A priori is a Latin phrase which – in the context of FT8 etc. – translates to prior knowledge. This article aims to explain what a priori decoding does. It also discusses how AP relates to a “valid QSO”. A little paragraph is dedicated to to information theory. The article also illustrates that AP is… Continue reading »
On the 31st of October 2024, we had a good opening to North America on 6 metres. Lots of stations active with FT8, but I checked classic modes as well. On about 50.110 just before 1300 UTC, N1BUG was working EU stations, initially rather weak. But the signal increased and reached S9 levels. After a… Continue reading »
April 2023 was less “productive” when compared with March. The F2 electron density at moderate to high latitudes is greater during winter than in summer, especially at times of enhance solar activity [1]. This implies that the F2 critical frequencies become lower towards the summer season in the northern hemisphere. During previous cycles, most openings… Continue reading »
March 2023 was an interesting month. It reminded me of March 1979, when first 6 metre amateur signals were heard. After many times trying, I was amazed to hear the ZS6PW beacon on the 12th of March. The station consisted of an indoor dipole on the attic, connected to a converter from 50 to 14… Continue reading »
There were times that reports were collected by editors of newsletters. PA0BN edited the Dutch VHF bulletin for many years and my observations were sent to him to merge with those of other active amateurs. The newsletters were a joy to read. Nowadays, there are many blogs and fora, resulting in a lot but distributed… Continue reading »
There were times when there was only one type of amateur radio licence. One had to pass a technical exam and a Morse code test, because telegraphy was the standard operation mode. Later on, a separate licence became available without the Morse test and only gave access to VHF and up. My first exam was… Continue reading »
The last few days, conditions on 6 and 4 metres were quite good. Even with my modest station, some nice DX was worked on 6. Back in 1989, I became rather frustrated because I had ‘half a QSO’ in CW with CO2KK. He unfortunately took my call as PA2HJH instead of PA2HJS and I was… Continue reading »
A few days ago I worked PJ7/W9DR for a new entity on 6 metres. In the past, the entity was deleted because of the change in governmental structure. The contact with PJ7/W9DR was greatly appreciated! Looking W9DR up on QRZ.com led me to a nice video of his water cooled 6 metres amplifier, that runs… Continue reading »
After putting up the 5+5 element YU7EF 6/4 metre dual band antenna, I was curious how the new antenna performs. Although I realise that a real measurement requires quite a bit of effort, a simple comparison between the new antenna and an antenna with a more or less known performance at least gives a clue… Continue reading »
Last week, I put up a dual band antenna for 6 and 4 metres. It was difficult to decide what to build. Last year, I had separate antennas for both bands. Dual band antennas are attractive, because of lesser wind load and also because it leaves some room for other antennas. Another aspect was that… Continue reading »