Radio quiet site in Scotland required for 50 MHz meteor scatter reception

The GB3MBA beacon near Mansfield in England operates on 50.408 MHz and was set up to investigate reflections from meteor trails.

As the map shows above, the project team has already has a number of dedicated receivers set up to monitor the 6m band for any meteor reflections from the beacon. They are however looking to for a quiet radio site in Scotland for a receiver there.

Brian, G4NNS writes... "What is needed is a reasonably radio quiet site with no nearby 6 m transmissions, with power, (10 W or less) and an internet connection. The data stream is about the same as an audio stream so not excessive. Ideally the site would be a minimum of 200km North of the beacon which is located near Mansfield 53.10N, 1.22W.

An astronomy society with  a dark sky observing site would be ideal. We would need someone local who is radio "savvy" to check the site and help with installation.  A locally sourced mast of 3 or 4m would be handy but we can supply all other materials.  We are trying to achieve a range  of different reflection geometries for each meteor event. When we can make observations from a sufficient number of  different directions it may be possible, by using Doppler measurements, to calculate the trajectory and hence radiant of the meteor."

More information about the beacon can be found here... https://ukmeteorbeacon.org

Reception of the 50 MHz GB3MBA beacon during the Quadrantids meteor shower - 4th Jan 2024

Back in December, I carried out an experiment to find and record the peak of the Geminids meteor shower by listening to the GB3MBA 50 MHz beacon which is 500kms from my location. See post HERE

On the afternoon of 4th of January 2024, there was the peak of the Quadrantids meteor shower which tends to be very narrow but intense. This time, I just took some screenshots of the meteor reflections.

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.

For the Quadrantids meteor shower, I was using a Yaesu FT817 on USB as a receiver and the antenna was a 2-element Yagi in the attic of my house. The antenna was beaming about 120 degrees which is about 45 degrees off the beam heading for the beacon (The choice of beam heading is determined by the space in the attic and I wasn't trying to beam away from the beacon).

Quadrantids screen shots...

The image above shows the composite collection of seven different screenshots. As can be seen, there was plenty of evidence of pings and bursts from the GB3MBA beacon.

The images on the blog are quite small and a link to a larger version of the image is on Facebook HERE.

I'll use the more detailed example above to explain what you are looking at. The time is moving from right to left and you will notice the 30-second timestamps. As my receiver isn't GPS locked, I'm probably around 5 Hz off frequency which is ok. 

If I was hearing the beacon directly, it would show up as a solid yellow line going across the centre of the screen. Instead, you are looking at the signal reflecting / refracting off the trail of electrons left behind by the meteor as it burnt up. As these electrons are in motion in different layers of the upper atmosphere, there is some doppler shift on the signal.

In the example above, the 50 MHz signal lasted for about 90-seconds.

The signal on the far right of the image above is one of my favourites. This is called an 'epsilon' echo as it twirls around. What causes such a complex pattern as opposed to the other 'smudges'?

Link...
1) GB3MBA website

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/

Listening to the EI1KNH 40 MHz beacon during the 2022 Quadrantids meteor shower

The 2022 Quadrantid meteor shower was predicted to peak at 21:00 UTC on the 3rd of January and as an experiment, I wanted to see if I could detect the peak using the EI1KNH beacon on the 40 MHz band.

First, let me set out what I did. The EI1KNH beacon transmits on 40.013 MHz using both CW and the PI4 digital mode. It is 213 kms from my location and is is badly screened by mountains to the south-west of the beacon site.

Using just a 28 MHz vertical antenna, I listened for two 18-hour periods for two days i.e. 18:00 UTC on the 3rd of January to 12:00 UTC on the 4th of January AND from 18:00 UTC on the 4th of January to 12:00 UTC on the 5th of January. For both 18 hour sessions, I monitored the frequency for PI4 signals.

Some of the decodes are shown above so I had some success. This is the distribution of decodes...

The chart with the Blue bars shows the number of decodes on the 3rd & 4th of January and I had 22 decodes in total. There seems to be a peak in the number of PI4 decodes from 02:00 UTC to 08:00 UTC on the morning of the 4th of January.

During the 18 hour period on the 4th & 5th of January, I had just 8 decodes.

Was the experiment a success??? Well... maybe. I came to following conclusions...

