24 Sep
2005
24 Sep
'05
8:19 p.m.
This is exactly the type of discussion that I was hoping to stimulate.
The accuracy issue is paramount to the success of this project. A
reference source is something that I had been considering. Wondering if
a standard source could be used to calibrate the program initially so
that resultant measurements could be done without the reference being
present.
Not sure I understand the references to a 'pro' card vs what might be
available in a standard MB based sound card or laptop as portability may
be a desired feature for use outside the repair shop. Can one of you
clarify a little? I am new to some of this terminology.
Thanks - TheCapn.
On Sat, 2005-09-24 at 23:24 +0200, fons adriaensen wrote:
On Sat, Sep 24, 2005 at 11:31:39PM +0300, Jussi Laako
wrote:
On Sat, 2005-09-24 at 19:22 +0200, fons
adriaensen wrote:
For a 'pro' card that would do the trick, provided you *have* an accurate
clock generator. But pendulum clocks being big, heavy and difficult to move,
one would prefer to have this sort of app on a laptop. If you could find some
frequency reference that can be input as an audio signal on a second channel,
that would be ideal - no jitter to deal with. There are some cheap portable
clocks that sync to a broadcast time service. Maybe it's possible to extract
a usable signal from these.
(not extremely precise either), or some external
timing reference,
e.g. a 1 Hz pulse from a GPS receiver, or a reference frequency.
One way I've used is to feed more accurate reference clock to the word
clock input of some pro sound card. Some reference clocks can be
programmed to output some specific frequency.