2024 10m QRSS Challenge: - M0GBZ & G0FTD in England - 3rd June

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year. On the 3rd of June, I added M0GBZ and G0FTD to the tally during a short skip Sporadic-E opening at about 16:00 UTC. 

The map below shows the location of the stations shown in the screen grab above.

TF3HZ in Iceland is a relatively easy catch at 1576kms and I got a screengrab of his signal back in January. The stations near London in the east of England are about 560 to 650kms from my location and require the skip distance for the Sporadic-E opening to be shorter than usual.

Getting good screen captures for both M0GBZ and G0FTD is quite difficult for me. It's not really the distance as it's June and there are plenty of short skip openings on 28 MHz. The problem is that the signals from G0PKT and G0MBA are so much stronger.

This is my usual screen grab during a short skip opening...

My sound card in the PC seems to get overloaded by the signals from G0MBA and G0PKT and I get a screen of false signals. If I adjust the audio levels to a low enough level to get rid of these false signals, M0GBZ and G0FTD disappear.

What happened on the 3rd of June is that there was a very small footprint for the Sporadic-E signal.

The footprint of a Sporadic-E opening tends to be in the shape of an oval and as suggested by the image above, the footprint favoured both M0GBZ and G0FTD with G0MBA and G0PKT being at the edge of the footprint.

This meant I could get good QRSS signals from both M0GBZ and G0FTD while the signals from the G0MBA - G0PKT duo were weaker and not overloading my sound card.

What's really interesting about this is the relatively short distances between these stations. G0FTD is at the south side of the Thames Estuary while the G0MBA - G0PKT duo are at the north side, a distance of about 50 kms.

From my location on the south coast of Ireland which is about 650kms to the west, I could see how the small Sporadic-E footprint allowed me to hear stronger from one side of the Thames Estuary compared to the other side.

This is a nice example of just how small and localised Sporadic-E openings can be. You can hear big signals from a particular station and someone a short distance away hears little or nothing.

This gets even more pronounced for higher frequencies like 50 MHz, 70 MHz or even 144 MHz.

QRSS... It also shows how QRSS (slow morse code) signals allow you to 'see' the propagation moving. With modes like WSPR or FT8, you either get a decode or you don't. 

With QRSS, you can see the propagation moving in real time. Several times during short skip openings, I have seen QRSS signals disappear in the space of a minute as the Sporadic-E footprint moves.

In summary... That brings the QRSS tally so far for 2024 up to 23-callsigns & 10 DXCC.

1) 8th Jan 2024: VE1VDM - DXCC #1
2) 10th Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2
4) 15th Jan 2024: G0PKT
5) 15th Jan 2024: AE0V - DXCC #3
6) 16th Jan 2024: RD4HU - DXCC #4
7) 16th Jan 2024: W1BW
8) 17th Jan 2024: OH5KUY - DXCC #5
9) 18th Jan 2024: TF3HZ - DXCC #6
10) 6th Feb 2024: VA3RYV
11) 16th Feb 2024: IK2JET - DXCC #7
12) 16th Feb 2024: N8NJ
13) 21st Feb 2024: PY3FF - DXCC #8
14) 26th Feb 2024: VE6NGK
15) 27th Feb 2024: NM5ER
16) 28th Feb 2024: VK4BAP - DXCC #9
17) 2nd Mar 2024: WA1EDJ
18) 5th Mar 2024: FR1GZ/B - DXCC #10
19) 30th Apr 2024: IK1WVQ
20) 8th May 2024: IW0HK/B
21) 14th May 2024: IZ1KXQ/B
22) 3rd Jun 2024: M0GBZ
23) 3rd Jun 2024: G0FTD

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.

QRSS Signals from the UK on 28 MHz - Tues 19th May 2020

QRSS is a mode where a morse code signal is sent very slowly so that it can seen on a screen rather than heard by ear. This allows signals that can be up 20dB below the noise level to be seen.

While it might seem outdated by some of the more modern digital modes like WSPR or FT8, what is really interesting about QRSS is that you can visually see the propagation moving around.

On Tuesday the 19th of May 2020, there was really intense Sporadic-E on 28 MHz with a very short skip opening from Ireland to the UK. This allowed me to hear the QRSS signals from stations near London as shown on the map below....

The key points here before we look at the QRSS plots are...

a) G6NHU, G0MBA & G0PKT are all very close to each other and about 650 kms from my location.

b) G0FTD is about as far but is 50 kms to the south of the cluster of three.

c) M0GBZ is along the same path as the group of three but is about 90 kms closer at 560 kms.

d) The shorter the distance then the smaller the Sporadic-E footprint tends to get.

As shown above, it tends to be long and narrow and this will be shown in the QRSS examples below.

***

Screen grab 1.....

In this image above, you can see all of the signals. G0FTD has two transmitters and is the weakest.

***

Screen grab 2...

In this image, the Sporadic-E footprint moves north and even though G0FTD is just 50 kms from the more northern stations, he moves outside the footprint.

The cluster of three remain remain the same while M0GBZ disappears as the skip lengthens for a while before coming back.

* * *

Screen grab 3...

In this plot, the Sporadic-E skip distance increases and M0GBZ disappears. G0FTD disappears for about two minutes before the footprint moves south again.

On the right hand side, all of the QRSS signals are there but they now become quite fuzzy which may indicate multipath. Perhaps the Sporadic-E has broken up into several clouds rather than maybe the single one before.

In conclusion..... This was the my first reception this year of the UK QRSS stations on 28 MHz and as you can see from what's written above, the plots show a lot.

From what I now, the QRSS mode is the only one where you can actually see on a screen how the propagation is moving around in real time.

Listen on 28.0008 MHz on CW for these stations running just a few hundred milliwatts.