[sdiy] Software to log frequency every x seconds?

[Tom Wiltshire]

On 3 Oct 2007, at 02:33, Ian Fritz wrote:

> At 06:35 PM 10/2/2007, Mike Beauchamp wrote:
>>  I'd like to graph the frequency
>> drift over time of VCO's to see how accurate they are, etc. I've been
>> using just a chromatic tuner program on my downstairs computer, and
>> running down and writing down the frequency every hour or so.
>
> Characterizing drift as a function of time is -- IMO -- a waste of  
> time and effort.

Depends what you're doing with it. If you're trying to imitate VCO- 
style drift on a oscillator that can be regarded as stable, then  
knowing what that drift looks like over time is useful. Obviously,  
knowing what the drift looks like over temperature would be nice too.  
Unless we've got some graphs to prove it, I'm a bit unsure about  
saying that VCO drift is due to temperature changes and not time.  
When I looked into this, facts seemed a bit hard to come by, although  
everyone knew what they thought about it!

I've attempted to take readings a different way - by recording the  
VCO audio output into the computer for a while, and then using  
software to analyse the resulting soundfile and plot a frequency  
graph from that. A high resolution audio interface is more or less  
essential.

Regards,
Tom