Meteor scatter experiment with the 2023 Geminid shower

In this post, I'll outline how I used an amateur radio beacon 500kms away to find the peak of the 2023 Geminids meteor shower and what else I noticed.

Introduction... Back in 2022, a new radio beacon called GB3MBA was put on air on the 50 MHz band and its primary purpose was carrying out meteor scatter experiments. Located near the town of Mansfield in the centre of England, the beacon runs 75-watts into a small Moxon antenna which beams straight up.

Unlike most amateur radio beacons, this one is basically a carrier that is on nearly all of the time which is exactly what is needed for meteor scatter experiments. The main coverage area is the UK itself but as I'm 502 kms from the beacon, I'm close enough for it to be of use.

I expected that most of the signals that I would hear would be from meteors burning up over Wales and would be arriving at my location about 20 degrees above the horizon.

Experiment Objectives... This is what I wanted to do...

• Carry out an experiment as a 'proof of concept', take measurements, gain experience and see how I could improve on it.
• Take 'hard measurements' with real data as opposed to just forming an opinion.
• See if I could plot and find the peak of the 2023 Geminid meteor shower as a form of 'citizen science'.

Methodology & Equipment... For the previous few days before the peak, I was listening to meteor bursts from the beacon to establish the best method to carry out the experiment.

Radio... I was using an old Kenwood TS-690 amateur radio transceiver which still works fine and is pretty sensitive. I tuned it to 50.408 MHz and set the mode to CW. It drifts a few Hz with the changes of temperature in the shack but it was fine for this experiment. I just needed to be careful to make sure I was always on frequency.

Antenna... In the run up to the experiment, I used a 2-element Yagi in my attic beaming 120-degrees (east-south-east) to get ready. This was beaming about 45 degrees away from the beacon and being indoors, it wasn't optimum. Just before the experiment, I built a vertical T2LT (flowerpot) half-wave antenna and mounted it about 6-metres above the ground. It had a clear view of the sky towards Wales and the beacon.

Software... I used the SpectrumLab programme to look at the audio spectrum so that I could see any bursts and pings of signal. Under the 'Quick Settings', I used Slow Morse Reception ("QRSS") and I then selected 'Slow CW, 30 sec/dot'. 

I knew it wasn't practical to look at a screen for hours on end. At this setting, the audio spectrum is about 30 Hz wide and it takes about 1h 20m for the signals to drift from right to left across the screen. What this meant in reality was that I could look at the screen every 60-80 mins, count the signals on the screen and record the number of pings and bursts.

What to record?... I knew whatever I did, it had to be consistent for the observing period. I decided to use the number of signals seen in a 30-minute period. If it was a long burst or a short ping, I counted it as one signal. 

This raises the obvious question... should I count the number of pings and bursts, should I record the strong signals versus the number of weak signals? The problem is where do I draw the line? I knew I'd see long bursts, short pings and everything in between. It was the same for the signal strength... what's a 'strong signal'? 

I decided I just wanted 'hard data'. Was there a meteor scatter signal present on the screen... Yes or No. It's simple and there's no ambiguity.

Time period... For the experiment, I counted the number of meteor scatter signals from 17:30 UTC on the 14th of December to 22:00 UTC on the 15th of December 2023...a period of 28 hours and 30 minutes. This time frame coincided with the predicted peak of the Geminid meteor shower.

Results... This is the chart that I generated for the 28.5 hour period.

The recording period starts at 17:30 UTC on the 14th of December when the Geminid constellation and radiant point would be just above the horizon. I'll break down the chart in more detail below but the key thing to note is the peak at about 20:00 UTC on the 14th of December.

I had intended to stop recording early in the morning of the 15th but I was wondering if the peak was really the peak? Would there be another peak 24-hours later when the radiant point would be at the some position in the sky? As you can see, there was no peak 24-hours later. I had actually recorded the peak of the Geminids on the 14th.

Results - Time Frame - 17:30 UTC 14th Dec to 05:30 UTC on the 15th of December... The peak, the dip and the highest radiant...

The first 12-hours is shown above in more detail.

The start... I did a search on Google and it said that the constellation Gemini would rise above the horizon in London at 17:23 UTC. I'm 8.5 degrees west which means it would be 33 mins later... 17:56 UTC. The mid point might be say 17:39 UTC? I found another website which said that the radiant point would rise around 16:07 UTC??

This is further complicated by the fact that we're really looking at a time when meteors from radiant point in the Geminids would be hitting the atmosphere 100kms about Wales? I think 17:30 was a good enough time to start.

The peak... Between 19:00 and 20:30 UTC, I had counts of 15, 19 & 21 for each of the 30-minute intervals.

This is a screenshot I took during this period.

First, I'll explain what you are looking at. The vertical axis is a 30 Hz wide segment of the audio spectrum. The screen is moving from right to left and the white dotted lines are the 5-minute time intervals.

If I was hearing the beacon signal directly, it would be a solid yellow line running from right to left across the centre of the screen.

