ETDs, PCs, PDAs & cellphones vs tuning fork : how accurate are they ?

[Philippe Errembault]

Hi all,

I hope this is not annoying you, but I posted this question under
another topic and there was no answer... So I suspected that this
topic had become a little long and most stopped reading it.
I just hope it wasn't me that people stopped reading...
Am I annoying someone ?

So... the question was

Do you usually have an idea of the precision of the A440 reference
you use ? I mean... I didn't get any the precision information with
my tuning fork, I found it on the net.

I wonder what are the precisions of professional ETDs, and what
precision we can expect from a pocket PC, about which I wonder
if it even can be as precise as a normal PC...

In fact, I have one reason to think it could even be better : since
this material is intended to be as small as possible, it might be that
they only contain ONE reference clock, for time, for CPU and for
sound processing. Then, we could expect the sound precision to be
as precise as their time clock... did any of you ever tried to check his
pocket PC, against a good A440 reference, and compare the error with
the time drift ? (and optionaly, compare it with a desktop PC)
Reminder : 0.1cent = ~0.0058% = ~5sec/day

Philippe Errembault

Ps : There was also someone who claimed that listening a tone reference
through a cellphone was as good as with a normal phone. I know the
buffering of cell phone is small, but this doesn't change the fact that any
shift in it's clock should be retrieved in the output ! this would lead to
an
interresting experiment :
take two cell phone, call the same tone reference and see if there is any
beat between them... I'm quite curious about the result !