I woke with a compulsion to take a look at 3cm overnight. Unfortunately at 01.00 local time not even I am not at my best mentally so it took a while to figure out what I was seeing. I still do not know whatI saw to be honest.
This shows a few features worthy of note. The dish was point at PI7ALK so it’s signal on 10368.898.880 is a good and strong with some slow fading. This qsb qas to be my undoing.
GB3PKT was also strong pn the same heading at -13dBjt, and the other regular visitor, PI7RTD was also the nest signal I have seen from it for a long while.
What is odd and it may not be clear on this image, there are three additional beacons. The first on 10368.824.000 (MGM), second one on 10368.904.000 (cw only) and a third on (about) 10368.972.500 (MGM).
My comprehensive listings fail to show any beacons on those frequencies. I think the MGM beacons are JT4G rather than PI4 but that doesn’t help.
There is also a smudge, if you look carefully with one eye closed and eyes screwed up tight whilst hanging from the ceiling…..so it is by no means certain that there is a signal on 10368.810.100.
As I thought the signal might have been SK6YH/B from Goteborg I moved the dish in that direction fully expecting to see an increase in signal amplitude.
Sadly it was not to be and by the time I finished thoroughly checking headings (azimith and elevation) by the time I set the dish back on PI7ALK all three additional beacons had disappeared with PI7ALK rapidly disappearing. It was as if the green curtain was being drawn to hide the Wizard.
By 0100utc the band was back to its neutral state. Even GB3PKT had dropped back to -16dBjt. No other signals, not even PI7ALK were audible/visible.
Obviously I caught the back end of an enhanced propagation event bu have been left frustrated (for now) as to the identity of those unidentfied beacons.
As I write this at 0730utc the band it quiet, as quiet as it was after 0100utc. Wave height in the southern North Sea remains at about 2m so there is no prospect of evaporation ducting. There is a troposcatter signal from PI7ALK so at least I know the system is working
Given the location of the thicker band it may be possible to see something from DB0GHZ although unlikely as the layer would have have an altitude of about 4km for the scatterpoint to be above the horizon. As the huge change in Dew point temperature for Helgoland occurs at about 650hPa (~3500m asl), this places the altitude at which scattering could take place below my horizon.