SDR as the Station's Ears

Overview

Everything so far has been about getting the station to talk. The next build is about getting it to listen. Two software-defined receivers, a wideband one and a clean HF one, turned into a dedicated listening layer that feeds the parts of the station that already exist.

This is a roadmap, written before the build, so the thinking is on the record. It is all receive-only.

The guiding idea

The best use of SDR here is not a standalone toy. It is to produce data that nothing else in the station can, and route it into what is already there: the propagation page, the mesh gateway, the emergency-communications mission.

What it will do

• An activity map. Sweep a range and log signal strength over time into a heatmap, so a glance shows where traffic lives and when, instead of scrolling the bands by hand.
• Listen and transcribe. Run received voice through local speech-to-text and keep a running transcript of what the station hears. Computed on the station, not in the cloud.
• Keyword alerts over the mesh. Watch the transcript for words that matter, and when one appears, push an alert out over the mesh to a handheld in the field. A quiet station that taps you on the shoulder when something is said.
• Propagation you measured yourself. Decode the weak-signal beacons and digital modes on HF to show what your own antenna is actually hearing, right now, instead of a forecast built from other people’s reports.
• Weather alerts to the field. Decode the official weather-service alert tones and push a warning out over the mesh the same way.

Why it fits

Each of these feeds something already built. Self-measured reception makes the propagation page honest. Keyword and weather alerts ride the same mesh command path that already reaches the field. The activity map tells the rest of the system where to point. The station stops being only a thing that transmits and becomes a thing that also watches.

More on this as it gets built. That is the next chapter.