28 Jul
2019
28 Jul
'19
10:05 p.m.
Yes, both were patented technologies. Most every modern radio has a lot of licensed intellectual property, from microprocessors to modulator circuits to displays ... On Sun, Jul 28, 2019, 21:09 Nick Kartsioukas <nick@explodinglemur.org> wrote:
As for FM and SSB, I may be missing something in their history, was there a time when an amateur radio operator was legally prohibited from developing their own SSB or FM modulator or demodulator without paying a licensing fee to some entity?