What you are looking at are the pings and bursts of meteor scatter signals which are spread out across the audio spectrum due to doppler shift.

Prior to the shower, I had seen that the peak was expected at 19:30 UTC on the 14th of Dec. Looking at my screenshot, I think the peak of the 2023 meteor shower occurred between 19:55 and 20:20 UTC on the 14th of December.

The dip??... I did make a note of how weak the reflections were from 22:30 and 00:00 UTC and this can be clearly seen in the chart above. 

As the meteor shower radiant moves slowly across the sky, the angles between the transmitter, receiver and the trails of the meteors will change. At some points, the meteor trails will be parallel between my location and the beacon and at other points, the trails will be perpendicular.

I suspect the dip is due to the geometry of the meteor trails but I'm not sure. It could also be just a statistical error. I would need to repeat the observations on several days around this time period to see if it repeats.

Maximum elevation... At about 01:30 UTC, the radiant point was supposed to be at its highest elevation which was about 71 degrees above the horizon.

Before the experiment, I was wondering if this mattered? Would there be some sort of peak when the radiant peak was at its highest point in the sky? The answer seems to be no, there is no peak.

Results - Time Frame - 01:30 UTC to 11:00 UTC on the 15th of December... The daily morning peak...

When it comes to random meteors entering the atmosphere, the best time for signals tends be around 6am local time. This is because the speed of the earths rotation is added to the speed of the meteors resulting in more energy to dissipate.

This enhancement can be clearly seen in the chart above. It increases after 02:00 UTC and decreases after 10:00 UTC. For me at least, it seemed to be an eight hour window.

The converse is also true. At 6pm local time, the speed of the earth's rotation is subtracted from the original speed of the meteors.

This means that the peak of the 2023 Geminids at about 20:00 UTC happened just two hours after 6pm for me which isn't a great time.

As I was looking at the original chart with the 28.5 hour display, I realised that I was looking at two peaks but both were completely different. One is a fixed peak and the other is a variable peak.

The fixed peak was the peak of the Geminids at about 20:00 UTC on the 14th of December. That's fixed, the peak is the peak.

The morning peak however will depend on where you are. Somewhere in the world, the peak of the Geminids meteor shower will coincide with 6am local time. That turns out to the western half of the Pacific. Anyone in say Hawaii, Alaska, Korea, Japan, east China and the Philippines should have seen some very good meteor bursts and pings. That is of course conditional on having the radiant point above the horizon and that will depend on the location.

Results - Time Frame - 09:00 to 22:00 UTC on the 15th of December... This is the last 13 hours of the plot in more detail...

The radiant point for the Geminids sets about 10:00 UTC and a drop in numbers can be seen. The signals from about 10:00 to 17:30 UTC are random meteors and are not Geminids as the radiant point is below the horizon.

You can see it was particularly poor from 16:30 to 17:30 UTC. Then the Geminids radiant point comes above the horizon and the numbers increase again.

Other observations... Aircraft Scatter... I've seen plenty of aircraft scatter on signals before but I was really surprised to see it on a signal from 500kms away.

These can be very easy to miss. On the QRSS 3 setting, these appear as almost horizontal lines due to the larger vertical scale and faster scrolling speed. On QRSS 30 as used above, the slant becomes a lot more obvious.

As you can see, the doppler shift is in the region of 5-7 Hz. When I was seeing these signals appear, I would check FlightRadar 24 and sure enough, there was often a large plane to the west of Aberstwyth on the west coast of Wales. This is around the halfway point from the beacon to my location.

This suggests to me that while the GB3MBA beacon is 'beaming straight up', there is plenty of RF heading towards the horizon as well.

You'll notice as well that the trails last for about 90 seconds which should be enough for digital modes like MSK144 or possibly FT4? I'd have no doubt that a lot of those one off FT8 decodes on the 10m and VHF bands that people get are due to aircraft scatter like this.

Additional Notes...

• I couldn't tell if any meteor heard was a Geminid or not for the time the radiant was above the horizon.
• Despite all of the 'streaks' visible on the screen, the signals were actually pretty weak. Many were not audible to my ear and I'd say the strongest signals were probably something like 519. 
• The process that I used was very labour and time intensive. I literally had to set an alarm to wake up every 60-80 mins overnight and take the measurements.
• My resolution was 30 mins which may have limited the resolution in that I couldn't tell if two very close bursts were one or two.

In Conclusion... I think the experiment overall was a success. I was able to see the peak of the 2023 Geminid meteor shower which was from 19:55 to 20:20 UTC on the 14th of December.

I'm sure there is room for improvement but I think this is a useful 'citizen science' project which can be done by anyone with a good receiver and antenna. This method is also easy enough that it's not restricted to those from a radio background. 

Anyone with a serious interest in astronomy and meteor research could do this and consider it as an additional tool. This system works regardless of the weather. While 'visual' amateur astronomers need clear skies, the 'radio' based amateur astronomer can carry on regardless.

