Showing posts with label G6NHU. Show all posts
Showing posts with label G6NHU. Show all posts

Thursday, May 21, 2020

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While it might seem outdated by some of the more modern digital modes like WSPR or FT8, what is really interesting about QRSS is that you can visually see the propagation moving around.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

Tuesday, April 2, 2019

QRSS signals heard on 80 metres - 1st Apr 2019

I follow a number of blogs and sometimes I read something which sparks my interest. One such item was the recent post by G6NHU about QRSS... a mode where morse is sent at very slow speeds and the signals are seen on a computer screen rather than being listened to.

I spent some time on this mode before but it was back in 2011. I had assumed that with the introduction of newer digital modes like WSPR and FT8, QRSS had probably died out. I seem to remember listening to a podcast some time back which said as much.

After reading G6NHU's post, I was suprised to find that there is still plenty of QRSS activity and there is also a very active QRSS community on Groups dot io.

G6NHU has a detailed list of QRSS frequencies and they seem to be strategically positioned just below the WSPR frequency on some bands.



The net result of this is that it's possible to use the WSJT-X programme to listen to WSPR signals on say 80m and also look at the QRSS signals on the waterfall display at the same time.

Examples of QRSS signals heard on 80m - 1st Apr 2019

This is the waterfall on the WSJT-X programme rotated 90 degrees. The dashes and dots in morse for G0FTD can be seen.


Some are a bit more elaborate with full call signs shown... see OK1FCX below.


Some have gone a bit further and their signals show up as complex images like fish!


... or maybe it's a dolphin? :o)

And another fish but this one looks a bit like a shark...



Also TF3HZ as shown below. Sometimes it's a case of taking a few screenshots and then trying to put the pieces together.



Some Links...
http://www.g6nhu.co.uk/frequencies.html
https://groups.io/g/qrssknights
https://qsl.net/g0ftd/other/74%20-%20Knights%20QRSS%20Winter%20Compendium%202018.pdf