1) To do the experiment properly, I should probably have monitored over several days. Maybe something like 2 days before the peak and 2 days after.

2) I don't think PI4 is the best mode for meteor scatter. The PI4 transmission is about 20 seconds in length and many of the bursts heard were quite short. I'm not sure how much of the signal I would need to hear for a valid decode but I suspect I was only getting the really big meteor scatter bursts. As can be seen from the chart, the 'peak' is hardly outstanding. 

3) With the distance around 210kms, I think I'm a bit too close. If I was further away... say 500-1000kms then I think the meteor scatter bursts on 40 MHz would be much better. As I'm only 210 kms, I am also getting some aircraft reflections and I'm not 100% all of the signals heard were actually meteor scatter. The longer distance would also rule out any tropo.

In conclusion: The attraction of PI4 for me was that I could just leave the radio on a frequency and count the number of decodes afterwards. It was a worthwhile experiment but I get the feeling that I was only seeing the 'peak' with a very low resolution. 

I'll probably try some experiments again for a future meteor shower but I'll use a different signal and mode.

Lots of bursts on 28 MHz from Geminid meteor shower - 14th Dec 2021

On the morning of the 14th of December 2021, I noticed a lot of meteor scatter bursts of weak signals from G0MBA and G0PKT on 28 MHz. Both stations are located about 650kms to the east of me and the bursts were due to the Geminid meteor shower.

They are both sending QRSS signals which is very slow morse code which can be decoded visually and they transmit about 400Hz below the WSPR signals on 28 MHz. 

An example of what the signals should look like is shown below. This is from a Sporadic-E opening last May.

I did note this morning that while I was hearing all of these meteor scatter bursts, I was getting no WSPR decodes from either station. This was no great surprise as WSPR signals are nearly two minutes in length and only exceptional meteor bursts are that long even on a low frequency like 28 MHz.

As you can tell from the initial image, signals from meteor scatter look a bit of a mess and I'm sure this doesn't help with decoding either.

I did manage some WSPR decodes from both G0 stations later but I suspect it might have been weak Sporadic-E.

UTC (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km
2021-12-14 08:38 G0MBA JO01 EI7GL IO51tu 28.126066 0.2 -19 -1 645
2021-12-14 09:18 G0MBA JO01 EI7GL IO51tu 28.126067 0.2 -20 -1 645
2021-12-14 09:38 G0MBA JO01 EI7GL IO51tu 28.126065 0.2 -24 0 645
2021-12-14 08:08 G0PKT JO01mt EI7GL IO51tu 28.126078 0.2 -22 0 647
2021-12-14 08:38 G0PKT JO01mt EI7GL IO51tu 28.126077 0.2 -15 -1 647
2021-12-14 09:18 G0PKT JO01mt EI7GL IO51tu 28.126078 0.2 -18 0 647
2021-12-14 09:38 G0PKT JO01mt EI7GL IO51tu 28.126075 0.2 -18 0 647
2021-12-14 12:18 G0PKT JO01mt EI7GL IO51tu 28.126076 0.2 -21 -1 647

28 MHz Meteor Scatter contacts??? ... I wonder if anyone has tried making meteor scatter contacts on 28 MHz with dedicated MS modes like MSK144? Considering how many bursts there are during major showers, contacts in the range of 500 to 1000kms should be really easy.

Guest Post: Experimental reception of the OZ7IGY 40 MHz beacon via meteor scatter ...by S57RW

Andrej, S57RW in Slovenia left the following comment on the blog today under an old post. Rather than leaving it there largely unnoticed, I am putting it up as a short guest post.

* * *

Wednesday 5th May 2021:  Today I tried to listen to beacons on the 8m band and around 09:30 UTC, I got two bursts from OZ7IGY in Denmark. 

Both had a duration of about 10-seconds. First, I got a part of the PI4 transmission but that was not long enough to decode. After 2-3 minutes, I got a second burst and copied part of locator and final carrier.

This one was quite strong about S5 to S7 and had a typical burst and after burst. Don't know if that is the right term but it sounded like typical strong MS burst. 

It may be worth listening in the morning when there are more meteors around :) 

RIG was IC-7300 and a dipole for 8m abt. 4m high N/S direction. 73 Andrej - S57RW!

