The three "never repeats" options are generated fresh each time you hit Send — nothing to memorize. The others are fixed reference text.
This text stays in your browser — it's only used to generate the audio.
Demo mode: this is pattern-matched, not a live AI model — no network calls, no cost. Your message sends first in Morse, then the reply sends back in Morse too. Try greetings, thanks, "good copy", "what are you up to", weather (flavor text, not a real forecast), band conditions, your callsign/QTH/rig, "roger", farewells, simple math, or time/date questions.
Farnsworth spacing (send at higher character speed, extra gap between letters)
Radio static (background band noise, all modes)
Signal fade (slow HF-style strength drift, all modes)