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 18th of January, I managed to get a good capture of TF3HZ in Iceland.
On the 17th of January, I had seen the QRSS signal of TF3HZ in between G0MBA and G0PKT so I knew where to look. on the 18th at 12:14 UTC, the signal appeared out of the noise.
This is a good example of how useful QRSS is in that you can 'see' the propagation changing. It shows how within the space of a minute, the path between Ireland and Iceland opened up.
In the next cycle, I got a nice strong QRSS signal and screengrab for TF3HZ.
The path distance was 1576kms so it's hard to know for certain what the propagation mode was. Was it F2 layer? Was it some mid-Winter Sporadic-E? The sudden appearance of the signal is very similar to a lot of the QRSS signals I have seen during the Sporadic-E season but it's not conclusive evidence. I think it's just one of those cases where no-one can be certain which of the propagation modes it was.