Backscatter on 28 MHz - 2nd Nov 2023

For well over 12-months, I have had my radio tuned to the WSPR frequency of 28.1246 MHz on the 10m band and I feed the decoded signals up to the WSPRnet website.

While I can see the WSPR signals clearly on the waterfall display, I can also see the very slow morse QRSS signals as well just a few hundred Hz below.

The image above shows the QRSS signals I could see on the 2nd of November 2023 and the locations of the stations are shown in the map at the start of the post.

The screenshot above shows a good capture of AE0V in the USA at about a distance of 6000kms. Ned, AE0V reports using a solar powered transmitter with no battery storage running 100mW into a 1/4 lamba stainless whip about 8m above the ground.

The signals from the USA and Canada are easily explained as they are via F2 layer propagation. The signals I find unusual are the ones from the England which are in the region of 500 to 650kms.

The trace from the 0.2-watt signals of G0PKT and G0MBA are there nearly all the time when the band is open. It's not F2 propagation in the usual sense as it's too close and it's not Sporadic-E.

I believe that it's backscatter just like what the military use for their over the horizon radar systems (OTHR). 

In this case, the 28 MHz band is open with F2 layer propagation and the signals from G0PKT & G0MBA are being reflected back towards my location from some distant point.

As an example of how consistent these signals are, I have decoded the WSPR signal of G0PKT about 1,000 times in the last 3-weeks. And that's a signal that's supposed to be in my 'skip zone' where it's supposed to be hard to reach.

There's nothing new about this, it's just that in this modern age of weak signal modes and waterfall displays, we can now see these very weak signals more clearly. 

If you're using FT8 on the higher HF bands and you see lots of reports from stations that about 200-600kms away then F2 backscatter is probably the reason.

Winter 2022 release of the QRSS Compendium 5th Edition

Every year, the Knights QRSS Group release their annual compendium. You can view the Winter 2022 (5th edition) HERE

The Knights QRSS Group promotes the use of very slow mode code beacons to carry out propagation experiments on the HF bands. Often signals that are 15 to 20 dB below the noise can be seen on a computer screen as opposed to being heard by ear.

While newer digital modes can now be used for detecting very weak signals, they don't really show propagation effects. Either the digital signal was decoded or it wasn't. QRSS signals like the one shown below shows propagation over a 15-minute period.

In that image, you can see how signals fade with the Sporadic-E footprint moving and the polarisation changing. It also shows up slight doppler effects.

You can find out more about QRSS signals by visiting the QRSS Knights Groups.io page... https://groups.io/g/qrssknights/topics

Mid-Winter Sporadic-E opening on 28 MHz - Mon 19th Dec 2022

Normally the main Sporadic-E season normally lasts from May to August every year but there is also a smaller secondary peak during the Winter months. While I was listening for WSPR signals on 28 MHz yesterday, I noticed that there was a Sporadic-E opening on the band.

While this isn't that unusual, what caught my attention was the fact that the skip distance was short for 10m and I was hearing stations in England. The map above shows some of the European stations that I heard on WSPR including a batch in England.

Most of these English stations were in the region of 500-700kms which is reasonably short and unusual. It's much easier for me to hear say German stations during a Sporadic-E opening as they are around the 1200-1500km mark.

What alerted me to the short skip was the sound of the QRSS signals from England coming through on the WSPR frequency of 28.1246 MHz.

QRSS is a very slow form of morse code where a single callsign is sent over a period of a few minutes and the call can be decoded by looking at the audio spectrum on a screen. Signals that are up to 20dB below the noise level can be seen and in a way, this was the original 'buried in the noise' signal mode before the likes of FT8 and WSPR arrived on the scene.

In the example above, the 10m QRSS signals are about 500Hz below the WSPR signals and in the same audio passband.

It's likely there will be more Sporadic-E openings on 28 MHz and 50 MHz over the Christmas period, have a listen.

QRSS signals heard on 28 MHz - 1st Nov 2022

Every day, I leave my HF radio on the 28.1246 MHz to listen for WSPR signals. My PC then decodes these and sends the reception reports up to WSPRNet website for others to see.

