While it might seem outdated by some of the more modern digital modes like WSPR or FT8, what is really interesting about QRSS is that you can visually see the propagation moving around.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.
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Screen grab 1.....
In this image above, you can see all of the signals. G0FTD has two transmitters and is the weakest.
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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.
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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.
2 comments:
Thanks for this John. By far the most interesting post I've read anywhere in a while.
Guess I'll be on 28MHz today, then! Enjoy tomorrow's winds!
That's a very well written description of the event, thanks for documenting that. The link between the position of the transmitting stations, the movement of the E reflecting layer and the visualization on the grab is really interesting.
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