to see some activity on the 11-metre broadcast band. I suspect though it may be on borrowed time. Two broadcasters seem to be using it for the peak of this sunspot cycle but will anyone be using it at the peak of the next one in eleven years time?

Ongoing DRM tests at 86.5 MHz in Copenhagen - 2022

I came across an interesting news report recently about an Digital Radio Mondiale (DRM) test that is currently taking place on 86.5 MHz in Copenhagen, the capital of Denmark.

While several countries have DAB systems up and running, some are carrying out test in or around Band 2 (88-108 MHz) and seeing if digital DRM signals could co-exist with analogue FM signals.

The DRM test in Copenhagen started on the 13th of October 2021 and runs until the 1st of August 2022. There is an option of extending this to the 30th of August 2023.

This is a collaborative project organised by Open Channel, an independent Danish network operator in Copenhagen, with Canadian Nautel (transmitter), German RFmondial (DRM modulator & measuring instruments) & Fraunhofer IIS (Content server) and Swedish Progira (network planning).

The project is supported by Gospell, NXP, partners in Denmark and other non-DRM Consortium members like Bauer Media (supplying content) and Kathrein (antenna).

The frequency allocated is 86.5 MHz and with a bandwidth of 200 kHz, which makes room for two DRM signals. Each DRM signal has a capacity of 186.4 kbps (16QAM, CR 5/8) and accommodates three audio channels and multimedia services, so for the 200 kHz a total of six digital radio stations can thus be broadcast. Further down the line there are ambitions to involve the Öresund region (commonly known in English as the Sound, a strait which forms the Danish–Swedish border) and possibly collaborate with another FM station on the Swedish side.

The height of the antenna is 88m and the terrain elevation is 8m (more details below). In phase 1, Open Channel will test single DRM channel with 120 Watt ERP. The coverage probability for mobile reception in Greater Copenhagen is illustrated in the picture below...

The trial on the 86.5 MHz frequency has also been approved by the Swedish Post and Telecom Agency. The fact that the experiment is done a bit below the regular FM band (band II 87.5-108 MHz) is due to the fact that there is no space in this dense region. The new receivers for FM/DRM can handle 64-108 MHz.

“We are working on expanding the FM band in Denmark from 85 – 87.5 MHz, so that the Danish FM band goes from 85 to 108 MHz and thereby create more space to introduce digital radio on the FM band”... says Kenneth Wenzel, project manager and director of Open Channel.

“This DRM field trial offers a unique opportunity to showcase the versatility of DRM-FM by packing two DRM signals within a single FM channel allocation demonstrating optimal spectral efficiency for DRM using a Nautel VS transmitter.”... says Philipp Schmid, CTO at Nautel.

Source... https://www.drm.org/drm-for-fm-in-the-heart-of-europe/

"Energy Island" to become a new IOTA for Denmark???

 

I was reading an interesting news article today about a new project to build a giant island off the coast of Denmark in the North Sea. It will serve as a hub for 200 giant offshore wind turbines.

The world's first energy island will be as big as 120,000sq m but there are hopes to make it as large as 460,000sq m. It is the biggest construction project in Danish history, costing an estimated 210bn kroner (£24bn; €28bn: $34bn).

IOTA... Located some 80kms or so off the Danish coast, I couldn't help thinking if it would qualify as a new IOTA reference?

The IOTA (Islands On the Air) awards programme is very popular with radio amateurs and is probably  second only to the DXCC programme in terms of popularity. I'm sure a new Danish IOTA reference would generate some interest.

Would it count though? From what I understand, it must be a certain distance offshore and 80 kms should certainly qualify. However, I think it must also be 1km in length. If it expands to its full size then it might.

Does a new large artificial island qualify as a new IOTA reference?

Update: It would seem that it won't count as a new IOTA as qualifying islands can't be man made.

VHF...  Whatever about IOTA, the new 'Energy Island' would be located out in a very wet locator square... either JO35 or JO36 and it would certainly count.

Considering how close it would be to Germany, the Netherlands and the UK, it would probably be very popular on all the VHF bands.

Noise?... While it's interesting to hear about new islands popping up out of the North Sea, it would hardly be a RF quite location with all of those inverters. Would radio communications be even possible on the HF bands? Would it even be allowed?

Update on the 40 MHz OZ7IGY beacon in Denmark - Jan 2021

Thanks to Ivan OZ7IS for the following update on the Danish OZ7IGY beacon on 40 MHz (8m).

Since the start back in 2007 the OZ7IGY 40 MHz beacon has been running on yearly experimental licenses based on reasoned applications. It has been increasingly difficult to come up with new good reasons every year. As a result it was off air in-between licenses. 