The QRSS (very slow morse code) band is just a few hundred Hz below the 10m WSPR band and I noticed in the WSPR waterfall that two QRSS signals were present so I had a look.

The image above shows the QRSS signals that I was hearing over a period of about 20-25 minutes on the 1st of November 2022.

VE1VDM in Canada and G0PKT in the east of England had reasonable signals and they were the two I had noticed initially. G6GN in England is also present but quite weak. There are other very weak QRSS signals as well but I was unable to ID these.

The locations of the relevant stations are shown on the map below.

VE1VDM in Nova Scotia is 4000kms from my location and is easily explained as it's an ideal one F2 layer hop away on 28 MHz.

The signals from G6GN at 400kms and G0PKT at 650 kms are not so easily explained. If it was the Summer months then we might think it was Sporadic-E but, this was the first of November AND G0PKT is pretty much there all of the time every day when the band is open.

I suspect that I am receiving these signals via F2 layer backscatter. In the past (pre digital days), backscatter signals were pretty much buried in the noise with the SSB and CW modes. Now however, WSPR has no problem decoding signals that are 20dB below the noise level and I can see QRSS signals which are in the region of -15 to -20dB.

I think a lot of those 'close in' signals that we are now seeing on WSPR or FT8 on 28 MHz are in reality via backscatter.

You can see from the map above all of the WSPR stations I heard on 28 MHz on the 1st of November. Meteor Scatter? Forward scatter via Sporadic-E? I'm opting for F2 layer backscatter.

I'm using an omni-directional vertical on 28 MHz so I can't beam headings. Maybe someone else wants to do some tests? See which direction those 'close in' signals are strongest. The direct path OR beaming in some other direction at a potential back-scatter point?

New 40 MHz beacon in Washington State - Feb 2022

Halden Field, NR7V is one of the few US radio amateurs who managed to get a special experimental permit to operate on the 40 MHz band and was allocated the callsign WM2XCW back in the second half of 2021.

He has now announced that he has an experimental CW beacon is on the air on the 40 MHz band.

He writes..."The purposes of this beacon are:
1.  To enable detection of propagation openings on this band that would not be detected by reception of WSPR transmissions.
2.  To enable analytical measurements of such detected propagation, including
 a.  signal strength and its variations
 b.  wavelength shift and broadening during propagation"

This beacon transmits on 40.6630 MHz which is about 400 Hz below the 200Hz of spectrum used at present for WSPR transmissions.

This will allow people to listen both for the new beacon and to WSPR transmissions at the same time. The same method is used for QRSS transmissions on the HF bands and is very effective.

The beacon will transmit once every 10 minutes, following its WSPR transmissions.  It sends identifying information in 18 wpm Morse code and then a carrier for 30 seconds.  The beacon location is at Point Roberts in the far north-west of Washington State and the locator square is CN88. 

The beacon uses a QRP-Labs U3S with a 10W Linear PA and the antenna is a dipole about 9m above ground level. It is orientated to favour transmission to the NW and SE.

The map above shows the location of the beacon in the NW of the United States. The lobes of the antenna are also shown going NW & SE.

Most of the reception reports are likely to come from the western half of the USA and in the region of 1000-2100 kms and the propagation mode will be Sporadic-E. At the peak of the Sp-E season in late May and all of June, there will be double hop Sp-E openings to the eastern part of the USA in the range of 2600-3500kms.

It will be very difficult to hear the beacon in Europe as it's a northerly path and it's in the null of the dipole.

There is the possibility of some very interesting openings to Japan with multi-hop Sp-E or via Sp-E & TEP to South America. The biggest challenge here is getting someone interested enough to try and listen.

As we head towards the peak of the solar cycle, some F2 openings are likely on the 40 MHz band and it will be interesting to see if the beacon is heard on the east coast of the United States.

Any reception reports should be sent to NR7V or on the DX-Maps website.

Link...
1) For more info on the 8m band, check out my 40 MHz page.

Winter 2021 release of the QRSS Compendium 4th Edition

Every year, the Knights QRSS Group release their annual compendium. You can view the Winter 2021 (4th edition) HERE

The Knights QRSS Group promotes the use of very slow mode code beacons to carry out propagation experiments on the HF bands. Often signals that are 15 to 20 dB below the noise can be seen on a computer screen as opposed to being heard by ear.