* * *

As the map shows above, S57RW is about 1200kms from the OZ7IGY beacon in Denmark, an ideal distance for meteor scatter on the 40 MHz band.

Note that the Eta Aquariids meteor shower peaks on the 6th of May.

Meteor explodes over the English Channel (20th of March 2021) - Were there any unusual radio signals??

On Saturday the 20th of March 2021 at approximately 14:53 UTC, a large meteor entered the earths atmosphere and burnt up over the English Channel.

According to a news report on the BBC website, this resulted in a large sonic boom as the meteor exploded.

Massive bang over #Dorchester around 20 minutes ago. Any sound nerds know what it is? #Dorset. pic.twitter.com/tHnHEifhhF

— Ollie Peart (@Ollieep) March 20, 2021

The meteor probably burnt up at a height of about 100kms which meant it would have been visible over quite a large area.

The photo above is from a dashcam on the island of Jersey.

This image from a weather satellite shows a flash over the Bristol Channel. 

Note however how much the photo is distorted which suggests that perhaps the photo was taken from a geostationary satellite over the equator and it is looking at the UK from a low elevation. That 'white dot' may not be actually over the Bristol Channel but it could be maybe 200kms further south. Note that while the clouds in this picture might be say 5kms above the ground level, the flash is about 100kms up.

There are other reports of a meteor burning up over the English Channel.... see HERE

**

Any unusual radio signals???

As this large meteor burnt up at a height of about 100kms above the earths surface, it would have left a trail of ionised gas in its wake.

I know it's a long shot but I wonder if anyone noticed any unusual signals at about 14:53 UTC on the 20th of March 2021?

Example. Were you on a digital mode like FT8 on 28 MHz, 50 MHz or 70 MHz? If your WST-X programme is still running from Saturday then you can go back and have a look. Your logbook of received signals is up on the PSK Reporter website for 24 hours after the event.

Example. Were you listening on the FM band (88-108MHz)? Were you using an SDR receiver and recording the band?

If you heard anything then get in touch or leave a comment.

* * *

Update 25th March 2021: In the hours after the meteor burnt up, I had a look at the PSK Reporter website and looked at some of the FT8 signals that were heard by stations in the UK, Ireland & France on the 28 MHz & 50 MHz bands.

(FT8 is a digital mode where signals are sent in 15 second bursts)

I have put together maps below for several stations. My own conclusion is that there are signs of some meteor scatter activity over the north coast of Brittany and Normandy but I don't think we can be 100% sure about any individual reception report.

I'd suggest that the results show that something happened in this general area but I'm not sure we can infer anything about the exact direction the meteor was traveling.

I have included the time stamps for each of the paths and you can decide for yourself if they are indeed due to this meteor burning up.

See below...

144 MHz signal from the Faroe Islands heard 3000kms away in Bulgaria during Geminid Meteor Shower - Dec 2020

Every year, the Geminid meteor shower peaks around the 14th of December and many VHF radio amateurs make contacts by bouncing signals off the meteor trails left behind. The maximum distance tends to be similar to Sporadic-E i.e. in the region of 2300 kms.

During this years Geminids, Stamen LZ1KU announced a suprise reception on 144 MHz of Jon OY9JD on the Faroe Islands, a distance of 3075 kms!

A composite of the screenshot from LZ1KU is shown below...

As can be seen, the mode used was MSK144 and there is one decode from OY9JD.

On an online forum later, OY9JD did confirm that he was on air at that time...

According to info provided by SO3Z, Jon OY9JD is using an ICOM IC970 with 500W into an 8 el Yagi 3m long. LZ1KU is using an array of 4 x 12 elements and 1.7kW.

Even though there was no two way contact on this occasion, it is still an impressive distance for 144 MHz. Remember that 3075 kms is roughly the distance across the North Atlantic between Ireland and Newfoundland.

In fact, 3075 kms to the west from OY9JD actually reaches the remote areas of Labrador in NE Canada.

Mode of Propagation??? (Updated)... 

(Theory 1) Double Hop Meteor Scatter... Most meteor trails capable of supporting propagation of 144 MHz signals last for a fraction of a second at best with the occasional one lasting several seconds.

