PhosphorHertz
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PhosphorHertz

Stuart Woolley · released 28 Feb 2026 · Open in App Store ↗

Revenue 30d not estimated
Downloads 30d not estimated
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RatingPrice
United Arab Emirates<1%0AED 2.99 $0.81
Afghanistan<1%0$0.99
Antigua And Barbuda<1%0$0.99
Anguilla<1%0$0.99
Albania<1%0$0.99
Armenia<1%0$0.99
Angola<1%0$0.99
Argentina<1%0$0.99
Australia<1%0A$1.99 $1.41
Azerbaijan<1%0$0.99

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Description

PhosphorHz is a real-time HF radio propagation monitor for amateur radio operators. It pulls live space weather data from NOAA's Space Weather Prediction Center and translates it into band-by-band conditions you can act on — right now, from your location.

No guesswork. No stale forecasts. Just the numbers, rendered in a retro CRT phosphor display that would look at home in a Cold War listening post.

BAND CONDITIONS

See at a glance which HF bands are open, marginal, closed, or blacked out. Conditions are calculated from real-time solar flux, geomagnetic activity, and X-ray flux data — not generic regional forecasts. Each band shows your local status plus path-specific conditions to every DX target you configure.

MUF CALCULATION

The Maximum Usable Frequency for a 3000km reference path from your QTH, derived from Solar Flux Index, solar zenith angle, and depressed by geomagnetic activity. Individual MUFs are calculated for each great-circle path to your DX targets, because the ionosphere doesn't care about averages.

SOLAR INDICES

All the numbers that matter, updated in real time:

Solar Flux Index (SFI) with 30-day trend chart

Planetary Kp Index with 24-hour bar chart

Estimated Sunspot Number (SSN)

GOES X-ray flux class and latest flare detection

Solar wind IMF Bz component

NOAA R/S/G scales (Radio Blackout, Solar Radiation, Geomagnetic Storm)

Running A-index and solar wind Bt

Each index includes a plain-language assessment: is the F2 layer well ionised? Is the geomagnetic field quiet or disturbed? Is the solar wind coupling or shielded?

3D GREYLINE GLOBE

A SceneKit globe shows the solar terminator — the boundary between day and night — in real time. The greyline (twilight zone along the terminator) is where lower-band DX propagation is enhanced, and it's rendered as an amber band you can see at a glance.

The globe displays coastlines, your QTH position, DX target locations, and great-circle paths coloured by band condition. Drag to rotate. Double-tap to recentre on your station. Hit play to watch the Earth spin.

SPACE WEATHER ALERTS

NOAA SWPC alerts and warnings filtered for HF relevance. Flare events, geomagnetic storms, radio blackouts — the alerts that actually affect your ability to make contacts, with full detail on tap.

DX TARGETS

Configure up to five target regions. PhosphorHz calculates path-specific propagation for each one, using great-circle geometry and the MUF at the midpoint of each path. What's open to Japan might be closed to South America — and now you can see both at once.

FEATURES

Real-time data from NOAA SWPC (public domain, no API key required)

Band conditions for 160m through 6m

Path-specific propagation to multiple DX targets

3D interactive greyline globe with terminator visualisation

Sunrise/sunset times and countdown to next solar event

Day/night/greyline status at your QTH

Kp index 24-hour bar chart

SFI 30-day trend line

Full space weather alert log with 30-day history

Maidenhead grid locator display

Automatic location detection or manual grid entry

Green phosphor and amber phosphor CRT themes

CRT scanline overlay effect

Designed for iPhone, portrait orientation

No ads. No tracking. No subscription.

Part of the Phosphor suite: PhosphorWX (aviation weather), PhosphorRad (radiation monitoring), PhosphorSol (space weather), and PhosphorOrbit (satellite tracking).

73 de PhosphorHz.