While newer digital modes can now be used for detecting very weak signals, they don't really show propagation effects. Either the digital signal was decoded or it wasn't. QRSS signals like the one shown below shows propagation over a 15-minute period.

In that image, you can see how signals fade with the Sporadic-E footprint moving and the polarisation changing. It also shows up slight doppler effects.

You can find out more about QRSS signals by visiting the QRSS Knights Groups.io page... https://groups.io/g/qrssknights/topics

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.

IW0HK QRSS beacon heard on 28 MHz - 12th Nov 2021

Friday 12th November 2021: Normally it's during the Summer months and the main Sporadic-E season that I have a look for QRSS signals on the 28 MHz band (QRSS - Very slow visual form of morse code).

During a short Sporadic-E opening on 28 MHz the 12th of November, I noticed that I was hearing the IW0HK beacon near Rome on 28.3219 MHz. I didn't recognise the callsign and I had to check the cluster to see that I last heard it back on the 25th of May 2019.

I noticed on the beacon list that it was also a QRSS beacon so I fired up Spectrum Lab and grabbed the screen shot above.

As you can see, the QRSS ID is 'H K' which is sent over the space of about 1-minute.

The power is listed as 1-watt and the antenna is a vertical.

The distance as seen from the map below is about 1900kms which is pretty normal for Sporadic-E. It's just a little unusual to get it at nearly 9pm local time in November.

Trans-Atlantic opening on 28 MHz (QRSS signals from VE1VDM & N8NJ) - 19th June 2021

19th June 2021: After getting an email from Vernon VE1VDM, I fired up the Spectrum Lab programme and managed to grab TWO trans-Atlantic QRSS signals on 28 MHz...

(QRSS are morse code signals sent very slowly over a period of several minutes. This is an analogue method of reading signals that are buried in the noise)

It was probably the strongest capture I've got to date of VE1VDM and the first time I've managed to capture N8NJ. His power was 2-watts.

N8NJ is also the longest distance QRSS signal on 28 MHz I've captured as well. His power was 1-watt.

These are the WSPR reports around that time so you can compare what the QRSS signal looks like against the WSPR signal report.

2021-06-19 13:20 VE1VDM FN85ij EI7GL IO51tu 28.126151 2 -15 0 4001
2021-06-19 13:20 N8NJ EN81go EI7GL IO51tu 28.126069 1 -20 0 5574
2021-06-19 13:30 VE1VDM FN85ij EI7GL IO51tu 28.126151 2 -13 0 4001
2021-06-19 13:30 N8NJ EN81go EI7GL IO51tu 28.12607 1 -24 0 5574
2021-06-19 13:40 VE1VDM FN85ij EI7GL IO51tu 28.126151 2 -15 0 4001

VE1VDM at -13 to -15dB was at a level which would be barely detectable by ear. It's too weak for CW sent at normal speed.

N8NJ at -20 to -24dB was buried well into the noise.

In truth, there's nothing that remarkable about hearing Canada or the USA on 28 MHz during the peak of the Summer Sporadic-E season but it was still nice to get a screen capture of two low power stations from the other side of the Atlantic.

WSPR North-South Divide on 28 MHz - 16th May 2021

Sunday 16th May 2021: This was similar to the previous few days with plenty of Sporadic-E on 28 MHz but it was less intense. I heard 465 WSPR transmissions from 71 different station on the band.

The unusual signals on this day was the appearance of TA4/G8SCU in Turkey and TF3HZ in Iceland. 

There was some short skip to the UK as well with 15 stations heard but it didn't seem as good as previous days.

I was also reminded about one of the main issues with WSPR on 28 MHz i.e. the lack of stations in some countries.

North-South Divide: As you can see from the map above, there is a real lack of signals from the south of Europe. For example, there are hardly any WSPR signals coming from Portugal, Spain, France and Italy.

When I was monitoring the 10m WSPR band on Sunday evening, I hadn't decoded anything in over an hour. I thought the band was closed. I then switched over to FT8 and there were plenty of stations coming through from Spain, Italy and Brazil.

