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 8th of May, I got a screengrab of the QRSS signal 'HK' which was sent by the IW0HK/B beacon near Rome in Italy.

Usually, nearly all of the QRSS signals on the 10m band are on 28.1246 MHz and the audio of the signals is about 400-500Hz below the WSPR signals. In this case, the IW0HK beacon was on 28.322 MHz.

In the image above, the fuzzy part of the signal is when it was sending the callsign and locator of the beacon in normal morse code. The QRSS 'HK' part is sent after this.

The beacon runs 1-watt into a vertical five-eight wave antenna.

The map above shows the path and the distance was about 1800kms. The signal was almost certainly via Sporadic-E and it's pretty much the ideal distance for that mode of propagation.

In summary... That brings the QRSS tally so far for 2024 up to 20-callsigns & 10 DXCC.

Robbie, EI2IP reports that there was an unusual opening on the 28 MHz band on the 21st of March 2024. At the moment, the 28 MHz band closes here in Ireland at about 21:00 UTC which is about two hours after sunset. 

Robbie reports working FM4LV in Martinique in the Caribbean on the 28 MHz (10m) band at around 00:49 UTC on the 21st of March which is about six hours after sunset. This is very unusual and raises the question what was the propagation mode?

The general expectation is that all F2 layer propagation should have disappeared six hours after sunset.

FM4LV was on FT8 and there were loads of stations to the west of him reporting his signal. None of these are of interest as they're just the usual F2. These are the stations to the east that heard FM4LV after 00:00 UTC...

The paths to the far south of Spain, Morocco & the Canary Islands are well to the south and are much more likely to have propagation at 28 MHz, even well after dark. The question is how was there a path to EI2IP in Ireland at 52 deg north?

That brings us to the good old dependable Sporadic-E.

Q. How did the F2 layer propagation reach that far north? Answer - An extra hop provided by Sporadic-E.

Q. How is any unusual path possible? Answer - Sporadic-E.

Q. "The propagation chapter in my ARRL handbook doesn't explain how I made a contact?" Answer - Sporadic-E.

Q. Why did my coffee go cold? Answer - Sporadic-E.

OK, I lied about the last one but the point being is that we seem to perhaps use Sporadic-E as an explanation a bit too often. In this case, the opening was at about 1am in the morning in March, not a time noted for Sporadic-E as the Sporadic-E season doesn't start properly until mid-April and it's usually during the daylight hours.

The map above shows the parts of the earth in sunlight and shadow around the time of the opening.

For EI2IP, it's in the middle of the night and six hours after sunset. For FM4PV, it was about two and a half hours after sunset.

When I took a screen grab of this image, I couldn't help notice that the moon was almost directly above Martinique which got me thinking. If the moon is visible to both stations then signals must be reflected off the surface of the moon even at 28 MHz?

In this case, I think the combined antenna gain was probably too low for moon bounce and the answer is probably that the signals came off a layer in the ionosphere. As for the exact propagation mechanism?

When I looked at an online propagation map, it suggested that the path was impossible at that time of day so it's a bit of a mystery.

Conditions on the 28 MHz band have been really good for the last few weeks as can be seen from the map above which shows all of the WSPR stations that I heard from the 23rd of January to the 19th of February 2024.

In total, there are 1334 individual stations which is a lot for a mode like WSPR which after all is just a beacon mode and not designed to make two way contacts. There are a lot of interesting paths in the map but the one I will focus on here are the ones to Australia.

My location in north-west Europe is in the region of 15,000 to 17,500 kms from Australia. While it's not exactly the 'other side of the planet' i.e. 20,000kms, it's still a long way for a 28 MHz signal to travel.

In total, I heard 28 stations from Australia over the 4-week period on 28 MHz. The list is shown below...

I just put up a Fritzel MFB-13, it was generously donated to me by PD9RD. The MFB-13 is a folded back rotary dipole for 10m/15m/20m. The width is only around 2 x 2.1 meters (so total length around 4.2 meters). It’s got a “double” (10m/15m) trap in both elements, while the element length is not even a quarter wave for 10m it’s a compromise on all bands but I’m hoping the directional effect and the height will compensate for that.

The SWR is very acceptable on all bands. Lowest SWR is a bit low on 10m and 15m but way below better than 1:1.5 on the entire band. I’ve tuned the end rods for 20m to have the lowest SWR in the middle of the band and despite of the two traps acting as loading coild on 20m the SWR is better than 1:2 on the entire band and seems to work fine on 14 MHz as well.

I haven’t put it on a rotator yet, it’s now pointing in NE / SW direction and I’ve let WSPR with 1W band hopping 20/15/10 since yesterday afternoon and, results are not bad at all:

Maybe this afternoon I will turn it in N/S direction to see if the picture looks very different.

73 Pleun

 10m remains very active, this is todays activity at 2 different times.

Around 10:30z:

Around 13:55z:

Further details about FT8CN see my Blog https://g1kqh.blogspot.com/2023/02/ft8cn-new-free-android-app.html