[Ham-80211] HSMM: 420-430 MHz
kb9mwr at gmail.com kb9mwr at gmail.comFri Mar 4 20:34:26 UTC 2011
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Here is some explanation from the QEX article, for those concerned: In 47 CFR 97.315 the emission type "image" is defined as including "emissions having B as the first symbol; 7, 8 or 9 as the second symbol; W as the third symbol". In 47 CFR 2.201 (c) (2) a first symbol of B defines the type of modulation of the main carrier as an "emission in which the main carrier is amplitude-modulated (including cases where sub-carriers are angle-modulated) with independent sidebands". The OFDM modem fits this description as it has a central carrier with multiple subcarriers in the upper and lower sidebands that are angle (phase) modulated. In 47 CFR 2.201 (d) (5) a second symbol of 7 indicates that the nature of the signals modulating the main carrier are "two or more channels containing quantitized or digital information". 47 CFR 2.201 (d)(2) and (3) indicate that time-division multiplex is excluded for a single channel so the time division multiplex inherent in HSMM communications creates two or more channels. In 47 CFR 2.201 (e) (8) a third symbol of W indicates that the type of information to be transmitted is "a combination of the above" and that includes (4) "facsimile", (5) "data transmission, telemetry and telecommand", (6) "telephony" and (7) "television". HSMM fits this definition as it includes data, speech and image components. I am more concerned by underutilized spectrum, and red flags that people throw that deter experimentation in the hobby. That said I have a few extra picture frames and would be fine framing my first "pink slip" over silly rules in the name of experimentation. I firmly believe that the rules will change as we do.
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