It really is hard to beat FT8 in terms of getting an overall idea of where the band is open to.

QRSS (Very Slow Morse): With the skip going long, I managed to get a screen grab of the QRSS signals from TF3HZ in Iceland.

28MHz band stays open all day - Thurs 13th May 2021

After the aurora and disturbed conditions on Wednesday the 12th of May, the 28 MHz band opened on that evening at about 18:00 UTC. What was really unusual was that the band stayed open that night and all through Thursday the 13th of May... roughly 36 hours. This is in marked contrast to the Sporadic-E openings for the previous few weeks where the band might open at some stage during the day and then close late in the evening.

As the 28 MHz band was open all day, I left the radio monitoring the WSPR frequency for the 24 hours. I heard a total of 945 WSPR transmissions from 87 stations around Europe which is very encouraging as it looked a few week back that there was very little WSPR activity.

The map above shows what I heard. What makes it different from FT8 is that there is a wide distribution of FT8 stations spread across Europe that are trying to make contacts. WSPR however is concentrated in pockets of activity based around mainly the west of Germany, the Netherlands and the south of England.

What I found of interest was the short skip opening to the UK...

Distances of about 1000 to 2200 kms are pretty common on 28 MHz during Sporadic-E openings but the opening needs to be really intense for the skip distance to drop down to 500kms or less.

UTC (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km
2021-05-13 04:58 EI2SBC IO63dj EI7GL IO51tu 28.126074 5 -27 -3 177
2021-05-13 09:38 MW0GRJ IO83kf EI7GL IO51tu 28.126038 5 -27 4 386
2021-05-13 10:10 G4SRD IO81wi EI7GL IO51tu 28.126088 10 -17 -1 435
2021-05-13 09:38 G4SDL IO83tk EI7GL IO51tu 28.126101 1 -21 1 441
2021-05-13 07:14 G4HZW IO83uh EI7GL IO51tu 28.12613 5 -20 1 442
2021-05-13 10:04 G7GXK IO90is EI7GL IO51tu 28.126099 0.2 -27 0 507
2021-05-13 10:38 2M0WHX IO75wv EI7GL IO51tu 28.126035 5 -16 0 529
2021-05-13 06:20 M0SDM IO92pv EI7GL IO51tu 28.126006 2 -26 1 533
2021-05-13 06:36 G8IOA IO92rp EI7GL IO51tu 28.126092 5 -16 -1 540
2021-05-13 06:30 M0NMA IO92sp EI7GL IO51tu 28.126077 5 -11 -1 546
2021-05-13 06:08 M0GBZ IO91vv EI7GL IO51tu 28.126143 0.5 -19 0 560
2021-05-13 09:44 G6JVT IO90st EI7GL IO51tu 28.126111 0.2 -26 -1 562
2021-05-13 10:16 G4NXH IO94hu EI7GL IO51tu 28.126101 0.1 -26 0 572
2021-05-13 06:40 G4KPX JO02dj EI7GL IO51tu 28.12607 0.005 -23 0 594
2021-05-13 06:18 M0XDC JO01dq EI7GL IO51tu 28.12607 5 -22 0 596

2021-05-13 12:28 G4EDR IO94uf EI7GL IO51tu 28.126091 5 1 2 601
2021-05-13 10:08 G3JKF JO00bs EI7GL IO51tu 28.126125 5 -27 0 603
2021-05-13 10:42 G3DVF IO95 EI7GL IO51tu 28.126179 0.2 -26 0 629
2021-05-13 08:10 G4NJJ JO02 EI7GL IO51tu 28.126076 0.2 -21 -3 640
2021-05-13 05:58 G0MBA JO01 EI7GL IO51tu 28.126046 0.2 7 0 645
2021-05-13 05:58 G0PKT JO01mt EI7GL IO51tu 28.126056 0.2 0 0 647
2021-05-13 06:38 G0FTD JO01mi EI7GL IO51tu 28.126112 0.2 -24 0 652
2021-05-13 09:34 GM1OXB IO87lp EI7GL IO51tu 28.126049 2 -6 0 729

The most unusual signal was that of EI2SBC (Shannon Basin Radio Club) which was 177kms to the north of me. I heard two WSPR transmissions...

