Jerry Avins wrote:> santosh nath wrote: > >>I guess Shannon is the father of information theory , digital >>communication >>and many more - he is a real genius and unparallel figure of all time! >> > Hero worship is likely to warp one's perspective. The first digital > communications systems I know much about were Napoleon's wig-wag > telegraph with left and right standing for one and zero, and Amerindian > smoke signals, which were made by moving a blanket ON and OFF. > > As Glen wrote, digital modulation came first because it's easier.I don't know how old the Native American signaling is, but I read the Romans regularly used a chain of hilltop sites for communication. They waited until night, then sent messages by obscuring and revealing a fire with a large cloth. They probably used some of the same hilltop sights now owned and managed as communial aerial facilities, by such companies as Aerial Facilities Ltd. Regards, Steve
Digital modulation!!
Started by ●July 7, 2003
Reply by ●July 8, 20032003-07-08
Reply by ●July 9, 20032003-07-09
santosh nath wrote:> Hello all, > Can anybody tell the key motivation of the inventor (who is the > genius behind it?) to use digital modulation instead of its analog > counterpart and how did it happen historically and experimentally? > > Regards, > SantoshMarconi came first or was it Samual Morse? Tom
Reply by ●July 9, 20032003-07-09
I guess Marconi invented radio transmission, not digital modulation... "Tom" <somebody@nOpam.com> ha scritto nel messaggio news:3F0B98BE.543E3713@nOpam.com...> Marconi came first or was it Samual Morse? > > Tom > >
Reply by ●July 9, 20032003-07-09
Marconi's first efforts were interrupted carrier wave telegraphy. Pretty much the most basic form of digital modulation, wouldn't you say? (Unless someone can come up with something more basic :-) ) Ema wrote:> I guess Marconi invented radio transmission, not digital modulation... > > "Tom" <somebody@nOpam.com> ha scritto nel messaggio > news:3F0B98BE.543E3713@nOpam.com... > > >>Marconi came first or was it Samual Morse?Does Morse's telegraphy count as modulation? I'm not sure. Regards, Steve
Reply by ●July 9, 20032003-07-09
Hello Steve, Heinrich Hertz (who discovered radio waves) would switch his apparatus on and off and notice the comings and goings of a spark in a spark gap on the other side of the room. This predated Marconi and he didn't have a narrow carrier per se. He just let sparks excite a resonant circuit which used huge amounts of spectrum, but since nobody else was using it - it didn't matter. Clay "Steve Underwood" <steveu@dis.org> wrote in message news:behc2v$207$1@hfc.pacific.net.hk...> Marconi's first efforts were interrupted carrier wave telegraphy. Pretty > much the most basic form of digital modulation, wouldn't you say? > (Unless someone can come up with something more basic :-) ) > > Ema wrote: > > I guess Marconi invented radio transmission, not digital modulation... > > > > "Tom" <somebody@nOpam.com> ha scritto nel messaggio > > news:3F0B98BE.543E3713@nOpam.com... > > > > > >>Marconi came first or was it Samual Morse? > > Does Morse's telegraphy count as modulation? I'm not sure. > > Regards, > Steve >
Reply by ●July 9, 20032003-07-09
Ema wrote:> > I guess Marconi invented radio transmission, not digital modulation... > > "Tom" <somebody@nOpam.com> ha scritto nel messaggio > news:3F0B98BE.543E3713@nOpam.com... > > > Marconi came first or was it Samual Morse? > > > > Tom > > > >He demonstrated long-range transmission of Hertzian waves (Hertz is the eponym of our frequency unit) by using the digital modulation scheme invented for the electric telegraph. There were plenty of digital modulation schemes in use before that, most of them related to semaphores of various kinds. The rhythm but not the loudness of jungle signal drums is significant, so I would call that digital also. Sometimes drums of different pitches are used: FSK. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●July 9, 20032003-07-09
> santosh nath asked: > > > Hello all, > > Can anybody tell the key motivation of the inventor (who is the > > genius behind it?) to use digital modulation instead of its analog > > counterpart and how did it happen historically and experimentally?Digital modulation is described in the New Testament (Matthew 5:37) which specifically recommends binary signaling (instead of M-ary signaling with M > 2), and coding with a (2, 1, d = 2) block code, presumably for error detection. The verse in question says (in the King James Version) "But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil." and is part of the Sermon on the Mount....
Reply by ●July 9, 20032003-07-09
ha ha, you're a genius! can I use that verse as my signature? "Dilip V. Sarwate" <sarwate@uiuc.edu> ha scritto nel messaggio news:3F0C4D10.DAA57371@uiuc.edu...> Digital modulation is described in the New Testament (Matthew 5:37) > which > specifically recommends binary signaling (instead of M-ary signaling > with M > 2), > and coding with a (2, 1, d = 2) block code, presumably for error > detection. The > verse in question says (in the King James Version) > > "But let your communication be, Yea, yea; Nay, nay: for whatsoever > is more > than these cometh of evil." > > and is part of the Sermon on the Mount....
Reply by ●July 9, 20032003-07-09
Ema wrote:> > ha ha, you're a genius! > can I use that verse as my signature? > > "Dilip V. Sarwate" <sarwate@uiuc.edu> ha scritto nel messaggio > news:3F0C4D10.DAA57371@uiuc.edu... > > Digital modulation is described in the New Testament (Matthew 5:37) > > which > > specifically recommends binary signaling (instead of M-ary signaling > > with M > 2), > > and coding with a (2, 1, d = 2) block code, presumably for error > > detection. The > > verse in question says (in the King James Version) > > > > "But let your communication be, Yea, yea; Nay, nay: for whatsoever > > is more > > than these cometh of evil." > > > > and is part of the Sermon on the Mount....You think maybe Dilip holds a copyright? There's a fellow out there who uses my sig, but he puts it in quotes. That's enough attribution to make me content. (Actually, I'm flattered.) Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●July 9, 20032003-07-09
"Jerry Avins" <jya@ieee.org> ha scritto nel messaggio news:3F0C4A87.B7F646A8@ieee.org...> He demonstrated long-range transmission of Hertzian waves (Hertz is the > eponym of our frequency unit) by using the digital modulation scheme > invented for the electric telegraph. There were plenty of digital > modulation schemes in use before that, most of them related to > semaphores of various kinds. The rhythm but not the loudness of jungle > signal drums is significant, so I would call that digital also. > Sometimes drums of different pitches are used: FSK.Oh well, he was another italian :-) hey, answer to this quesion please: who invented the thelephone first: A.G.Bell or Meucci? here:http://inventors.about.com/library/inventors/bltelephone.htm In the 1870s, two inventors Elisha Gray and Alexander Graham Bell both independently designed devices that could transmit speech electrically (the telephone). Both men rushed their respective designs to the patent office within hours of each other, Alexander Graham Bell patented his telephone first. Elisha Gray and Alexander Graham Bell entered into a famous legal battle over the invention of the telephone, which Bell won. here: http://www.italianhistorical.org/MeucciStory.htm But it seems that history must be rewritten if justice is to be done to an immigrant from Florence, Italy: Antonio Meucci, who invented the telephone in 1849 and filed his first patent caveat (notice of intention to take out a patent) in 1871, setting into motion a series of mysterious events and injustices which would be incredible were they not so well documented. That's why nowadays there's no Meucci Telecom Company :-(( E.