It might make an excellent project for an astronomy or radio club and maybe give a presentation to students as part of a STEM outreach programme

I think it proves that GB3MBA is indeed a very useful beacon for meteor scatter research and I think the challenge now is for them to make more people aware of it.

You can tell from the length of this post that this was a deep dive down the rabbit hole for me. As soon as I had one question answered, I thought up of two more additional questions.

The future??.. I'd see these as areas for improvement.

1. My antenna was a vertical half-wave which is omni-directional. I think something like a 3-element Yagi would give me at least 6dB more gain, reduce noise and result in more pings and bursts.
2. My experiment was for 28.5 hours with a resolution of 30 mins. I think in the future, I would use QRSS 3 with a finer resolution of 10 minutes and plot the period around the predicted peak in more detail.

More information...

For more information on the GB3MBA beacon, go to https://ukmeteorbeacon.org/

There is also the BRAMS beacon in Belgium on 49.970 MHz which might be of interest... https://brams.aeronomie.be/

New WSPR receiver from RemoteQTH

RemoteQTH is a small company in the Czech Republic and they have just announced the release of a new receiver for WSPR. 

It can be used from 0.1 to 28 MHz and is described as follows..."The openWSPR receiver is a stand-alone HF receiver for WSPR. Just connect an antenna, internet and a DC power supply and you're ready to go! With this tiny receiver you can decode and relay WSPR messages to WSPRnet.org. 

Since the entire project is open source, receivers can be easily reprogrammed to receive signals other than WSPR. The nanoPi board inside runs Raspbian OS and several user programs, which are automated by custom scripts, making the receiver completely maintenance-free."

It is selling for €125 which at first glance sounds expensive but I guess one of the main features of this WSPR receiver is that it doesn't require an external PC or computer to run. All of the decoding is done inside the unit. All you need to do is connect the various cables, configure it, connect an Ethernet cable and it uploads the spots to WSPRnet.

Looking at the size of the box relative to the SMA or Ethernet connector then it's really small and just a few cms across.

Future products... They are also developing a separate transmitter module.

They have no information on this in terms of power output but 200 milliwatts seems to be the norm.

It's also interesting to see that they are developing a series of band pass filters...

I think these will be attractive to users of other WSPR products as well as all you need are the connecting SMA patch leads.... no construction, soldering or winding of torroids. 

The photo above shows the surface mount components inside the filter.

Nearly all of these low power WSPR transmitters have a square wave output and require some sort of filter to remove the higher harmonics. This is usually done with a low-pass filter rather than a bandpass filter which tends to have slightly more loss.

Where bandpass filters shine is with the receiver module as they keep all of the potentially large signals on the lower bands out of the front end of the receiver. I think these standalone filter modules may be of interest to anyone with a SDR receiver and who want to concentrate on one band.

Link... More info on the RemoteQTH website

Disclaimer: Just to clarify, no-one paid for this post or sent any product to me for review. These are new products that I think people will be interested in.

Addendum: Since putting up this post, someone hs asked about whether the receiver can hop between bands? Does it run WSJT-X? And what is the performance of the receiver?

I looked at the files section of the site and found a circuit diagram. The receiver schematic shows the input RF going straight into an IC without any preceding RF stage amplification. This might be ok on the bands on the lower bands like 40m or 80m but is it going to be sensitive enough on bands like 10m / 28 MHz?

The input has a single LC parallel circuit which suggests that it is intended for single band use. If these components are left out then an external band pass filter is required for each band.

Two new DX-peditions planned for Bouvet Island...

Back in February of 2023, we had the 3Y0J expedition to Bouvet Island in the South Atlantic which promised a lot but disappointed many.

The initial ambitious plan was to be have 12 stations active for most of the month of February 2023 with a target of 200,000 contacts. In the end, the number of contacts that were actually completed was 18,833 which is 9.4% of the target planned.

In a previous post, I outlined how each QSO might have cost in the region of $38.

After the expedition, there was a lot of talk about how unruly the pile ups were and there were a few soft interviews with members of the expedition about how it went.

What I think a lot of people and groups who donated to the 3Y0J expedition will be wondering about is  the actual planning. 

• How was it that after raising $715,000, they seemed so ill-prepared to transfer equipment from their boat onto the island in what were always likely to be choppy seas?
• Why did they bring four diesel generators that weighed 113 kgs (250lbs) each instead of smaller and lighter petrol (gasoline) ones?
• How did they manage to lose a tent?
• Did they train for the landings on some safe island?

If you were following the expedition then you'll remember that they failed to get the heavy diesel generators off the main boat and had to use just one smaller petrol generator instead which had a limited fuel supply of 50 litres.

The second video below describes some of the problems they faced.

Two videos of the 3Y0J expedition...

Two new expeditions... On the 7th of December 2023, the organisers of the 3Y0J team announced that they were planning to return to the island in 2025 using the call 3Y0K.

Just days later, a rival expedition announced that they were planning a separate expedition as 3Y0I! It looks as if there might be a bit of tension between the two groups... see below.

3Y0K... The key points of their press release were...

