I find it very interesting that this entire discussion, under more than one thread already closed by Andy (thank you sir) that the main discussion is to the legality of spread spectrum in the HF bands, without a real understanding of the actual technical definitions/differences between spread spectrum vs PSK. Since the real modulation scheme of ROS is actually a form of FSK or PSK ( which does indeed cause the actual transmitted frequency to "shift" based on the modulation signal present at any given moment). Someone please explain to me the difference. If ROS is "illegal" simply because the author happened to "call it spread spectrum" in his papers, then I suspect we have far more problems than this discussion even begins to touch on. As has been said repeatedly in these threads, Olivia, JT65a, and various other FSK modes could just as easily be "called spread spectrum" and suddenly by those "rule book quoters" be declared illegal. However, they are not. They are rightfully called PSK, such as BPSK, 31PSK, etc. Heck, for that matter, if you wished to get real technical, the very method of modulating any form of SSB becomes a slight form of FSK
YES, "the rule book" (part 97) does say "spread spectrum" is illegal below 222 mhz, however, it does not get into the details of precisely what spread spectrum is, nor does it discuss the method of modulating it so as to define the difference between PSK and spread spectrum. These discussions become quite lively every single time a new mode surfaces (remember SSTV, digital modes in general, etc. etc. etc.) Each time the very same discussion ensues all quoting some text from the part 97 without regards to whether it really applies or not. Then the discussion begins around the rules rather than the legitimacy of the discussion to begin with. Thanks Andy for recognizing the circular propensity of some of the other threads discussing the same thing. As to whether the ROS mode is illegal or not, I have no clue, nor do I pretend to, nor do I care. I suspect that the intent of the FCC rules is to preserve and protect the bands, and I do know that experimentation is more than just expected or tolerated, but is virtually mandated by the very nature of our hobby/service by law. John KE5HAM --- In digitalradio@yahoogroups.com, "expeditionradio" <expeditionra...@...> wrote: > > Given the fact that ROS Modem has been advertised as Frequency Hopping Spread > Spectrum (FHSS), it may be quite difficult for USA amateur radio operators to > obtain a positive interpretation of rules by FCC to allow use of ROS on HF > without some type of experimental license or waiver.
