Hi Differential signaling does indeed take care of a bunch of stuff. The gotcha is that both sender and receiver need to agree on levels and stuff like that. Most of these logic families have pretty short life spans if you include supply voltage dependant stuff. Could you work it out over the decades - yes. Would it be a pain to do 1960's style stuff today - yes again.
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of paul swed Sent: Monday, February 06, 2012 9:15 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Why a 10MHz sinewave output? Indeed the long cable runs are tough. Though today we have differential cable drivers that do quite well to the Ghz range. But certainly back in the dark ages the sine wave was a very reasonable way to go. Regards Paul On Mon, Feb 6, 2012 at 3:56 AM, Attila Kinali <[email protected]> wrote: > On Sun, 05 Feb 2012 19:50:28 -0800 > bob grant <[email protected]> wrote: > > > Why is 10MHz output of many sources or distribution amps in the form of > > a sinewave? > > Is it something to do with signal reflections or ease of isolation? > > > > Since zero crossing detectors are susceptible to noise wouldn't a fast > > TTL square > > wave be more appropriate for signal distribution within a equipment > > rack? > > The advantage of a sine wave is that you have a single, bounded frequency. > A square wave has quite strong components at odd multiples of the base > frequency, theoretically going up to infinity. To get a "good" shape > of the signal you need at least the first three of the harmonics, resulting > in a seven times increased bandwidth need. > > Beside of the more complicated handling of the higher frequency components, > you also have to think about dispersion of the signal if you go trough > filters or use longer cables. > > Attila Kinali > > -- > The trouble with you, Shev, is you don't say anything until you've saved > up a whole truckload of damned heavy brick arguments and then you dump > them all out and never look at the bleeding body mangled beneath the heap > -- Tirin, The Dispossessed, U. Le Guin > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