The last five months of 2020 it was off-air! As all 12 OZ7IGY beacons together represent an operating cost of approx. 2500 € every year the 40 MHz beacon was occasionally switched off for economic reasons. After all OZ7IGY beacons switched to the “Next Generation” platform a new problem arose: The 40 MHz beacon interfered with the microwave beacons and was therefore switched off for several periods. 

The good news is that due to changes in the regulations we have now been granted a permanent license until the end of 2035. On January 2, the beacon on 40,071 was back on air! In addition, we have solved our interference problems and found a sponsor to cover the license fee for the 40 MHz beacon. So if no other problems arise the 40 MHz beacon of OZ7IGY has now become reliable 24/7/365! 

On behalf of the OZ7IGY-team - Vy 73 de OZ7IS, Ivan.

* * *

For more information on the OZ7IGY beacons or if you would make a financial donation to them then visit their website... http://www.oz7igy.dk/

For more information on the 8m band, see the 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html

Various antennas for the suite of OZ7IGY beacons

2020 Report for the 40-MHz OZ7IGY beacon

In this post, we'll look at the OZ7IGY beacon in Denmark which transmits on 40.071 MHz and how many times it was spotted on the DX Cluster in 2020.

A total of 16 stations spotted the OZ7IGY beacon on 40 MHz during 2020 and the number of spots per individual was... 9A2SB (1), 9A6W (9), DK7UK (2), EA3ERE (13), EI3GYB (10), EI4GNB (1), EI4KP (13), EI7GL (44), EI7HBB (13), F1EIT (13), F6HTJ (4), G0LUJ (5), G7CNF (1), IK0OKY (7), ON4TA (1) & OZ1BNN (9).

As the map shows above, most were in the region of 800 to 1200kms from the beacon which is a typical distance for Sporadic-E signals at 40 MHz during the Summer season.

It's interesting to look back through the years and see just how stations spotted the OZ7IGY beacon each year.

The OZ7IGY beacon first became operational on 40 MHz back in 2007 and a total of 44 individual  stations spotted it on the DX cluster that year. It was probably widely reported in the amateur radio press at the time as it was a beacon for a new band and quite a few people would have been curious to see if they could hear it.

Over the next few years, the only other signal on the band was the GB3RAL beacon which was operational from 2007 to 2014. There were also times when OZ7IGY was non-operational. The lack of any other developments in countries in Europe in getting access to the band didn't help with the level of interest in the new 8-metre band. 

This finally changed in 2018 when radio amateurs in Ireland got access to the 8m band and that kicked off some renewed interest across Europe.

In 2020, 16 individual stations reported the OZ7IGY beacon on the DX Cluster, the same as 2019. The main difference was that only one OZ (Denmark) station was putting up spots in 2020 compared to six in 2019.

As for the number of individual spots for OZ7IGY on the DX cluster, this is the distribution since it started...

The number of spots for 2019 and 2020 suggests that the few who are listening on the band now are more active in contrast to 2007.

Curious Fact... As of the end of 2020, there are a total of about 500 spots for the OZ7IGY beacon since it first became operational on 40 MHz in 2007. Out of all of the spots, there isn't one from outside Europe. There are no double hop Sporadic-E reports. There must have been plenty of times when the 40 MHz signal was audible in North America and South Africa.

DX Cluster... If you do hear the beacon then make sure to report it on dx-clusters like DXSummit or DXMaps as some of the other clusters ignore spots for 40 MHz as they assume they're a mistake.

More information about the OZ7IGY beacon can be found here... http://www.oz7igy.dk/

For more information on the 40 MHz band, go to this page... https://ei7gl.blogspot.com/p/40-mhz.html

Reception of the OZ7IGY beacon on 40 MHz - Fri 6th July 2018

Both 28 MHz and 50 MHz were wide open on Friday the 6th of July 2018 with plenty of strong Sporadic-E signals on the bands. One of the best things about monitoring FT8 signals on 28 MHz is that I can get a very good idea of where the band is open to.

Since I started listening in mid-May, the 28 MHz band has been open every day but openings from Ireland to Denmark are the exception rather than the norm. Openings from Ireland to the South to Spain / Portugal or the South-East to Italy/Germany seem a lot more common.

Today was an exception and as soon as I saw FT8 spots from near Copenhagen on 28 MHz, I listened on 40.071 MHz for the OZ7IGY beacon.  As can be see from the decoded PI4 spots below, I was hearing the 40 MHz beacon from about 13:20 UTC till 21:00 UTC with some gaps.

The 40 MHz signal was never that strong although my use of an indoor 50 MHz antenna probably has a lot to do with that.

This is currently the only signal in Europe on the 40 MHz band.

OZ7IGY beacon decodes below... (Signals stronger than -10dB sigal to noise ratio in bold)