UTC (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km
2021-05-13 04:58 EI2SBC IO63dj EI7GL IO51tu 28.126074 5 -27 -3 177
2021-05-13 14:58 EI2SBC IO63dj EI7GL IO51tu 28.126078 5 -26 -3 177

Propagation mode? At 177kms, tropo is a possibility even on 28 MHz but I don't think it was. I suspect is was either very short Sporadic-E or Sporadic-E back-scatter. They were running 5 watts which is reasonably high power level for WSPR so it's difficult to be sure.

QRSS: One of the advantages of listening to WSPR is that I can see any QRSS (very slow morse) signals as well as those signals are just below the WSPR ones.

The image above shows a screen grab I took early on Thursday morning. Most of those stations in the Uk were east of London and about 650kms from me.

As an example, the signal say from G0FTD in this image is probably weaker than -20dB and in reality is buried in the noise.

Opening on 28 MHz after Aurora - Wed 12th May 2021

Wednesday the 12th of May 2021 was an unusual day. The first half of the day seemed to be dead on 28 MHz with very little happening which was probably due to an aurora in progress. From about 18:00 UTC onwards, it sprung into life. This is what I heard on FT8 up until 18:30 UTC...

Once it was obvious that the signals were getting stronger, I moved over to monitoring for WSPR signals...

A total of 20 stations were spotted from the northern part of Europe. What was unusual was that the band just seemed to stay open up till midnight and then stayed open overnight.

What was also unusual for me was that I was hearing the SE of the UK which is about 650kms away for several hours. These are some weak QRSS signals I got a grab of...

What was unusual was just steady the signals were. Normally with short skip on 28 MHz, the signals are fading. QRSS signals come in and fade away. On the 12th, the QRSS signals from the UK just seemed to be there at a pretty consistent level for hours. They never got that strong as can be seen from the WSPR reports below but the QRSS signals never really faded out either.

UTC (y-m-d) TX txGrid RX rxGrid MHz W SNR    drift km
2021-05-12 20:48 G0MBA JO01 EI7GL IO51tu 28.126053 0.2 -25 0 645
2021-05-12 18:48 G0PKT JO01mt EI7GL IO51tu 28.126062 0.2 -23 0 647
2021-05-12 19:48 G0PKT JO01mt EI7GL IO51tu 28.126062 0.2 -28 0 647
2021-05-12 20:48 G0PKT JO01mt EI7GL IO51tu 28.126064 0.2 -21 0 647
2021-05-12 20:58 G0PKT JO01mt EI7GL IO51tu 28.126063 0.2 -23 0 647

This was the day of the season where the band seems to stayed open to Europe overnight.

A connection with the aurora event or just coincidence?

28 MHz Report for Sun 9th May 2021

Sunday 9th May 2021: While the 9th didn't seem to be as good as the 7th & 8th, there were still lots of Sporadic-E signals on 28 MHz for most of the day. Again, I spent most of the day on WSPR with the receive map for me shown above.

This time, I heard 7 stations running 50mW or less.

(y-m-d) TX txGrid RX rxGrid MHz W SNR drift km
2021-05-09 10:56 G4KPX JO02dj EI7GL IO51tu 28.126063 0.005 -6 
2021-05-09 09:06 DJ4RH JN49bx EI7GL IO51tu 28.126088 0.01 -23 
2021-05-09 10:06 PD0KT JO33le EI7GL IO51tu 28.126094 0.01 -23 
2021-05-09 09:56 OZ0RF JO65fr EI7GL IO51tu 28.125994 0.02 -23 
2021-05-09 08:36 DL1WER JN58cd EI7GL IO51tu 28.126116 0.05 -18 
2021-05-09 08:54 DK9ES JO31 EI7GL IO51tu 28.12608 0.05 -24 
2021-05-09 18:04 ON4LUK JO11  EI7GL IO51tu 28.126197 0.05 -23 

When the skip went short, I managed to get two QRSS (very slow morse) plots from two stations east of London, about 600kms from me.

I also spent some time monitoring the FT8 frequency and I heard 279 stations in 36 countries.

