An RBN S-Meter…

The Reverse Beacon Network is a global array of software-defined radio receivers — “skimmers” — continuously scanning the HF bands and reporting every CW, RTTY, and FT8 signal they hear. Unlike a traditional spotting network driven by human operators, the RBN runs 24/7 and produces thousands of automated spots per hour.

That firehose of data contains something tremendously useful: a real-time picture of which paths on which bands are actually carrying RF right now. The RBN S-Meter extracts exactly that picture and presents it in a form your eyes can parse in seconds.

How It Works

The key concept is your vantage point. You choose your region from a dropdown — say, “E. North America” — and the app polls the RBN live. It filters spots to those heard by skimmers near you, then aggregates signal levels by band and source region. The display updates in real time.

Update: User feedback that regions only were too big an area… a guy in Eastern Canada would be seeing data from clusters in Florida. So I updated the app to allow you to pick your grid square, and a radius distance to a spotter. You can choose a range from 250 to 2500 miles. The danger being if you pick a spotter radius that is too small, you might not see any data.

When you select your region, you’re asking: “What are skimmers located near me hearing, and where are those signals coming from?” The answer tells you exactly which DX paths are open from your part of the world — right now, on which bands, and at what strength.

Each region panel shows a band-by-band S-meter bar. The bar height and S-unit readout represent the median signal level across all qualifying spots, so a handful of loud signals don’t skew the picture. The spot count at the bottom of each panel tells you how much data is backing the reading — S7 on 17 spots is far more meaningful than S7 on 2.

What You See at a Glance

• Region selector — Pick your vantage point. All propagation data is then reported relative to your location.
• Band meters — 160m through 6m, one bar per band, with live S-unit readouts updated each poll cycle.
• World panels — Eight DX regions displayed simultaneously: E. and W. North America, C. North America, South America, Europe, Africa, Asia, and Oceania.
• Spot counts — Each panel shows how many RBN spots are driving the reading, so you know how much confidence to put in it.
• Status bar — Live poll timestamp, raw data volume, and spot/vantage/mapped statistics so you always know what the app is doing.
• No install required — Single standalone Windows x64 executable. No separate runtime, no registry entries.

A Practical Example

Say it’s late afternoon and you’re thinking about working some EU. You glance at the RBN S-Meter. The Europe panel shows 40m at S5 with 28 spots, 20m at S3 with 9 spots, and 15m completely dark. That tells you 40m is your best bet right now, 20m is marginal, and 15m isn’t worth your time. You tune to 40m, find a pile-up, and work it. No guesswork, no wasted time spinning the dial on a dead band.

Now flip it around: you want to know if 10m is open to Japan. Select your region, look at the Asia panel, check the 10m bar. Either it’s lit up or it isn’t. The RBN doesn’t lie.

Built for Radio Operators

This isn’t a general-purpose propagation tool dressed up in ham radio clothing. The RBN S-Meter was designed from the ground up for the way operators actually work — you need information fast, you need it to be accurate, and you don’t want to babysit a web browser while you’re at the rig. The UI is dense but readable, and the controls are minimal: Start, Stop, Reset, Close.

Future versions will bring deeper amateur radio integration, including hardware PTT key support, callsign-based station tagging, and repeater/linked system awareness. But for propagation assessment right now, the RBN S-Meter is ready to go.

RBN S-Meter is a free, standalone Windows x64 application. Download here.
(Latest update 4/17/26 01:20z)

73 de W1VE — comments and bug reports welcome.