[sdiy] Software to log frequency every x seconds?

[Derek Holzer]

Most computer frequency analysis programs aren't simply comparing the 
input frequency to a crystal. Often they are using Fast Fourier 
Transformation analysis, which means that the signal is being chopped 
into tiny "windows" and these windows are then checked for their 
individual sinusoidal components. In each window, you have a "bar", or 
"bin", which represents each of the sinusoids it will look for (power of 
two numbers, i.e. 256, 512, 1024, 2048, 8192, 16384, etc etc). Higher 
frequency resolution means less accurate time resolution, and 
vice-versa, but in general the results you get from FFT are very reliable.

FFT for Dummies: http://www.vlf.it/fft_beginners/fft_beginners.html

One of the more ideal softwares for what you want to do is called Baudline:

http://www.baudline.com/

However it's Linux only at the moment. You might Google around for a 
good spectrum analyzer/spectrum analysis software for your platform of 
choice. Many will have the ability to record the FFT data over time so 
you can see drift. Perhaps some other list members have favorites already...

best,
derek

-- 
derek holzer ::: http://www.umatic.nl ::: http://blog.myspace.com/macumbista
---Oblique Strategy # 139:
"Revaluation (a warm feeling)"