KM4SPL Amateur Radio

Built by Mike Hutson · KM4SPL

Radio projects.
Ready to explore.

Tools for the shack, experiments for the field, and a place to follow the work as it develops.

In development · by KM4SPL

Digital Command Center

A station dashboard for FT8, FT4, JS8, WSPR, PSK31, and RTTY, with radio setup and a growing set of digital operating tools.

Start in your browser

Your test station is ready.

Explore a simulated radio with a matched antenna. Select a caller, adjust your RX and TX audio offsets, and follow a sample contact from CQ to the session log.

Launch interactive demo →Read the full help guideExplore downloads
  • Six digital-mode simulations with mode-specific timing and dial presets
  • 313 Hamlib radio choices and model-specific setup settings
  • Independent RX/TX markers, retained receive history, and collapsible panels
  • Simulated transmit, tune, TX drive / ALC, and contact logging
  • Station profiles and preferences saved in your browser

Help, built into the site

Get comfortable at the controls.

A complete, searchable guide to the demo, station setup, every digital mode, and common problems. Read it here, download it, or print a copy for the shack.

Your first contact →Radio setup →TX Drive / ALC →Troubleshooting →
Open the complete guideDownload full help document ↓

Published files

Downloads & setup

Try the demo immediately, or run the new decoder source preview on your computer. The older Windows Alpha remains available below.

New · Python source preview

Multi-mode Decoder Preview

Windows / Linux · Python 3.11+ · Receive-only

Decode FT8, FT4, and WSPR with WSJT-X engines. Bring in JS8Call activity and fldigi PSK31 / RTTY text through their local APIs. Includes decoder setup, WAV recording tests, RX filtering, and saved mode settings.

Requires Python and the decoder apps you want to use. This is source code, not a one-click Windows executable.

Download decoder source ↓
Decoder installation & setup guidePlain-text decoder notesDecoder preview checksum
What has been tested?

Real WSJT-X sample recordings produced 22 FT8, 19 FT4, and 9 WSPR decodes. JS8Call and fldigi integrations passed local TCP / XML-RPC protocol tests. Full JS8Call / fldigi audio playback and physical radio reception still need field testing.

The browser demo uses synthetic messages and tones. WSPR demonstrates receiving propagation beacons; it does not simulate a two-way QSO.

Windows 10 / 11

Digital Command Center — Windows Alpha 1

Portable ZIP · 20.4 MiB · Receive-only preview

Extract the ZIP, then run DigitalCommandCenter.exe. CAT and FT8 decoding are still being completed in this build.

Download Windows Alpha ↓
Download quick-start guideView SHA-256 checksum
Verify your download

The hosted ZIP matches this SHA-256 checksum:

5fa3a94d5a9bf2e4241b8f09da39894961627e82bfc4ec02bafd9bc1e566bfa1

On Windows, run:

Get-FileHash .\Digital-Command-Center-Windows-Alpha.zip -Algorithm SHA256

The source preview includes Linux / Raspberry Pi setup instructions. A prebuilt Raspberry Pi package is not yet published.

Good to know

Before you start

Does the demo connect to my radio?

No. It runs a simulated station in your browser. The radio catalog lets you explore settings without hardware. Choose a digital mode beside the band selector; use Next cycle to skip the wait.

Will my station information stay saved?

Yes, in the same browser and device. Profile edits save automatically. Private browsing or clearing site data can remove saved details.

What do the waterfall markers control?

Green selects the receive audio offset within the selected mode's dial frequency. Red selects the transmit offset. Click for RX, Shift-click for TX, drag either marker, or enter an exact offset. The demo RX pane shows messages within ±50 Hz of the selected receive offset.

Which download should I choose?

Use the decoder source preview for current receive integrations and local WAV tests. Use the browser demo to explore operating controls without installing anything. Windows Alpha 1 is an earlier packaged build and does not include the new multi-mode decoder integrations.

Around the station

More KM4SPL resources

Local repeaters ↗

Find the repeater and EchoLink resources on the station page.

Callsign & logbook ↗

Visit the QRZ profile and public logbook links.