The QRSS Gallery

Using QRSS enables us to see some amazing effects on our signals which we would not normally be able to detect easily on other modes. Here's some useful grabs to help identify what is happening should you see the effects yourself.  Normally QRSS signals would have a nice clean visual / straight lines etc. But that all changes when we get various ionospheric effects. This is a guide to spotting them. My eternal thanks to those of you who provide grabbers and signals to monitor. Without you this fascinating view of radio would never exist.  Interested - then have a look at AJ4VD's excellent write up on the hobby and also the resources at the end of the page. Let's start with some 10m meteor scatter and  auroral effects.  (Note, the pics are still copyright of their respectful owners, for whom I have permission to reproduce). Other examples can be found in my 74! compendium here.

The first set of grabs as we call them show six signals that have been reflected by an incoming meteor entering the ionosphere, known as meteor scatter mode. The last three show auroral propagation effects and it's also interesting to note that there's  a slight apparent lowering of the transmitted frequencies too for some reason. Multipath echos are also seen with Doppler shift. All these signals were transmitted from Kent and Essex in south east England and received by G0MQW in Reading,Berkshire.,UK.

Here is  some multipath on 80m during greyline propagation.  You can see ground wave and sky wave signals on slightly different frequencies. The textual identification of G0FTD is done using a mode called Slow Hell that is provided by the QRP Labs Ultimate series of rig

Next up are CME's or coronal mass ejections from the sun. They have the effect of causing the frequency of signals to vary upwards slightly as the ionosphere thickens and is extended closer to the Earth. The grabs are from W4HBK, G6AVK and PA0TAB.  The first  signals are from the  UK on the 10m band. The others from G6AVK and PA0TAB  on 10Mhz.  They ALL show up the ionospheric disturbance as an upturn in the signal frequency before signals fade out (Sudden Ionospheric Disturbance). Once the Ionosphere has recovered so do the signals with nice neat lines of course. See how the apparent frequency of the transmitted signals rises.

Greyline propagation on 40m from TF3HZ to G3VYZ in northern England. Just look at that Doppler frequency spread.

Next up is some more meteor scatter effects on 10m. Usually forward scatter mode and the transmitters are about 150 miles away from the receiver. Meteor scatter has also been observed on the 10Mhz (30m) band on numerous occasions too.

Here's a grab from LA5GOA on the 30m band during an aurora in 2015. Just look how it's destroyed the WSPR and QRSS signals and how the frequency is pulled about all over the place ! It's one of my all time favourite grabs. The grab below it is a typically normal grab that shows how WSPR signals (top) and QRSS signals (lower) should look.

Here's a grab from G0MQW that shows how strong aircraft reflections would look. You can see both the primary signal and the Doppler shifted reflections moving in frequency as the aircraft approaches and departs. Sometimes depending upon location of TX and RX, you will ONLY see the aircraft reflected signals and not the direct ones.

Ever heard that "North Pole wobble" effect on HF SSB when working Hawaii, Alaska sometimes the West Coast USA ? Well as the signals pass through the auroral oval they become dispersed and attenuated. Large amounts of Doppler shift can be observed (that's why the HF SSB audio sounds weird). We can see this effect with QRSS quite clearly. Here's a mild example using the signal from TF3HZ seen in Alaska. Note that this gives pretty much the same effect as grey line can do. You can tell what the mode or propagation effect is by observing the time it occurs.

More general QRSS grabs showing daily activity. Some Slow Hell transmissions, FSKCW and "Slant"on 30/10m bands. The last grab courtesy of EI7GL  was during an experiment that I was conducting with regards to how the ionosphere dictates the final polarisation and fading. If you look at the top of the grab, you will see G0FTD and G0FTD-H. One is a horizontal loop, the other is a quarter wave ground plance antenna. Both are fed with 500mw of RF.  You can see that both traces "track", which means that the ionosphere will take in any polarisation but IT decides what the "output" polarisation is. This varies all the time, and it is this that results in the fading that we observe. Note that this grab is just one of many that showed the same results.

Please bear in mind that these grabs or captures where taken at "perfect" times during a particular day or part of the solar cycle. The majority of the time you could be staring at blank grabbers for months (like 10m) waiting for something to happen, or experiencing summer doldrums on the mid HF bands, when DX is poor due to higher E layer ionisation (although that's when Sporadic E is good on 10/6m). It takes real dedication to play QRSS. There are no instant results.

Lastly, here's a grab taken by OK1FCX on the 50Mhz band of G0PKT in Essex, UK. The TX is 1 watt output and the receiver is a simple RTL SDR Dongle and a Raspberry Pi for the processing. Mode of propagation is Sporadic E (Sp E) and note what appears to be echo'd traces (multipath).

Here's a general grab supplied by Mike G6GN, below, which shows how easy it is to get a very low powered signal our on QRSS. The receiver was a remote controlled Kiwi type located in South Australia. You can see my 500mw to an indoor wire loop antenna with a weak trace, G6GN and finally M0PWX with a dipole just above his fence panels !

Some superb bit of DX supplied to me via G6GN via remote SDR in New Zealand. My bedroom wire antenna,  a 25mw balloon over Greenland, G6GN and ON4CDJ can be seen. Amazing stuff. Thanks Mike.

And some amazing DX on 10m from WD4ELG and K5MO showing signals from UK/EU/NA. Remember folks that transmit power is typically 500mw to wire antennas.

And here's some interesting Doppler shift effect on G0FTD as received by G6GN, about 200 miles north of G0FTD. That's a lot of Doppler as the signal is being badly diffused by the ionosphere at the time on 40m. Transmitters was 300mw and a simple 30ft horizontal wire at 5m a.g.l

25Hz of Doppler / diffusion is quite a lot, and often the sort of levels that you would expect from an over the pole transmission. If that had been an SSB transmission then the voice signal would have sounded very ghostly!

By comparison, the signal at the bottom from S52AS is looking "normal". Under normal propagation, the signal from G0FTD would the same and as clean.

It's October 2023. Here's some signals as received in ZL2 land. PA2ST and G0FTD and a massive signal fro HS0ZHB / NM7J on 20m via a Kiwi receiver in Kiwi land! All done using about 200mw and bits of wire for antennas.

And another great stacked grab from K5MO on 10m in Jan 2024. Amazing signals into what is known as The Can. The Can is John's grabber built into an old ammo can and thrown at the end of his garden. Mentioned in the 74! Compendium back in 2020. Also available here.

Further resources:

AJ4VD's website - https://swharden.com/qrss/plus/

G0FTD's alternative website - www.qsl/net/g0ftd/grabber.htm

G0FTD's Youtube channel with QRSS animations - https://www.youtube.com/user/MrRadiouser/videos