• Seeking donations in the order of $150,000
• A much reduced team of 3 operators instead of 12
• The use of remote operation
• Equipment reduced to 2.1 tons from 7 tons.
• 21-days on the island
• Use of light weight Honda generators
• More dinghies

You can read their press release HERE

Website... https://3y0k.com/

3Y0I... The Rebel DX Group release this statement just days later...

"BY REBEL DX GROUP 

Due to Dom 3D2USU being kicked out of the 3Y0K Bouvet DXpedition / Project which was made and led by Ken LA7GIA and Dom (Ken was informed by DX foundations that if he joined forces with the Rebel DX Group there would be no support for Ken), the Rebel DX Group has decided the time is right to reactivate 3Y0I plans and stage their own DXpedition to Bouvet. You may remember that in 2019, the 3Y0I team were unsuccessful in getting to Bouvet due to inclement weather, seas and vessel damage. 

For this DXpedition, there will be no support or funding needed. They seek no assistance from foundations or clubs. All equipment is in place already in South Africa. Plan is for three operators to land on Bouvet with an additional five more ops operating CW remotely – more on this in the future.

A vessel has already been secured and will be operated by four ex-Navy seals from Military Unit Formoza. A captain and first mate will complete the team – between them they have 25 years experience heading into the cold South Atlantic waters. Many years ago, Dom 3D2USU, landed several times on Bouvet using a dinghy during a 3-day stay.  The whole crew is highly trained for this kind of landing and surviving in harsh conditions.

Reissuing the 3Y0I license is straightforward. You can get your own license if you wish. It takes two days and $0 dollars to receive one.  Some info will not be provided for many reasons – for example dates will only be announced near the time of sailing. 

As a footnote, the last 2.5 years the Rebel DX Group has delivered over 1 million QSOs from various Pacific islands. LoTW is always uploaded straight after any expedition, without delay or requests for “Express LoTW” services. QSL cards from the Pacific are usually sent out once a year when the team is back in Europe to print them, and then take back to Fiji. Note:

QSL cards from Bouvet will be run by proper QSL manager as we will relocate our team to another cold place. More on that info soon."

HF Conditions... As someone pointed out on Twitter / X, we're near the peak of the sunspot cycle and things will start to get worse in the next few years on the higher HF bands like 28 MHz as we move away. Whoever gets to Bouvet, it would be better to be operational as soon as possible.

Geminid meteor shower peaks on the 14th of Dec 2023

The Geminid meteor shower is one of the biggest of the year and meteors from this shower should appear from the 4th to the 20th of December. The peak is predicted to be at 19:30 UTC on  Thursday 14th of December 2023.

The radiant of the shower is above the horizon from about 18:00 to 10:00 local time and will be highest above the horizon around 02:00 local time. As the sky will be dark with a new moon, it should be a good visual spectacle as well in clear skies.

From a radio point of view, there should be plenty of meteor pings and bursts with an hourly rate of 150 expected.

On bands like 40 MHz, 50 MHz & 70 MHz, signals that are 500-1000kms distant should give good signals. The higher bands like 144 MHz will need longer paths.

One of the best bands for meteor scatter is 50 MHz. See if there is a beacon about 500kms from your location and have a listen on SSB or CW. It can be useful to have a waterfall display like that used for FT8 so that you can visually see weak signals.

The best time for meteor scatter is usually around 6am local time. If you were to try around 6am on the 14th & 15th of December then you should see and hear plenty of meteor bursts and pings.

W5LUA gets first Worked All States award for the 903 MHz - 33cms band

Radio amateurs in the USA have access to an unusual band at 902 to 928 MHz which is known as the 33 cm band. Due to its unusual nature, much of the equipment for the band has to be home made or modified with transverters being a popular choice.

In November of 2023, Al W5LUA was awarded the very first Worked All States award from the ARRL. He started collecting the states shortly after the band opened in 1985 and his quest has taken 18-years.

As a band in the UHF region, most of the 'local' states would have been possible via tropospheric propagation but to work all 50 US states, signals had to be bounced off the moon. i.e. EME or moonbounce.

W5LUA's station consists of a 5-meter dish with 400 W of power obtained from two 300 W Motorola amplifiers in parallel. His feed is a dual polarity patch feed.

As recently as September of 2023, W5LUA was stuck on 32 states and still 18 short. Thanks to Peter, KA6U who went on a roving 25-state expedition, the last 18 states were worked.

W5LUA writes... "I am extremely grateful to Peter Van Horne, KA6U, for his EME [Earth-moon-Earth] efforts. I was able to work Wisconsin for my last state on the 33-centimeter band on October 21. At the end of September, I was sitting at 32 states confirmed with cards and/or the Logbook of The World (LoTW), when Van Horne went on a 25-state expedition providing my last 18 states." 

W5LUA also notes that prior to that, recent expeditions by Brian, NX9O, and Jason, N1AV, also provided several states that were needed.

