Before the evening
Space weather decides a lot. A quiet sun keeps the paths to America open; a solar storm closes them but can open the way south, towards Africa and the Middle East. The app reads the forecast, works out when it gets dark here and across the Atlantic, and suggests which channels are worth trying.
Dusk
As the sun sets, Europe comes in, channel by channel. These are the neighbours: stations from all over the continent that hold their channels all night. They are both company and trouble — an American on 1500 kHz shares the channel with a European a few hertz away.
The middle of the night
When it's dark all the way to Newfoundland, the Atlantic opens, sometimes only for a few minutes at a time. The SDR receiver records the whole mediumwave band at once, while I listen to one channel at a time — or sleep.
A small watcher listens at the same time through remote receivers in Britain and Ireland and says when North America opens. What I hear myself counts. What the remote receivers hear is only a hint about where to tune.
Dawn
When it grows light in the east but is still dark to the west, the American stations can be at their strongest. Then it closes, channel by channel, and Europe falls silent with them.
The morning
The computer goes through the recording: every channel, every minute, every carrier. Each transmitter sits slightly off its channel, and that offset follows it night after night — so it's possible to tell the channel's usual European from something new. Speech recognition listens for station names and towns and puts forward what is worth hearing.
Nothing becomes a log entry until I have heard it myself.
Afterwards
A station heard with its name gets a reception report: the time, what was on air and how the signal sounded. Sometimes a reply comes back — a QSL. The first North American one arrived four days after the night.