Was it a case that that on this particular occasion, two meteor trails were in just the right spot happened at the same time?

In other words, the MSK144 signal from OY9JD was reflected off the ionised trail of one meteor, then hit off another trail several hundred kms later and then was picked up in Bulgaria.

As you might imagine, this isn't that common as it requires there to be two meteor trails to be just in the right place and at just the right time.

(Theory 2) Tropo Assist?... As for did tropo play a part in the path? The conditions looked pretty poor as can be seen from the image below.

It seems unlikely that any sort of tropo ducting played any part in this reception report.

Theory 3... Refection from the International Space Station??? It would seem as if the International Space Station (ISS) was above the horizon at the same time.

In response to my original theory that it was double hop meteor scatter, Alejandro LU8YD from Argentina writes... 

"My opinion is that the QSO analysis is not correct. You have to check the location of the ISS space station at the time of the QSO and you will see that it was crossing the path between stations LZ and OY. In my opinion it is a QSO by Spacecraft scatter and not by meteor scatter. Reflections of amateur radio signals by the ISS as a passive reflector has occurred before. Despite this, it must be considered an extraordinary QSO and achievement by LZ1KU and OY9JD for which I congratulate them.

Please send my regards and congratulations to Stamen and Jon

Kind regards Alejandro LU8YD"

After receiving Alejandro's message, I checked out the position of the ISS on the morning of the 14th of December.

The beam heading from the Faroe Islands to Bulgaria is 147 degrees. The time stamp on the MSK144 signal was 11:03 UTC.

It's not a perfect match but the ISS was certainly in the same general area of sky at the time. The ISS reached a maximum elevation of 10 degrees during that pass and it was probably around 4-5 degrees at 11:03 UTC.

This is the view of the pass from Bulgaria...

From the Bulgarian perspective with a higher pass, the time and beam heading seem closer aligned. The Faroe Islands are on a beam heading of 327 degrees from Bulgaria.

Considering the size of the ISS and the size of the reflective surface, it has to considered a strong contender for the reception report.

However, I still have some questions. What about doppler shift? Would the doppler shift have moved the signals outside the receive passband of the receiver? What impact does doppler have on a MSK144 signal and the ability to decode it?

Conclusion (Updated)... My original thinking was that it was probably double hop meteor scatter. After all, there must be occasions when two meteors trails just happen to line up in the correct position at the same time.

The fact that the International Space Station was in the same area of sky at the same time must make this the most likely reason although in retrospect, I don't think we can be absolutely certain but it does seem likely.

I'd be inclined to say 90:10 in favour of refection off the ISS as opposed to double hop MS but others may have different opinions.

North Atlantic on 144 MHz??? ... Here is an intriguing thought: If the signal at 144 MHz can get 3075 kms from the Faroe Islands to Bulgaria was via double hop meteor scatter then why not across the North Atlantic from Ireland/UK to Newfoundland?

New World Meteor Scatter Record on 144 MHz... 7th Aug 2018

It seems to be a week of new records on 144 MHz. Following on from the new Region 1 tropo record on the 5th of August 2018, a new world record for meteor scatter on 144 MHz was set on the 7th of August.

In the early hours of the 7th of August, Dieter DJ6AG (JO51eq) in Germany worked Fernando EA8TX (IL18qi) in the Canary Islands to set a new world distance record of 3428 kms. The FSK contact took several hours to complete with the final decode being received in Germany at 00:14 UTC.

001430 16.0 220 1 26 9 R!RRRR EA TX RRRR RRRR EA8TX RRRR

The new record of 3428 kms breaks the old record between EA8TJ and S50C by 51 kms.

Previous best distances by meteor scatter on 144 MHz in Region 1...

Distance record on 144 MHz Propagation : MS
Band Propagation Call a Loc Call b Loc Mode Date Distance
144 MHz MS S50C JN76JG EA8TJ IL18RJ FSK441 2013-08-12 3377
144 MHz MS EA8TJ IL18RJ PA4EME JO20WX FSK441 2013-08-12 3132
144 MHz MS GW4CQT IO81LP UW6MA KN97VE CW 1977-08-12 3101
144 MHz MS HB9FAP JN47PH EA8TX IL18QI FSK441 2014-08-14 3077
144 MHz MS HB9FAP JN47PH EA8TJ IL18RJ FSK441 2013-08-13 3069

It's very probable that there was a combination of meteor scatter and tropo involved in this record. It was probably a long meteor scatter hop of about 2,200-2,300 kms from Germany to the south coast of Portugal and marine ducting tropo from there to the Canary Islands.

