Digital modes

Pick an input above the tabs:

FT8 decodes each 15-second UTC slot 0.4 s after it ends: time, SNR (dB in 2500 Hz, an estimate), DT (time offset), audio frequency and the message, with the sender’s country (AD1C’s cty.dat) and, if you give your locator, the distance and beam heading to the grid in the message. Messages to your call are highlighted; CQs are green. FT8 needs your computer’s clock within about a second of UTC — Clock offset corrects it. The decoder is a port of Kārlis Goba’s ft8_lib (MIT licence, licence): over its 31 test recordings it finds 352 of the 354 messages ft8_lib finds (WSJT-X, with more decoding passes, finds more).

PSK31 — click a trace on the waterfall (or type its audio frequency); AFC follows drift. RTTY — click between the mark and space traces; 45.45 baud and 170 Hz shift are the amateur standard (Reverse if the text is garbage). CW uses the Morse code tool’s decoder. Send makes PSK31 and RTTY audio from text, to play or save as WAV.

SSTV listens for the VIS header that starts a picture, then draws Martin M1, Scottie S1 or Robot 36 pictures line by line, following small clock errors on each sync pulse; received pictures can be saved as PNG. Send turns a picture (or a test card) into SSTV audio.

WSPR & PSK Reporter maps where a callsign was heard (or what it heard): WSPR spots come straight from wspr.live; PSK Reporter’s reports need the gitwebsite app’s companion, because pskreporter.info sends no CORS headers (it also asks for no more than one query every five minutes).

Full screen (⛶ Full screen or F; Esc leaves) enlarges the tab’s waterfall, picture or map.