It would seem that I left out "analog" in "none of the D-STAR repeaters that I know of (ICOM) have the ability to do " ANALOG " FM repeat. I'm not confused ..my fingers drop words at times....<;-) I was in paging for many years we did both..."ANALOG" and digital paging FSK NRZ...but D-STAR uses GSM, FSK and QPSK as well to send data, acording to the published standard that I have red.
AC0Y --- In [email protected], Gary <[EMAIL PROTECTED]> wrote: > > Coy, > it seems you are confusing technologies here. D-Star repeaters and the > analog repeater systems you are accustomed to are all FM and all > conventional. D-Star is a digital audio format, that's all. It still > operates on an FM carrier. What I think you mean to say is that the D-Star > repeaters do not pass an analog audio FM signal as well as a D-Star > digital audio FM signal. I also wish they did this. > > In the U.S. land/mobile industry that uses the P25 digital audio format > this is known as "mixed mode" (a term Motorola coined). I agree that Icom > missed the boat when they did not build this feature into the new D-Star > repeater systems. Perhaps they were unable to overcome some technical > barrier, I don't know and they won't say (neither Icom or Icom America). > > Also, as you pointed out, D-Star digital voice is a narrowband signal > occupying only about 6Khz vs. the 25Khz or so that amateur repeaters have > often required to date. It is difficult to do a comparison between a > digital audio system like D-Star and a conventional analog system so what > my friends and I have done instead is we programmed several channels in > our D-Star radios with the same simplex frequency only one channel is set > for "DV" (D-Star digital voice) and another is set for narrowband analog > while a third is set for wideband analog. We have performed numerous > point-to-point (simplex) comparisons under varying conditions (day, night, > clear, rain, dry, humid, etc.) so that we could each hear the differences > for ourselves. Under some conditions analog works just fine and certainly > sounds more natural but under other conditions, especially long distance, > the digital voice can make communication more readily possible by audio > compression and virtually eliminating the path noise that we usually hear > on a distant analog signal. > > I frequently use P25 conventional, D-Star, and analog equipment and while > the D-Star format and its error correction abilities may not be the best > it does a very good job and I hope more amateurs explore this digital > voice format and, I hope more amateur equipment manufacturers offer D-Star > capable gear. Soon I hope to try out the European TETRA digital format for > more comparison and education. These are the voice modes of tomorrow so I > think it's in my best interests to learn them today. > 73, > Gary > > Coy Hilton wrote: > > > This brings some questions to mind. none of the D-STAR repeaters that > > I know of (ICOM) have the ability to do FM repeat, If the repeaters, > > antennas and the rest of the equipment weren't the same or nearly the > > same and coo-located how can the test be fair? Also the D-Star is > > narrow band with respect to the standard Fm repeater. With digital > > either it's there or it's not. > > > > Granted digital is a good way to go but it is way too pricy right now > > for me to think of purchasing I'll stick with my FM machines for now. > > > > AC0Y > > > > --- In [email protected], "Ron Wright, Skywarn > > Coodinator" <mccrpt@> wrote: > > > > > > hi all, > > > > > > In the FILES section of this board is a Weak Sig D-Star demon by > > > WB9WZB. Most impressive test. > > > > > > Can anyone give details of the test...was same rig with power levels > > > and antennas used in the test??? > > > > > > 73, ron, n9ee/r >