Is this the maximum?

GB3RAL on 28 MHz via Meteor Scatter

On Friday the 18th of November, I had the rig turned to 28.2150 MHz, the frequency of the GB3RAL 10 metre beacon in the UK.

I was using Spectrum Lab on the PC with the microphone resting on top of the HF rig....an easy way to monitor a frequency while working away on something else. If there is anything there buried in the noise, it will usually show up on the screen.

I've listened to this back in 2008 and found it hard to get a positive ID. It seemed to be just a carrier without any CW.

This time around, I got 'AL' on cw within about 20 minutes so I knew I was hearing it. There were plenty of pings over the space of an hour and then at about 10:28 UTC, I got this fine 4 minute burst...

Right hand side shows the audio freq in Hz.

The tone was easy to hear at times as it transmitted "GB3RAL IO91IN". It certainly wasn't a huge signal...maybe 419 at best but clear all the same.

I'd imagine it would have been really easy to make a contact on a digital mode like JT65.

It was only afterwards that I noticed that the Leonid meteor shower peaks on the 18th of November so perhaps it was due to one of those.

On a positive note, it's good that the new 10 metre vertical seems to be working well.

GB3RAL on 28 MHz & the Ursids Meteor Shower

On the morning of the 22nd of Dec 2008, I had a listen for meteor bursts from the GB3RAL beacon on 28.215 MHz during the Ursids meteor shower. This shower is supposed to have a number of active 'outburts' sometimes. This year, the forecast for the peak was for 07:30 UTC.

Why GB3RAL??.........I tried listening to other beacons in Europe around the 1,200 km to 1,500 km mark. Some run very low power so the refections are very weak. In addition, this distance is very good when there is any type of Sporadic-E propogation and it can be very hard at times to tell the difference between the Sp-E and meteor scatter. At least with GB3RAL at 490 kms, Sporadic-E is somewhat less likely and reflections for meteor scatter are likely to be stronger although shorter in lenght.

Equipment : As before, Kenwood transceiver on CW with a 500 Hz filter. Antenna in use was an old CB type half wave vertical.

Listening Period.........07:00 to 10:00 UTC on the 22nd of December 2008.

Results.......Plenty of pings and bursts but there was nothing spectacular. I didn't notice any particular sharp peak in activity. At best, it could be described as 'a small' increase in what be heard normally.

For the 3 hours, the level seemed to be much the same.

Between 08:00 and 09:00 UTC, I heard 9 pings and 9 bursts (10 sec x 1, 20 sec x 3, 30 sec x 3, 60 sec x 2).

Between 09:00 and 10:00 UTC, I heard 14 pings and 9 bursts (10 sec x 3, 20 sec x 3, 30 sec x 1, 60 sec x 2).

All signals were pretty weak. Note however that it was not possible to get a positive ID of the GB3RAL beacon as it's keyer is currently faulty. However, there would seem to be nothing else that it could be other than GB3RAL as there is no other beacon listed within meteor scatter range on that frequency.

From my point of view, there did not seem to be any 'outburst' in activity. Looking at the activity level plotted on the Make More Miles on VHF website, it does not seem to show much activity either. On the chart, the Geminids show up very clearly whereas the Ursids look pretty poor.

It looks as if the 2008 Ursid meteor shower was nothing special.

The next shower is the Quadrantids. These are supposed to peak at 13:00 UTC on the 3rd of Jan 2009.

Beacons on 28 MHz during the Geminids meteor shower...14th Dec 2008

Back in mid November, I tried a few tests listening to the beacon GB3RAL on 28 MHz during the Leonids meteor shower. For the Geminids, I repeated some of the tests but this time, tried listening for some other beacons as well.


Equipment...
Same as the last time....Kenwood transciever on CW, 500 Hz filter. Antenna....old commercial CB type end fed half wave about 4 metres above ground level. I monitored the received audio using the Sprectrum Lab audio analyzer program.

