Re: gEDA-user: Trouble with an usb oscilloscope

[Joerg <joergsch@xxxxxxxxxxxxxxxxxxxxx>]

Robas, Teodor wrote:

[...]

> I do not have another oscilloscope around so I can only
> guess that the sampling is very low by measuring average
> voltage on the CLK inputs of the converter. And that is
> quite low about 0.5V when sampling is on, and 0V when off.
> 

A trick you can use: Build a 1000:1 or 1024:1 (easier) divider from 
cheap 74HC logic D flip-flops or counters, whatever is there. Hang the 
input to your clock that you want to measure. Divide the output down so 
you get a few ten millivolts amplitude. Feed this into the sound card of 
your PC. Install a free FFT program and start it. If there is a 10MHz 
clock you'd get 10kHz out, if your clock is really only 300kHz your PC 
would show 300Hz.

Now you have one of the cheapest frequency measuring tools possible 
because the PC is already there.

-- 
Regards, Joerg

http://www.analogconsultants.com/



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