David,
I haven't been following this thread so I suppose it has already been
answered, but how are you measuring "zero beat?"
Lee Mushel
----- Original Message -----
From: "David I. Emery" <d...@dieconsulting.com>
To: <j...@quikus.com>; "Discussion of precise time and frequency
measurement" <time-nuts@febo.com>
Sent: Monday, May 07, 2012 5:37 PM
Subject: Re: [time-nuts] Oh dear
On Mon, May 07, 2012 at 08:28:41AM -0700, J. Forster wrote:
A crummy crystal oscillator zero beated to WWV is good to 1 in 10E6, a Rb
disciplined to GPS maybe 1 in 10E11.
Do you seriously think you, or anybody, can hear a pitch difference of
0.001 Hz in the audio range?
A quartz crystal is plenty good for any audio application, IMO.
-John
I completely agree, and far more significant than accuracy
is jitter (phase noise) in maybe the tenths of a Hz to thousands of Hz
area. This does modulate the sampled sound and perhaps is perceptable
at very low levels.
BUT Cesium, or Rb buys nothing in respect to phase noise
in those ranges... really good quality quartz oscillators have much better
close in phase noise than many Rb's or Cesiums...
What Cesium and Rb buy is good performance measured over much
larger taus... which cannot possibly have any impact on human hearing.
--
Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass
02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole -
in
celebration of what could have been, but wasn't and is not to be now
either."
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