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 »
Mostly during the morning hours around sunrise, FT8 beacon transmissions can be heard on the 60 metre band. The purpose of these transmissions is to collect data for a propagation study. This is an ongoing project. An article which was published April 2021 is found here. Examples of graphs are found on page 5. An… Continue reading »
Our radio friends in New Zealand informed me that the article on 60 metre propagation was published in the NZART magazine “Break-In”. Below, a link to the article as I submitted it. 60_metre_EU_ZL_propagation_PA2S Summary (taken from the longer version of the study) The author, radio amateur, became intrigued by ionospheric propagation during the late 70’s… Continue reading »
With the development of the new solar cycle, conditions are changing. This is nothing new of course, but a distinct effect was found, that is really puzzling. Compared to last year, signals from Europe to New Zealand are not much different, but SNR reports of ZL stations are considerably weaker now. Using Proplab Pro, ray… Continue reading »
The past few years, a lot of time was spent into analysing ionospheric propagation on 60 metres. A number of observations were published on this website showing very remarkable effects, of which signal peaks at specific times were most pronounced. These peaks occur during openings from Europe to the Oceanic region. Long path propagation to… Continue reading »
Similar to the recent retraction of the permits in New Zealand, the ACMA decision not to support amateur use of the 60 m band in Australia is a slap in the face. Invalid arguments and even secrecy were brought forward to support the decision. Why is 15 kHz of spectrum with only 15 Watts radiated… Continue reading »
Today, I received very sad news about expiry of the 60 m trial licenses in New Zealand. On October 24th, the 60 metres band in New Zealand will become silent. I very well remember the first contacts back in January 2018 and at the time, I did not know about the very good propagation between… Continue reading »
Having read about WSJT-X version 2.3.0 with the new FST4 protocols, curiosity drove me to perform some tests. In the past, I wrote about FT8 and the fact that its sensitivity is considerably less than JT65 or JT9, leading to lost DX opportunities. Especially on 60 metres, the restricted power levels pose an additional challenge… Continue reading »
Regular readers of this blog know that noise (interference, to be correct) from various sources is my most prominent nuisance. A few weeks ago, I stayed for a weekend on a rural location in France and took my IC706 and antenna with me. A wire antenna was put up, using a tall tree and two… Continue reading »
An excellent opening to New Zealand was observed on 11 February 2018. The station was switched on around 0700 UTC and several ZL stations came in with good signals. At some point, I decoded 4 ZL stations at the same moment and the 4 calls shown on JT Alert was an unique and impressive experience…. Continue reading »