Hi Kevin, Perhaps it might help to use the ITU three symbol Classification of Emissions?
The first symbol considers the main carrier modulation with letters such as A = DSB AM, B = independent sidebands, etc. This would give you the AM modes and the F = FM and G = PM modulation types. Then they include the second symbol which is the nature of the signal that is modulating the main carrier such as 0 = no modulation, 1 = quantized or digital signal with no subcarrier, 2 = quantized or digital signal with sub carrier and 3 single analog channel. Finally, they include the third symbol or type of information to be transmitted such as N = no information, A = telegraphy using manual aural reception, B = telegraphy using machine automatic reception, C = facsimile, D = Data, telecommand, telemetry, E = telephony, F = TV, etc. The various digital modes are really a combination of base modulation with the addition of a quantized signal, plus the type of information. The only modulation that hams typical use are AM and FM/PM and if digital modes are used, they are superimposed on the base modulation. Hope that might shed some light on the matter. 73, Rick, KV9U Gmail - Kevin, Natalia, Stacey & Rochelle wrote: > Hi All, > > I am hoping with the number of members in this group that someone > might be able to answer my question. > > Many years ago, as we know radio started off with CW, then AM was > developed, with an improvement to only use one part of the AM carrier > to produce SSB with carrier or SSB suppressed carrier. > Then somebody developed FM. > Now in my view this gives 4 actual modes? > But I see you say (Maybe), we have all the digital modes. But are > these actually modes? > Why I ask and the reason for the question, is these are still using > one of the current 4 above, over a SSB carrier for the likes of > PSK-31, SSTV etc, or FM for the likes of Packet. > So will the future be able to bring us anything new that will improve > the usablility of radio? > Doing a search on Google brings up thousands of hits, but none > actually answer the questions, most also class each digital type as a > mode. > Would be very interested in your thoughts. If you do not feel this is > the fourm to reply, a direct email to sparcnz(nospam)@gmail.com will > be fine. (please remove the (nospam) before sending, I am trying to > limit the amount of spam) > > Regards and thanks for looking at this thread. > > Kevin, ZL1KFM. >
