[time-nuts] WWVB Simulator

David davidwhess at gmail.com
Wed Jan 4 19:01:57 EST 2017

Not all PC audio hardware includes such a low high frequency cutoff.


Based on the above review, the following cards which are still
available have a response that extends significantly above 60kHz:


On Wed, 4 Jan 2017 21:21:22 +0000 (UTC), you wrote:

>A PC can certainly generate a lot of frequencies. But if you want to use the audio channels at 60KHz there is a little problem. There is a brick wall filter in the audio channel set at about 25 KHz. 
>Now I could set up the audio to output 15 KHz I and Q and mix it (quadrature mixer) with 45 KHz X 4 (precision source)  to get 60 KHz. And then filter it to get the 60 KHz. Which requires some op amps. And filters. A precision 45 KHz source. A gray code counter (divide by 4).  And stuff. 
>Easier to work at DC (my "audio" signal) and mix that up to 60 KHz directly. Besides. I do like designing and building hardware.  Engineering is the art of making what you want from what you can get at a profit. 
>I like Polywell Fusion.

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