G0KTN Amateur Radio - 2026 current projects and technical notes

  Do Higher HF Bands Stay Open Later at Solar Maximum? What “later openings” really mean - and what the data actually shows It is sometimes said that during solar maximum the higher HF bands “stay open later”. Some will nod in agreement, recalling evenings when 15 metres lingered unexpectedly, or when 12 metres produced signals well past the time it normally fades. But what does “stay open later” actually mean? Later than average? Later in the season? Later compared with solar minimum? And is this a consistent effect, or simply a memorable one? Using CW Reverse Beacon spot data covering late August 2024 to December 2025 (the peak and early decline of Solar Cycle 25), this article takes a look at how higher HF bands behave toward the end of the day at solar maximum, and separates genuine effects from selective memory. What operators usually mean by “open later” In everyday jargon, “open later” tends to describe one or more of the following: Signals still present after l...

  The Early Decline of Solar Cycle 25 What changes first and why amateurs often notice it before the models do Solar cycles do not end with a bang. They fade. After the excitement of solar maximum - lively higher HF bands, frequent openings, and a sense that “everything is possible” the decline phase begins quietly. There is no clear date when the cycle turns. Instead, small changes creep in, often noticed first by operators who spend time listening rather than watching indices. Using CW Reverse Beacon spot data covering late August 2024 through December 2025, this article looks at how the early decline of Solar Cycle 25 reveals itself on the HF bands , which changes appear first, and why amateur observations frequently detect them before formal models or forecasts catch up. Decline is not the opposite of ascent It is tempting to think of the solar cycle as symmetrical: what improved on the way up should simply reverse on the way down. In reality, the decline phase behaves...

Geomagnetic Disturbance and HF Propagation Correlating solar storms with what a UK Reverse Beacon actually hears Geomagnetic storms are often reduced to shorthand phrases: “bands disturbed” , “conditions poor” , or simply “Kp too high” . While these descriptions are not wrong, they hide an important reality: geomagnetic disturbances affect HF propagation in structured, repeatable, and physically explainable ways . Using CW Reverse Beacon data, covering late August 2024 through December 2025, spanning the peak and early decline of Solar Cycle 25, this article looks at how different HF bands respond during geomagnetically quiet periods versus disturbed periods, and how those responses align with well established solar terrestrial physics. Geomagnetic storms are not “more solar cycle” A useful starting point is to separate two solar influences that are sometimes confused. The solar cycle primarily affects HF through radiated output (EUV and soft X-rays), raising or lowering ov...

  Winter vs Summer on 40 Metres Why season often matters more than the solar cycle During the peak of Solar Cycle 25, many operators noticed something that at first seemed puzzling. Solar activity was high, higher HF bands were lively, and yet 40 metres often behaved very differently depending on the time of year. Winter sessions produced long runs of workable DX, while summer daytime operation could feel noisy and unrewarding despite excellent conditions elsewhere on the spectrum. This contrast is not an anomaly, nor a failure of the solar cycle to deliver on 40m. It reflects a basic reality of HF propagation: on 40 metres, seasonal effects often dominate behaviour more strongly than the solar cycle itself . Using CW Reverse Beacon spot data covering late 2024 through the whole of 2025, this article looks at how and why winter and summer produce such different 40m experiences, even under broadly similar solar conditions. What operators commonly notice Most experienced HF op...

  Solar Maximum and Lower-Band Absorption Why 40 metres does not simply improve at solar maximum Each solar maximum brings a familiar expectation among HF operators: if the Sun is more active, surely all bands should benefit. When 10 metres begins producing regular and sometimes spectacular openings, it is natural to assume that 40 metres will also improve in some obvious and sustained way. In practice, that expectation is often disappointed. Many operators find that daytime performance on 40m remains unchanged, or even feels worse, during periods of high solar activity. Using spot data sent to the Reverse Beacon Network (RBN) spanning late 2024 through 2025, this article looks at why that experience is not only common, but entirely consistent with how the ionosphere behaves near solar maximum. The simple intuition - and its limitation The intuitive picture most of us carry is straightforward: more solar activity produces more ionisation, more ionisation should improve...

  Following the MUF Up and Down the Bands What a Reverse Beacon Node heard during the peak of Solar Cycle 25 Most of us don’t experience propagation through charts or indices - we experience it through habits. We notice when 10 metres wakes up late in the morning, when 12 metres hangs on longer than expected, or when 40 metres starts to sound better as the higher bands go quiet. We may talk about MUF, but we usually recognise it through band behaviour rather than numbers. Between late August 2024 and December 2025, my Reverse Beacon node (which runs continuously 24/7/365) logged a vast number of CW spots across the HF amateur bands from 40m through to 10m. This period conveniently spans the recognised peak phase of Solar Cycle 25 and the months immediately after. Because the receive site remained unchanged (same location, same antenna, same general noise environment), the dataset provides a stable way to look at how MUF behaved day-to-day through solar maximum. What follows is...