Background to the 33 cms band... In 1985, the FCC allocated the frequency band between 902 and 928 MHz to Part 18 industrial, scientific, and medical (ISM) equipment. In that proceeding, the band was also allocated to the Amateur Radio Service on a secondary basis, meaning amateurs could use the band if they accepted interference from and did not cause interference to primary users.

The list above from the North Texas Microwave Society gives an idea of what equipment is used on the band.

Links...
1) ARRL... The First Worked All States Certificate Awarded for the 33-Centimeter Band.
2) North Texas Microwave Society... 902 MHz Presentations (PDF)

The 'Morse Phone' Oscillator Kit

I recently came across this morse code oscillator kit which some clubs or beginners might find of interest. While it is designed for JOTA (Jamboree on the Air for Scouts), it would be useful for say a radio club or Maker group to get experience of building an electronic kit with through hole components.

Steve, EI5DD in Co Galway in the west of Ireland did exactly this. Steve writes... "A few morse practice oscillator kits built over the weekend for our local scouts group following the interest during Scouts Jamboree on the Air."

A close up of the kit is shown above and it should be pretty easy to build. The 'morse key' is made out of a piece of PCB which is used as a lever / switch.

The image above shows a side view of it. The website that is selling the kit has a detailed PDF document where all the construction details and the schematic are shown.

This is the link for the kit... https://www.kitbuilding.org/index.php/en/webshop-en/electronic-kits/the-morse-phone-2017-detail

Please note that I have no connection with this site or the kit. I didn't build it and it wasn't sent to me for review. I just noticed that Steve, EI5DD bought a batch of them and it helps promote the use of morse code / CW.

Promising news for the amateur radio 23cms microwave allocation - Nov 2023

With the development of GPS and other radio navigation satellite systems, the part of the radio spectrum above 1 GHz has become very attractive and this has put pressure on the 23cms / 1.3 GHz amateur radio band. For the last few years, it looked as if the decades old allocation might be lost altogether.

The International Amateur Radio Union (IARU) are now reporting that an agreement has been reached for a recommendation for 23cm band amateur operations to be allowed on a non-interference basis alongside the co-frequency radio navigation satellite service (RNSS). The recommendation from the the ITU‑R Radio Assembly (RA) will form a component of the WRC-23 discussions which are ongoing until December 15th. (see update below)

While the threat to the 23cms band hasn't been removed completely, it is significant that a technical sub group has reached an agreement and hopefully it will be approved at the main conference.

***

Update - 8th Dec 2023: 23cm band outcome approved at the 7th Plenary meeting of WRC-23

The following was posted today on the IARU web site: During the WRC-23 deliberations, strong positions were expressed by all the parties involved. The result is a well-supported compromise for a footnote in the Radio Regulations regarding amateur and amateur satellite service operation in the 1240 – 1300 MHz range. The footnote reminds administrations and amateurs of the need to protect the primary RNSS from interference and provides guidance to administrations to allow both services to continue to operate in this portion of the spectrum. The compromise was formally adopted by the Conference Plenary on December 8 and is not subject to further consideration during the final week of the WRC. The IARU team continues its work on other WRC issues including the development of agendas for future conferences.

IARU President Tim Ellam, VE6SH, noted “This is a very good result for the amateur services. The decision reached at WRC-23 on this agenda item makes no change to the table of allocations nor incorporates by reference M.2164 into the Radio Regulations. The addition of a footnote that provides guidance to administrations in the event of interference to the RNSS is a good regulatory outcome for amateurs and the primary users of this band.”

***

The image above from the IARU gives a good overview of what is going to happen to the 23cms amateur radio band.

1) Parts of the band restricted to just milliwatts... The current band is 60 MHz wide going from 1240 MHz to 1300 MHz. There will be a severe power restriction for large segments of the band that might overlap the radio navigation satellite signals.

Example...The section of 1240 to 1255.76 MHz overlaps the Russian Glonass system, Here, just 1.26-milliwatts in a 150 kHz wide signal is allowed. Note that this is effective radiated power so it includes any antenna gain. In simple terms, this prevents any amateur use of these segments of the band.

2) Protecting the DATV segment... The key target for the IARU has been to protect the main centres of activity and one of these is the Digital Amateur TV segment around 1260 MHz. The frequencies below are from the current IARU Region 1 band plan...

1243,250 - 1260,000 * (D)ATV 1258.150 - 1259.350 Repeater output

There will be power restrictions in terms of EIRP (combined power and antenna gain) and the IARU gave these examples...

1255.76 to 1256.52 MHz (760 kHz) = 250W eirp... 4W into typical beam antenna (18dBi) or 60W into 6dBi mobile ant.

1256.52 to 1258 MHz (1.48 MHz) = 125W eirp...2W into typical beam antenna (18dBi) or 30W into 6dBi mobile ant.

3) Protecting the narrowband segment... The other important part of the band from an amateur radio point of view is the segment for narrowband modes from 1296 to 1300 MHz (e.g. CW, SSB, FM, FT8). Here, the plan is for a simpler power output restriction rather than taking the antenna gain into account as well.

