PhosphorPSK

PhosphorPSK turns your iPhone into a real-time PSK31 decoder with the look of a Cold War signals terminal.

Hold it to your radio's speaker, or patch the audio in, and watch the text appear on a glowing phosphor screen — amber or green, your choice, scanlines and all.

PSK31 is the mode that put keyboard-to-keyboard chat on the HF bands in a bandwidth barely wider than the signal itself. PhosphorPSK decodes it, and its faster cousins PSK63 and PSK125, straight from the received audio. No cloud, no account, no dependencies. Everything runs on the device.

DECODING
- Real-time BPSK demodulation: PSK31, PSK63, PSK125
- Locks onto the strongest signal in the passband — isolate the one you want by tuning your radio, the way you always would
- Canonical Varicode, decoded exactly
- Holds up well down to low signal-to-noise ratios

SIGNAL DISPLAY
- Live FFT spectrum with carrier cursor
- Scrolling waterfall
- BPSK vector scope — watch the constellation snap into place as it locks
- Carrier, SNR, level and lock readouts

BUILT FOR THE HOBBYIST
- Session log: every decode saved, searchable, shareable
- Adjustable input gain
- Automatic strongest-signal lock, or set the carrier by hand
- Amber and green phosphor themes, CRT glow and scanlines
- iPhone, portrait, one clean screen

PhosphorPSK is receive-only — a listening and decoding tool for shortwave listeners, amateur radio operators, and anyone who likes watching text pulled out of the noise. No transmit, no licence required to listen.

Part of the Phosphor family of receive-only decoders, alongside PhosphorRTTY (radioteletype), PhosphorCW (Morse) and PhosphorSSTV (slow-scan images). Same CRT phosphor, different mode.

On a busy band, narrow in with your radio — PhosphorPSK reads whichever signal is loudest. Tune to a PSK31 signal, point your phone at the speaker, and read the bands.