[time-nuts] TIC resolution impact on GPSDO's performance
Poul-Henning Kamp
phk at phk.freebsd.dk
Tue Dec 26 08:18:13 EST 2006
In message <20061226.125102.1723212534.cfmd at bredband.net>, Magnus Danielson wri
tes:
>harmonic(2)
>1a) a tone in a harmonic series
>2) in physics, a component frequency of a harmonic motion that is an integral
> multiple of the fundamental frequency
>
>overtone
>1b) Harmonic(2)
Overtone is a musical term and it is not the same as harmonic.
An harmonic frequency is N times the fundamental, where as an
overtone merely holds a rational relationship to the fundamental
(3/2, 4/3 etc.)
The reason you can tell the difference between a violin and a
clarinet is that they have different overtone spectra.
A somewhat arbitrary subset of an intruments overtones are called
"formants" because they are the principal "formers" of the instruments
sound.
>synchronous
>1) happening, existing or arising at precisely the same time
>2a) going on or operating together at exactly the same rate
> b) recurring together
>3) involving or indicating synchronism
>4) in physics, having the same period or having the same period and phase
Close, but no cigar.
If they merely have the same period/frequency, they are "syntonous",
but if the phase is also coincident, they are synchronous.
>asynchronous
>not synchronous, proceeding at its own pace;
But just because two signals are asynchronous, doesn't mean they cannot
have the same frequency or phase for a shorter or longer period of time,
it just means that there is no mechanism that makes it so.
>The "asynchronous" serial line is actually anisochronous BTW.
No, each transmitter and receiver are anisochronous, but the
communication between them, and by language extension the actual
cable, is asynchronous.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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