28 MHz report for Sat 8th May 2021

 

Saturday 8th May 2021: This was another day where the 28 MHz band seemed to be wide open with lots of Sporadic-E signals from Europe. I heard 358 stations on FT8 in 29 countries but that was only listening on the FT8 frequency for a few hours.

I spent most of the day monitoring the WSPR frequency instead and the chart of stations heard is shown above. As can be seen from the chart, I heard 3 stations running less then 100-milliwatts.

Beacons: These were the beacons heard.

EI7GL 28207.1 ON0RY/B 19:37 08 May IO51TU<ES>JO20CK Belgium

EI7GL 28243.0 F5ZWE/B 14:03 08 May IO51TU<ES>JN02TW France

EI7GL 28194.0 IW4EIR/B 13:04 08 May IO51TU<ES>JN54AS Italy

EI7GL 28240.0 IZ8RVA/B 13:01 08 May IO51TU<ES>JN70LI Italy

EI7GL 28227.2 IW3FZQ/B 13:00 08 May IO51TU<ES>JN55VF Italy

EI7GL 28173.1 IZ1EPM/B 12:57 08 May IO51TU<ES>JN35WD Italy

EI7GL 28257.8 DK0TEN/B 11:02 08 May IO51TU<ES>JN47NT Fed. Rep. of Germany

EI7GL 28205.0 DL0IGI/B 10:23 08 May IO51TU<ES>JN57MT Fed. Rep. of Germany

EI7GL 28241.6 F5ZUU/B 08:12 08 May IO51TU<ES>JN24IL France

QRSS: The best thing about listening to WSPR is that I can monitor for QRSS signals as well as they just 500 Hz or so below the WSPR frequency. I managed to get one screen grab of ON4CDJ in Belgium.

The Sporadic-E season has well and truly started at this stage and you can expect to see lot of signals on the 10m band from now until late July.

Short skip opening on 28 MHz - 23rd Jan 2021

Over last week, there have been plenty of days where the 10m has been practically dead all day. So it came as a bit of a surprise when there was a nice short opening on Saturday the 23rd of January 2021.

The main opening was when there was some Sporadic-E in the evening time. What was unusual was the fact that there was short skip from here to the east of the UK, a distance of about 500-600kms.

I had a listen for some QRSS signals when the skip went short and I got this screen grab...

Despite the fact that we are now 13 months in the new sunspot cycle, the solar flux was only 78 today. Was the surge in sunspots last November just a false dawn?

I suspect conditions on north-south paths on 10m should pick up in March and after that, we're into the start of the Sporadic-E season in late April.

Winter 2020 release of the QRSS Compendium 3rd Edition

Every year, the Knights QRSS Group release their annual compendium. You can view the Winter 2020 (3rd edition) HERE

The Knights QRSS Group promotes the use of very slow mode code beacons to carry out propagation experiments on the HF bands. Often signals that are 15 to 20 dB below the noise can be seen on a computer screen as opposed to being heard by ear.

While newer digital modes can now be used for detecting very weak signals, they don't really show propagation effects. Either the digital signal was decoded or it wasn't. QRSS signals like the one shown below shows propagation over a 15-minute period.

In that image, you can see how signals fade with the Sporadic-E footprint moving and the polarisation changing. It also shows up slight doppler effects.

You can find out more about QRSS signals by visiting the QRSS Knights Groups.io page... https://groups.io/g/qrssknights/topics

WSPR balloon on 20m over the Arctic - 10th June 2020

On the morning of the 10th of June, I left the radio monitoring the WSPR frequency on 20m to see if I would hear anything special. I noted two signals...

Australia... The first was the signal from VK3MO and VK3QN in Australia, always interesting because of the distance. I'm not 100% sure though if they were short path as shown on the map or long path. Might be something worth checking another time.

The one that really caught my eye was the VE3KCL callsign with the strange locator. I assumed at first a decoding error but no, it turns out to be a very small WSPR transmitter hung underneath a helium balloon over the Arctic Ocean!

As of the evening of the 10th of June, it was at an altitude of 10,000 metres, in constant sunlight, has a temperature of minus 6 deg C and is travelling at 18 knots.