1296 – 1298 MHz = 50W pep into antenna & 1298 – 1300 MHz = 150W pep into antenna

There is a higher power limit for moon bounce operation as long as the antenna has more than 30dBi gain and is pointing more than 15 degrees above the horizon.

4) Amateur Radio Satellites... There is a complex set of power restrictions covering narrowband operation in the amateur satellite band from 1260 – 1262 MHz. These range from very low power at low elevation angles to higher power levels at high angles (−3 dBW for 0° to 15° / 17 dBW for 15° to 55° / 26.8 dBW for 55° to 90°).

I'm not aware of any amateur satellites using these frequencies or if any licensing authority will be keen in the future to give permission to any potential new satellites considering the contested nature of the band.

23cms / 1296 MHz... Why does it matter??? AMSAT UK sums it up nicely... "The 1240 – 1300 MHz band is important for the amateur radio service, being the lowest allocation for radio amateurs on which typical microwave propagation can be experienced. Access to these frequencies is facilitated by commercially available equipment and provides a ‘bridge’ building motivation to become involved in more specialized higher frequency microwave and millimeter wave operations providing the self-training which is at the heart of amateur radio."

In conclusion... As the IARU notes..."The final recommendation represents the culmination of more than 4 years of work by the IARU team within the ITU‑R study groups to ensure the best outcome for amateur radio in the face of intense regulatory, political and commercial pressure."

Some people may be disappointed with some of the proposed changes but there really isn't another alternative. The choice here is pretty simple... either the amateur radio service can co-exist with radio navigation satellite systems in the 23cms band on a non-interference basis or have no amateur allocation there at all.

If the plan is agreed at the conference as expected then it offers some certainty to radio amateurs who want to use the band, They can buy or make equipment safe in the knowledge that the band won't be gone in a few years time.

It also allows the radio amateur service some protection in that we can hide under the protection of these radio navigation satellites. It's highly likely that the various governments would have serious objections to any commercial interests trying to get access to the 23cms band in the future.

Further reading... You can find more information at the links below...

1) Potential Interference To Galileo From 23cm Band Operations ...by Peter Blair, G3LTF (2005) 

2) 23cm band in the spotlight with regulators... AMSAT-UK (Feb 2021)

3) 23cm Band and RNSS Coexistence September Update... AMSAT-UK (Feb 2021) 

4) Austria restricts 23cm band operation... AMSAT-UK (March 2023)

5) ITU‑R Recommendation M.2164 on 23cm amateur service and RNSS operations now published in time for WRC-23 discussions ...IARU (Nov 23, 2023)

6) ITU-R M.2164 Summary ...IARU (Nov 23, 2023) 

7) Recommendation ITU-R M.2164-0 : Guidance on technical and operational measures for the use of the frequency band 1240-1300 MHz by the amateur and amateur-satellite service in order to protect the radionavigation-satellite service (space-to-Earth) ...ITU (Nov 23, 2023) 

8) IARU Region 1 band plan for 23cms ...IARU (March 2021)

Addendum...After I put up this post, the RSGB released this related video which was made in October 2023 (1h 42m in length)...

1. Barry Lewis, G4SJH talks about "Amateur/RNSS coexistence in the 23cm band"
2. John Worsnop, G4BAO considers "How will the possible RNSS changes affect narrow band DX operation and EME?"
3. Dave Crump, G8GKQ looks at "The future of ATV in 23cms"

F2 Skip Zone on 28 MHz - 7th Dec 2023

As the WSPRnet website was down for most of today, I left the radio on the FT8 frequency of 28.074 MHz instead. As expected, there were a lot more signals on this mode.

One thing that stood out after a few hours was the skip-zone as shown in the map above. There was no sign of any real Sporadic-E and nearly all of the signals that I heard were coming off the F2 layer of the ionosphere.

The closest signals to the south-east were front central Italy around the 1700km mark. At this distance, the signals were probably coming in to my location about 25-degrees above the horizon. Anything closer than this resulted in a higher angle and propagation wasn't possible.

To the north-east, the closest stations were about 2300kms in the north of Sweden with no sign of anyone closer.

It's also interesting to note that all of Spain is missing, even the far south of the Iberian peninsula is too close for 28 MHz propagation today.

Impressive rollout of DAB+ network in France

I recently noticed that a new DAB+ radio network is being rolled out now in France. Broadcasting by radio is seen by many as a thing of the past and here we see a new radio network being installed in one of the largest countries in western Europe.

The traditional FM radios on Band 2 use 87.5 to 108 MHz with one station per frequency. The new DAB+ system uses Band 3 which goes from 174 to 240 MHz and has several stations grouped together on something called a multiplex. This allows for more stations to fit on a given band and more crucially, it allows space for new stations to enter the market.

By October of 2023, the French DAB+ covered the Paris-Lyon-Marseille corridor taking in all major urban areas along this route (shown below in purple).

By the end of March 2024, they hope that 60% of the population as shown above will be able to receive DAB+ radio stations.