I tried listening for 4 different beacons on 28 MHz......GB3RAL (~500 kms), LA4TEN (~1,200 kms), F5ZWE (~1,300 kms) and DL0IGI (~1,500 kms). I listened at two different times on the 14th of December.....around 01:00 for GB3RAL and LA4TEN and around 09:00 for all 4 beacons.


Listening around 01:00......
GB3RAL.....I received a few bursts from this beacon. Nothing spectacular but it seemed to be there ok. Due to the fact that it has a faulty keyer, I was not able to get a positive ID. Like before, a lot more shows up on the trace than what I could hear by ear.


LA4TEN......This beacon seemed to be very good. It seemed to be nearly always there and at times, it got strong enough so that I could hear the CW by ear and make a positive ID.


Why was the LA4TEN beacon so consistent?

1) My view in that direction is excellent with no obstructions so that may have helped.
2) Is it the fact that 1,200 kms might be a much better distance for meteor scatter. Certainly for GB3RAL at 500 kms, I would expect that more intense meteor bursts might be required (more ionization) and the bursts would be of shorter duration.
3) Perhaps certain directions are better at different times during the shower??
4) Or perhaps it was the power level? LA4TEN is supposed to have an ERP of 250 watts which is very high for a beacon.
5) Of course, there is always the chance that what I heard was actually weak Sporadic-E rather than just meteor scatter propogation. It's seems unlikely at 1am in the morning in December. Considering that the peak of the shower was around this time, it was probably meteor scatter.

Listening around 09:00....
Conditions were worse. I still got a few pings from GB3RAL. I got very little from DL0IGI and F5ZWE. However, LA4TEN seemed as busy as ever! Looking at other sites, the peak was well over at this stage. In addition, the radiant point for the showers in Gemini may have set below the horizon by that time. I wonder though if the LA4 beacon at this stage was Sporadic-E or or not???



Conclusions.......
1) I need to find out what times the radiant point is above the horizon for any future shower and what the likely peak time will be.
2) The results show that meteor scater on 28 MHz is pretty impressive. Everything heard here was with an antenna with no gain.


Useful links......
International Meteor Organisation
G7IZU meteor detection page

Next shower is the Ursids on the 22nd of December.

GB3RAL and the Leonids Meteor Shower...17th Nov 2008

This is a post that I have been meaning to put up for a while. Now that the peak of the Geminids meteor shower is coming up next weekend (13th of Dec), now seems like a good time to put it up.

During the morning of the 17th of November which was supposed to be the peak of the Leonids meteor shower, I tried listening for the GB3RAL beacon in England on 28.215 MHz.

Equipment.....Kenwood TS690s tuned to 28.215.1 MHz on CW (500 Hz filter fitted)
Antenna........Half wave 10 metre vertical at 5 metres AGL
Distance......490 kms due East from here (IO91in<->IO51tu)

As well as listening by ear to the received signals, I put the microphone from the PC next to the rig and monitored the signal with the Spectrum Lab Audio Analyzer program.

After a while, I got a few audible pings that showed on the waterfall dislay so I could see that there was something there around 500 Hz.



At 09:24, I recorded what was the start of a long 5 to 6 minute burst. As you can see above, it started suddenly and after a few minutes, it began to slowly fade away. Listening by ear, I could just about hear that there was something there yet it showed up quite clearly on the waterfall display.

From what I could hear, there was no cw. It was just a constant carrier.


However when I looked at the display closer, I could see that the signal was about 7 Hz wide before finally becoming a narrower signal. I can see from beacon lists that the GB3RAL beacon uses FSK....i.e. the carrier moves in frequency to generate the CW rather than turning on and off. I asked the beacon keeper G0MJW about this and he informed me that the keyer on the beacon has failed and a replacement is under construction.

What I heard and saw was like the beacon keyer was still working (i.e. FSK) except that the frequency shift was now a lot lower than it should be (i.e. 7 Hz instead of say 300 Hz).

Q. Was it GB3RAL that I heard? Probably likely but to be honest, until I can get a positive ID, I will never be 100% sure. I might have a listen again during the Geminids and see how it goes.

Notes...
(1) The various other lines shown on the above displays are mainly just interference generated by the PC. Even though I can't hear them, they show up quite clearly on the display.