It sends out a WSPR signals on 20m with a power output of 10 milliwatts. It was launched on the 16th of May 2020 and has is now starting its third circumnavigation of the planet.

More info here... http://qrp-labs.com/flights/u4b9.html

There are some of the WSPR decodes that I got which shows the locator square changing...

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2020-06-10 20:58  VE3KCL  14.097177  -30  0 MR20 0.01 EI7GL IO51tu  4047 266 
 2020-06-10 20:38  VE3KCL  14.097178  -29  0 MR10 0.01 EI7GL IO51tu  4011 264 
 2020-06-10 19:48  VE3KCL  14.097178  -25  0 MR11 0.01 EI7GL IO51tu  4024 262 
 2020-06-10 18:38  VE3KCL  14.097184  -25  0 MR01 0.01 EI7GL IO51tu  3992 260

In addition to the QSPR signal, it is also sending out a QRSS signal in the form of a balloon!

The image I got a grab of isn't great but you can make out the circle in the waterfall.

Trans-Atlantic opening on 28 MHz - Sun 7th June 2020

There was a nice trans-Atlantic opening on 28 MHz and 50 MHz late on Sunday the 7th of June 2020. I had no real interest in trying to make any contacts so I left the radio monitoring the WSPR frequency on 28.1246 MHz.

WSPR signals heard...

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km
 2020-06-07 23:40 W8AC 28.126032  -24  0 EN91jm  5  EI7GL IO51tu  5434
 2020-06-07 23:28 W8AC 28.126032  -26  0  EN91jm  5  EI7GL IO51tu  5434
 2020-06-07 23:24 W8EDU  28.126102  -26  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 23:12 W8EDU  28.126102  -23  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 23:10 W8AC 28.126032  -25  0  EN91jm  5  EI7GL IO51tu  5434
 2020-06-07 23:04 W8EDU  28.126102  -26  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 22:58 WA9WTK  28.126062 -23  0  FN42fk  10  EI7GL  IO51tu  4734
 2020-06-07 22:58 WB8ILI  28.126083 -25  -1 EN82pq  5 EI7GL IO51tu  5451
 2020-06-07 22:56 W8EDU  28.126102  -22  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 22:18 WA3DNM  28.126074 -18  0  FM29fw  5  EI7GL  IO51tu  5168
 2020-06-07 22:10 VE1VDM  28.126125 -26  0  FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 22:00 VE1VDM  28.126125 -23  0  FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 21:58 WA9WTK  28.126063 -22  0  FN42fk  10  EI7GL  IO51tu  4734
 2020-06-07 21:50 VE1VDM  28.126125 -21  -1 FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 21:40 WA3DNM  28.126075 -17  0  FM29fw  5  EI7GL  IO51tu  5168
 2020-06-07 21:40 VE1VDM  28.126124 -23  0  FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 21:38 WA3DNM  28.126075 -15  0  FM29fw  5  EI7GL  IO51tu  5168
 2020-06-07 21:30 VE1VDM  28.126124 -22  -1 FN85ij  2 EI7GL IO51tu  4001

VE1VDM was the first signal heard at 21:30 UTC and the last trans-Atlantic signal was from W8AC in Ohio at 23:40 UTC.

Most of the stations were running 4, 5 or 10 watts. The strongest SNR (Signal to Noise ratio) was -15dB which would have meant that it was buried in the noise and barely perceptible by ear.

I suspect the signals from VE1VDM may have been double hop Sporadic-E while the US stations were triple hop.

QRSS... Most the QRSS (very slow morse) transmissions from North America are just below the WSPR frequency. This allow you to look at the WSPR waterfall display in WSJT-X and see if there are any QRSS signals there.

As soon as I heard VE1VDM in Nova Scotia on WSPR, I opened up the SpectrumLab programme to take this screen grab...

In the graphic above, the vertical dotted lines mark 5 minutes of time so the scan from left to right took about 20 minutes. You wouldn't want to be in a rush to go anywhere with QRSS 😊

The signal from VE1VDM was actually stronger before this grab was taken so I would guess the QRSS signal is equivalent to roughly a -22dB WSPR signal. This seems to be about the limit of where a QRSS signal can be seen properly.