As far as I know, no date has been set for any switch off of the 88-108 MHz FM broadcast band and I suspect both will co-exist for quite some time.

Link...
1) French DAB network... https://www.dabplus.fr/

Launch & Deployment schedule for EIRSAT-1

EIRSAT-1 is the first Irish satellite and I covered this in a previous guest post by Lez, EI4GEB.

The cubesat is going to be launched with 24 other satellites on a SpaceX Falcon 9 rocket from the Vandenberg Space Force Base in California at 18:19 UTC on Friday 1st December 2023.

Other satellites on board include KOREA's 425, Space BD’s ISL48, SITAEL’s uHETSat, D-Orbit’s ION SCV Daring Diego, York Space Systems’ Bane, and PlanetIQ’s GNOMES-4. This is also the 17th flight of the first stage booster supporting this mission, which previously launched Crew-1, Crew-2, SXM-8, CRS-23, IXPE, Transporter-4, Transporter-5, Globalstar FM15, ISI EROS C-3, and seven Starlink missions. Following stage separation, the first stage will land on Landing Zone 4 (LZ-4) at Vandenberg Space Force Base.

Sequence of events... Here is a timeline of what is expected to happen...

18:19 UTC - T=0 - Launch of Falcon 9 from California.

19:49 UTC - T+90 mins - EIRSAT-1 injected into a 520-km Sun-Synchronous Orbit somewhere over Norway.

20:34 UTC* - T+135 mins - Satellite’s antenna deployment somewhere over the South Pacific.

20:45 UTC* - T+146 mins - EIRSAT-1 will pass to the south of New Zealand & Australia. Is it in range? If it is, it's likely to be very low in the southern sky.

20:58 UTC* - T+159mins - EIRSAT-1 will pass over South Africa. 

21:18 UTC* - T+180 mins - EIRSAT-1 over Europe

*Approx

Frequencies...

EIRSAT-1 is not a communications satellite and does not relay signals. It has a number of experiments on board and it will transmit telemetry back to earth on the 70cms UHF band, at a frequency of 437.100 MHz. 

The downlink is GMSK modulated at a data rate of 9600 bps. Instructions for decoding the EIRSAT-1 beacon are available on the EIRSAT-1 instruction page.  

Doppler Shift... As EIRSAT-1 will be traveling at about 27,000kms per hour, there will be a significant amount of doppler shift on the signal at 437 MHz. The amount of doppler and how fast it changes will depend on whether the satellite is going directly overhead or is passing to the east or west and not too far above the horizon.

As a guide, you should tune to 437.110 MHz to first hear the satellite. As you track it, it will move down in frequency and it should be down around 437.090 MHz as it moves out of range.

See the website of VK3JED for some examples.

QSL Card from the European Space Agency... The first confirmed recording of EIRSAT-1 from each continent (Europe, Africa, Asia, North America, South America, and Oceania) within a week of launch will be rewarded with a QSL card from ESA. These “special postcards” confirm that radio contact was made, and will include acknowledgement of the help given by the winners to ESA and the EIRSAT-1 team in acquiring the first signals from EIRSAT-1. 

To enter this competition, please send in your recording, timestamp of passage over your ground station, and the location of your ground station to cubesats AT esa DOT int. Be sure to include “EIRSAT-1 competition” in the subject of the e-mail.

EIRSAT-1 Control Room in Dublin

EIRSAT-1 Experiments... EIRSAT-1 is Ireland’s first satellite, and was designed, built, and operated by students with the support of ESA Education’s Fly Your Satellite! programme. In addition to the radio transmitter, EIRSAT-1 houses three main experiment payloads, which were built from scratch by the student team:  

GMOD is a detector to study gamma ray bursts, which are the most luminous explosions in the universe and occur when a massive star dies or two stars collide.  

EMOD is an experiment to see how a thermal treatment protects the surface of a satellite when in space. 

WBC will test a new method of using Earth’s magnetic field to change a satellite’s orientation in space. 

Video... This non-technical 22-min video intended for the general public gives an overview of how EIRSAT-1 was conceived and built.

Links...

1) ESA- Calling all radio amateurs – be the first to hear satellite EIRSAT-1 from orbit

2) EIRSAT-1 technical data... https://github.com/ucd-eirsat-1/beacon

WSPR activty report for the 28 MHz band - Nov 2023

Every day for the last few months, I have left the radio listening on the WSPR frequency of 28.1246 MHz and I feed the spots up to WSPRnet. Most days, I don't even check what the radio heard, I just leave the radio on so that others can see how far their 10m WSPR transmitters are reaching.

I had a look today at what I heard for the last 5-weeks which is from the 26th of October to the 29th of November 2023. Considering that we're near the peak of the sunspot cycle, this post gives an idea of what what the band was like.

Totals & Distribution... In total, I heard about 1200 individual stations on 28 MHz during the 5-week period. This is a huge change from a few years ago when I would hear relatively few. It's not that conditions just got good but I think a lot of WSPR users came up to 28 MHz from the lower bands. 

