What Solar Cycle 25 Has Taught Us
What Solar Cycle 25 Has Taught Us
And why amateur data really does matter
Solar Cycle 25 has turned out to be a surprisingly instructive cycle. Not because it has broken records, but because it has unfolded at a time when amateur monitoring networks are mature, widespread, and actually quiet powerful.
For me, one of the clearest lessons from this cycle has been that long-term, systematic amateur observations can reveal propagation behaviour that is subtle, nuanced, and genuinely informative, often before those changes become obvious in summary indices or prediction models.
This short series has touched on MUF dynamics, absorption effects, seasonal modulation, geomagnetic disturbance, late-day high-band behaviour, and the early signs of decline. Each article has been grounded in observation rather than theory alone, and all of it has come from a single, consistent source of data.
The value of simply listening - all the time
Every article in this series has been based on data gathered by my Reverse Beacon Network (RBN) node between late August 2024 and December 2025. In its present configuration the system runs continuously, 24 hours a day, 365 days a year - listening for CW across all amateur bands from 160m through to 10m and reporting reception spots to the RBN.
That continuity matters. A receiver that never sleeps captures transitions, marginal openings, and failures just as reliably as it captures the obvious “good” conditions. Over time, this produces a dataset that is far richer than it might first appear.
It also removes a great deal of human bias. The receiver does not know when conditions are supposed to be good. It simply reports what it hears.
Why local data matters
One limitation of the RBN is that once spots have been uploaded, they cannot be retrieved from the network. The system is designed for real-time awareness via DX Clusters, not long-term research.
However what makes analysis possible at all is the local spots.txt file created on the node itself, ie the shack PC running Skimmer server software. This file contains the complete history of uploaded spots and becomes, in effect, a private propagation archive.
Without that file, much of the longer-term behaviour discussed in this series would be invisible. With it, it becomes possible to revisit earlier periods, compare quiet and disturbed days, examine seasonal effects, and correlate band behaviour with solar and geomagnetic events.
Running an RBN node does require a fair amount of commitment and careful setup, and it is not for everyone. Fortunately, there are other - much easier - ways to contribute.
WSPR: propagation science made easy
For anyone interested in propagation but not keen to run a full RBN node, WSPR provides a remarkably accessible alternative and in many ways a more powerful one.
Crucially, WSPR is already built into WSJT-X, a program that many amateurs are already using daily for FT8, FT4, and related modes. There is no additional software to install and no specialist knowledge required to get started.
If you already run WSJT-X, then you are effectively one menu option away from running WSPR.
WSPR is far more sensitive than CW and routinely detects propagation paths well below the noise floor. More importantly, all WSPR data is archived at WSPRnet.org, making it available for future analysis in a way that RBN data generally is not.
WSPR is not just for “checking antennas”
There is a persistent misconception that WSPR exists mainly to “check antennas”. While it can certainly be used for that, such a view misses the real point.
A WSPR station, transmitting or receiving, is a distributed ionospheric sensor.
Run continuously, it can reveal:
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band performance over time
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seasonal and diurnal structure
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responses to geomagnetic disturbance
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solar-cycle evolution
By running WSPR you are not just learning about your own station. You are contributing to a global scientific dataset that others can analyse now and in the future.
You don’t even have to transmit
It is worth emphasising that receiving stations are just as important as transmitting stations. Without monitors, nothing gets spotted.
Running WSPR in receive-only mode is easy, effective, and genuinely useful. It requires no RF output, minimal hardware, and provides immediate value to the wider amateur community. Much of what we understand about propagation comes not from calling, but from listening - carefully and consistently.
For those who prefer an off-the-shelf, unattended solution, there are now excellent standalone options available, such as the transmit beacons and separate receivers produced by ZachTek, which remove much of the setup complexity.
Turning data into understanding
Once you have accumulated hundreds, or more likely thousands, of WSPR spots, the natural question becomes: what do you do with them?
Services such as WSPR Rocks!, run by VK7JJ, make it straightforward to retrieve your own data as CSV files. From there, several paths open up:
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spreadsheet analysis
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scripting and custom tools
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correlation with solar and geomagnetic indices
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comparison of antennas or locations
Increasingly, there is another option.
Uploading such datasets to an AI system allows exploratory analysis that was once difficult to achieve outside academic environments. You can ask about band behaviour during specific storms, compare seasonal performance, or request structured technical summaries of your station’s behaviour.
Used sensibly, AI becomes a tool for asking better questions - not a replacement for thinking.
There is still much to explore
It is true that WSPRnet already contains billions of spots, but those spots are heavily concentrated on the traditional HF bands.
There remains enormous untapped potential on the lower VHF bands:
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10 m
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8 m
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6 m
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4 m
WSPR activity on these bands is still sparse, and that scarcity is exactly what makes new contributions valuable. Stations operating here are not just helping today’s operators - they are creating datasets that future researchers will rely on to understand long-term propagation behaviour.
This series has shown that with modest equipment, patience, and a willingness to look beyond day-to-day operating, radio amateurs can explore genuine propagation science - often with insights that complement, and occasionally anticipate, formal models.
If your interest leans more toward understanding why the bands behave as they do then tools like RBN and WSPR provide a way to make a real contribution. Coupled with modern analysis tools, including AI, they open doors that were once firmly closed outside academia.
The ionosphere is still there, changing every day, and for many amateurs, everything needed to observe it is already running on the shack PC.
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