The really interesting signal though is the 100 milliawatt one. If you know the QRSS callsign in advance, you can infer the relevant information from the fragments on the screen even when the signal is much lower.

As an aside, I did see a very weak sawtooth waveform as ell during the opening.

I'm assuming for now that it was just some sort of local interference but I took a screenshot of it just for reference.

Low Band VHF... After seeing a report on Twitter about US fire traffic on 33 MHz, I had a quick look and I did come across a weak unidentified signal on 33.900 MHz. I think I was too late though and the band was closing at that stage.

QRSS reception reports on 28 MHz - Fri 29th May 2020

Friday the 29th of May 2020 was an extraordinary day with widespread Sporadic-E across Europe. While the various VHF bands up to 144 MHz were open, I spent some time listening for QRSS signals (very slow visual morse code) on 28 MHz.

To put the European stations heard in context, first see the map with distances below...

a) First Grab... The short skip on 28 MHz started early and I heard the usual stations near London, roughly 650kms.

M0BMN is a lot further west and as he is just 430kms away, I had trouble getting a good trace of his QRSS signal.

b) Doppler... This is another screen grab later on. Note the double trace on some of the signals.

Pay special note to the signal from G0FTD. On the left, it's weak but clear. On the right, there are two distinct signals from him. The upper trace is steady and is almost as if that signal is coming from a stationary Sporadic-E cloud. The lower trace starts to diverge more over time as if it that signal was coming from something moving at speed and creating doppler shift.

I suspect it was coming from a Sporadic-E cloud that was in motion and half-ways through the second trace, it either reached a point or ionization level that it no longer supported propagation.

The other theory might be that it was aircraft scatter although I still prefer the moving Sp-E cloud theory.

c) Iceland... There was also some good Sporadic-E conditions to the north and I got a screen grab from TF3HZ in Iceland for the first. time.

I also noted a signal up higher in the band but I'm unsure who it is? The amount of Frequency Shift Keying (FSK) seems to be lower than the rest.

(Update: The mystery signal is LB3AH in Oslo, Norway).

d) TF3HZ & M0GBZ clashing... In this screen grab, note the signal from TF3HZ. At first, he is in the clear and on his own. Then the short skip to the east improves and I note that TF3HZ in Iceland and M0GBZ near London are actually on the same frequency.

On a band where there are just 10 or so Hertz between stations, it's easy to end up on the same frequency as someone else especially if they are from a different area.

(Update: The mystery signal at the top is probably an image of G0FTD. The mystery signal at 620 Hz is LB3AH in Norway)

As this second grab shows, they were clashing for quite a while as the conditions were excellent.

e) M0GBZ in the clear again... In this grab, you can see how on the left, TF3HZ in Iceland and M0GBZ to the north of London are still clashing. I then lose the path to Iceland and the signal from M0GBZ becomes clear again.

f) Trans-Atlantic... VE1VDM... All of the QRSS signals from Europe are via one-hop Sporadic-E. To cross the Atlantic, the signal needs several Sporadic-E hops.

As I'm on the north-west edge of Europe, I'm within two Sporadic-E hops of Vernon, VE1VDM in Nova Scotia in Canada.

I first noticed VE1VDM's signal on WSPR on 28.1246 MHz and he transmits a QRSS signal as well just below it. He sends the letters VDM and the weak signal is shown below...

Vernon also transmits a QRSS signal on 28.0008 MHz where the European stations are...

And that mysterious signal again?!?

During another grab, there was a brief opening to G6NHU near London and I could see that VE1VDM was almost on the same frequency.

Towards the bottom of the screen, there is a very faint record of the signal from OK1FCX in the Czech Republic. He sends a signal that has three levels so it can be easy to identify even if the signal is too weak to decode.

In conclusion... Another good day for QRSS signals on 28 MHz and it's interesting to note the way signals change over time. As noted in a previous post, I believe QRSS is the only mode where you can actually see the propagation changing visually.

At this stage, I'm running out of new stations to catch! I think I have seen most of the European stations at this stage.

Links...
1) Report from MW1CFN for 28 MHz QRSS signals heard in NW Wales on the same day.