--- In digitalradio@yahoogroups.com, Dave Ackrill <dave.g0...@...> wrote: > > Does anyone have a definition of real spread spectrum? As I hate to > think what will happen when/if people with even less knowledge than I > have of what 'real' spread spectrum is get the idea that RIO is > something that it is actually not and start their inevitable campaign of > 'It's illegal, it's immoral and it makes you fat', to use the words of > the song... > > Dave (G0DJA) >
Well, as a G0 its perfectly acceptable that you don't know. The K's N's W's and A's have no such excuse. Lets check out 47CFR2.201 and see what type of signal ROS is. The first letter is modulation. Clearly its F Frequency modulated. I read the ROS PDF and its basically a 16FSK that has its carrier frequency modulated/wiggled in a peculiar pattern. The number is "nature of signal(s) modulating the main carrier". Clearly its 2, "A single channel containing quantized or digital information with the use of a modulating sub-carrier, excluding time-division multiplex". That sub-carrier is the 16FSK, which thankfully (?) isn't TDM data. The second letter is "type of information to be transmitted". Well, obviously that is D for data. We're not sending "E" voice or "A" telegraph or whatever here. So, the overall "FCC Emission designator" would pretty obviously be "F2D". Where can we run F2D? First, hit FCC 97.305(c) "authorized emission types" table. The FCC says SS only on 222 and up. I have no idea what inspires people to publically claim you can only run SS on 432 and up, as 97.305(c) explicitly permits it on 222 and up. For another example, on 30M we can do RTTY or DATA. How does "DATA" or "RTTY" or "SS" or "PULSE" relate to emissions designators? The FCC helpfully defines that in 97.3(c) To qualify as SS all it needs per 97.3(c)(8) is "Spread-spectrum emissions using bandwidth-expansion modulation emissions having designators with A, C, D, F, G, H, J or R as the first symbol; X as the second symbol; X as the third symbol." F2D doesn't seem to match the def of "SS". To qualify as DATA all it needs per 97.3(c)(2) is "Telemetry, telecommand and computer communications emissions having (i) designators with A, C, D, F, G, H, J or R as the first symbol, 1 as the second symbol, and D as the third symbol; (ii) emission J2D; and (iii) emissions A1C, F1C, F2C, J2C, and J3C having an occupied bandwidth of 500 Hz or less when transmitted on an amateur service frequency below 30 MHz. Only a digital code of a type specifically authorized in this part may be transmitted." F2D doesn't seem to match the def of "DATA". Looks like USA folks can't transmit ROS at all, on any band. Ooops. Will people fooling around with ROS get dragged to court? Probably not. See 97.305(b) "A station may transmit a test emission on any frequency authorized to the control operator for brief periods for experimental purposes, except that ... (essentially no SS or pulse where not otherwise permitted)". So, fooling around for testing and experimentation of a new mode is well within the law by this exception. Running a contest, a regular schedule, a formal net, DXing, QSL card collecting, county hunting, or extensive ragchewing would be strictly verboten under 97.305(b). The key is doing it in a documented manner as an experiment, like as a research experiment or an article for QEX. Realize that big brother can deprive you of your life and liberty at any time for any reason, its not as if a rule prevents that, it just claims Big Bro won't do it, and politicians never lie... In summary, the problem seems to be FM modulating the carrier of the 16FSK. 73 de Vince N9NFB
