Last night, I was looking through Amazon, and stumbled over all the $10-20 "Pixie" type CW transceiver kits... and I started wondering... If I cooked up a new digimode that combined on-off keying with precise timing and self-clocked Manchester coding (or something more sophisticated), would it be legal for a ham subject to US FCC jurisdiction who holds a General class or higher license to transmit, as long as the resulting output waveform would otherwise be acceptable to the FCC if it were a single-tone SSB soundcard digimode? On one hand, the FCC is pretty clear that "A1A" has a very specific definition that includes both "on-off keying" and "International Morse Code" On the other hand, it's also pretty obvious that the FCC regulations use the definition of "A1A" primarily as a regulatory proxy to limit what novice and technician class licensees are allowed to do on HF, and not out of any technical concerns. 1. Most new radios don't really transmit "CW" by keying a carrier on and off... they "fake it" by transmitting a tone as SSB. And on lower-end radios, transmission begins on key-down, and continues (with the tone itself following the state of the key) until a few hundred milliseconds elapse with the key up. So, there's really nothing sacred or holy about toggling the transmitter itself anymore, and no waveform difference between a single tone modulated as SSB, and a carrier switched on and off. 2. As a General-class licensee, I can transmit pretty much any novel digimode capable of being generated by a soundcard, as long as (generalizing a bit) it takes no more bandwidth than SSB phone (upper part of the band) or 1khz RTTY (lower portion), and I don't describe it as "spread spectrum". Presumably, that includes digimodes that would consist of a single tone. Given #1 and #2, it seems like any potential FCC objections to it are satisfied. Does this sound like a reasonable interpretation? Why: I'm toying with the idea of trying to cook up a new digimode that's compatible with CW-only radios, but has FT8-like robustness. If nothing else, it would give me geeky bragging points, and maybe something to list on my resume as a cool development project I worked on. Unfortunately, since point #2 doesn't (presently) apply to Novices & Technicians, a mode like this would probably only be allowed for General class & above. On the other hand, if the FCC finally gets around to giving novices & techs narrowband digimode privileges on all the novice HF bands, I can see modes like this becoming popular, since it would enable you to have a robust digimode that worked with even simple radio kits.