KA9NWM — Built By A Ham
Watch the greyline move.
Helioclock started as a way to keep the propagation picture visible without digging through browser tabs. The greyline, the DX Cluster, a full propagation toolkit, and a working station display, all on one screen.
Greyline Propagation
Dawn and dusk are prime time.
The greyline — the band of twilight circling the globe — is where the ionosphere shifts and long-distance contacts open up on the low bands. Helioclock tracks the terminator continuously and shows it on the world map, with a pass-quality gauge and a 7-day greyline window calendar for your own station, so you know when it’s crossing a path you want to work.
Propagation & Space Weather
The numbers that actually predict a contact.
BAND CONDITIONS
80m–10m Status
Color-coded open/marginal/closed status for every HF band, day and night, driven by live SFI and Kp.
MUF MATRIX
Maximum Usable Frequency
A live MUF estimate across 8 world regions and 9 bands.
PROP FORECAST
3-Day Propagation Grid
A 9-band by 3-day forecast grid, plus an azimuthal view of propagation paths from your station.
DRAP
D-Region Absorption
Per-band HF absorption severity, so you know which bands a radio blackout is actually hitting.
SOLAR ACTIVITY
Live NASA SDO Imagery
Real-time solar imagery across six wavelengths, plus a 30-day sunspot number trend.
AURORA
Aurora Visibility
The NOAA aurora oval mapped live, with a visibility check for your own latitude.
Exclusive to Helioclock
Best Band Now: prediction that checks itself.
Most propagation tools show you a model prediction, or live spot data — never both compared against each other. Best Band Now checks a live MUF prediction, anchored to your own QTH, directly against real DX Cluster and RBN activity, and flags it whenever they disagree. A band predicted closed but confirmed active anyway is the single most useful signal a propagation tool can show you.
4-STATE LOGIC
Confirmed, Likely, Surprise Open, or Closed
Evaluated at your own station’s coordinates, not a generic world region. Surprise Open is the one no other tool flags.
LIVE CONFIRMATION
DX Cluster + RBN, With Hysteresis
Confirmation from real spot activity, with a hysteresis rule so a band doesn’t flicker between states over a one-spot difference.
DECISION LOG
A Track Record, Not Just A Guess
Every best-band pick change is logged, retrievable via a simple API, so you can judge the tool’s own reliability over time.
On The Bench
What’s actually built for the shack.
DX CLUSTER
Live Spot Feed
A scrolling feed of DX spots with band filters, so you can see who’s active at a glance.
AZIMUTHAL
Bearing & Distance
Centered on your own grid square, showing true bearing and distance to any DX station — built for pointing a beam.
CW TRAINER
Morse Practice
Sending practice (you key, it scores you) and receiving practice (it sends, you copy), with a Koch-method training sequence. Connect a key or paddle via audio input, USB HID keyer, WinKeyer, or direct Raspberry Pi 4/5 GPIO wiring.
PTT
On-Air Banner
A visible on-air indicator wired to your station’s PTT line, with callsign, band, and a TX timer. Detects PTT via direct Raspberry Pi 4/5 GPIO, or a USB serial adapter on any hardware.
WWV
Time Standard Markers
WWV/WWVH reference markers on the map with a propagation rating for the path.
CALLSIGN
Station ID Display
Your callsign and grid square, shown right on the display — a real station clock, not a generic one.
POTA / SOTA / WWFF
Activator Tracking
Live Parks on the Air, Summits on the Air, and World Wide Flora & Fauna activations, with dedicated map layers.
RBN
Reverse Beacon Network
Live automated beacon spots, feeding directly into Best Band Now’s live confirmation.
PSK REPORTER
Digital Mode Reception Reports
See who’s copying your FT8, FT4, or PSK31 signal in real time.
DXPEDITIONS
Current & Upcoming DXpeditions
A running list of active and upcoming DXpeditions worldwide.
CONTEST CALENDAR
Upcoming Contests
Point it at your own feed URL to keep upcoming operating events on screen alongside everything else.
Beyond The Basics
Tools most displays don’t bother with.
EME
Moon Bounce Planning
Enter a remote station’s grid square to see live moon position for both stations, a 24-hour overlap window timeline, and a link budget calculator across 6m through 23cm.
NCDXF BEACONS
International Beacon Project
The live 18-beacon rotation across five HF frequencies, highlighting whichever beacon is transmitting right now — no internet required.
MAIDENHEAD GRID
Grid Square Overlay
Field and square grid lines on the map, with a live 6-character locator readout anywhere you hover.
ISS / AMSAT
Satellite Pass Prediction
Live ISS ground track and configurable AMSAT satellite tracking, with next-pass time, elevation, and a polar diagram.
QUICK REFERENCE
Built-In Desk Reference
Band plans by license class, antenna and RF formulas, Q-codes, phonetics and CW prosigns, coax loss tables, and a component reference — all one keystroke away.
Coming Later
Where this is headed.
A few things planned for after launch, once the core product is in operators’ hands:
- Operator Honor Roll — an opt-in map of registered stations running Helioclock worldwide
- Live ADS-B flight tracking via RTL-SDR
- Full DXCC flag graphics in the DX Cluster feed
- WWV/WWVH live audio receive and CW/RTTY decode, via an SDR add-on
Meet Us In Person
Huntsville Hamfest 2026
Helioclock will be exhibiting at the ARRL National Convention, August 22–23, at the Von Braun Center in Huntsville, Alabama. Stop by and see it running live.