There are a few false reports in the 1200 from strange callsigns out in the middle of nowhere but the vast majority of them are genuine.

The map above shows the distribution and it's obvious most of the WSPR activity is centred on North America and Europe. South America is surprising low and there is almost nothing from Africa outside of South Africa. There is however a good amount of activity from Australia.

DP0GVN... I heard the German Antarctic research station DP0GVN a total of 47 times during the 5-weeks. The best times seem to be in the afternoon but I heard it as early as 07:48 UTC and as late as 18:48 UTC.

Japan???... Where is everyone? I know there have been paths from Ireland to Japan on 28 MHz for people using FT8 but I heard nothing on WSPR. I checked some of the reports for some of the Australian stations and these seem to confirm that there seems to very little interest in WSPR in Japan.

North America... This is the distribution of stations in North America. For the USA, this pretty much mirrors the level of activity and population in the country. You can draw a line north from Houston, Texas and a lot of the radio amateurs are to the east of that.

From Ireland, it's pretty easy to hear the eastern half of the USA so it's nice to see all of those more difficult northerly paths to the west coast. This is especially true when I start seeing those VE6's and VE7's in the north-west.

I do have one report of hearing KL2OF in Alaska but I think it was bogus. I only heard it once, QRZ says the call has expired and the signal was only sent for one 2-minute period. 

I'm not even sure if a WSPR path is likely to Alaska from Europe considering the polar flutter on the signal at 28 MHz?

The UK on Backscatter... There are quite a number of stations in England using WSPR on 28 MHz and most of these stations shown above are about 400-700kms from my location. This is too short for single hop F2 layer and they are in my 'skip zone' according to usual propagation textbooks.

There might be some Sporadic-E in there but it's likely the vast majority are F2 layer backscatter. The 10m signal is being reflected off distant objects like mountains and ocean waves 1000's of kms away. It's certainly not aircraft scatter.

France - Où êtes-vous???... The map above shows the distribution of signals from western Europe. WSPR is popular in the Netherlands and Germany but where is all the WSPR activity from France???

It doesn't seem to be just a lack of transmitters either. There seems to be a equal shortage of people in France listening on the band and reporting.

Australia on 10m... It's always nice to see the 28 MHz WSPR signals from Australia coming through and I heard 29 VK stations in the 5-week period. For whatever reason, I didn't hear any VK7 stations from Tasmania.

As can be seen from the chart below, most of these stations are about 15,000 to 17,500 kms from my location.

Note the Signal to Noise reports (SNR). Most are these signals are buried in the noise and below what can be heard by the human ear. That's the magic of the WSPR mode.

WSPR seems to have a niche following in Australia and those guys are doing some interesting work investigating propagation paths on the 50 MHz and 144 MHz VHF bands.

Polar Stern... Nearly all of the WSPR signals are from stationary stations but a few are on the move. The map above shows my reception reports of the German polar research ship Polar Stern which uses the call DP0POL. It went through the English Channel a few weeks ago and made it's way down to South Africa.

Some days, propagation is good and I get a string of reception reports resulting in a blurred line. Some days, I heard it only a few times if t all.

Path of pico-balloon AF6IM

Pico-Balloon AF6IM... The very small balloon AF6IM was launched from California a number of weeks ago and it has gone around the world at least once. See my previous post.

The map above shows where I heard it over the last few weeks.

In summary... As a beacon mode, WSPR won't be of interest to everyone but it's nice to see a good level of interest in the mode especially on the 28 MHz band.

Just for reference, I was using a simple CB type half-wave antenna for this test so nothing special on my side.

Link...
1) The best website to check WSPR reports is http://wspr.rocks/

F2 opening on the 50 MHz band across the North Atlantic - 27th Nov 2023

As we approach the peak of the solar cycle, things are beginning to improve on the 50 MHz (6m) band with some F2 layer propagation appearing.

In general, north - south openings are the first to occur on the 6m band as the conditions improve in the F2 layer of the ionosphere. You'll see reports of openings from the Europe to South Africa and from North America to South America. Nice openings but nothing to get too excited about.

The openings to watch out for are the east-west ones from more northerly latitudes. These paths are much more difficult so it was interesting to see an opening on the 27th of November 2023 from the north-west of Europe to North America.

The image above shows the FT8 paths for EI7BMB near Dublin and it's an example of what the opening was like. It's likely that the path from Ireland to Newfoundland was the only single F2 hop. All of the other longer paths required at least two hops.

The most westerly station was W5LDA in Oklohoma.

The image above shows the 6m paths for K1TOL in the state of Maine. The most interesting paths here are the most northerly ones with an opening to the north of Denmark and the south of Sweden.

The solar flux on the day was 187. This isn't going to be a one-off and there should be plenty more east-west openings on the 50 MHz band across the North Atlantic over the next few weeks. Check around 13:00 to 16:00 UTC.

It'll be interesting to see over the next few weeks if there are any openings from the west coast of the USA to the north of Europe.