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Good Grief… Not again!

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Max The Magnificent
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re: Good Grief… Not again!
Max The Magnificent   2/2/2012 1:46:15 PM
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I just tuned my old AM radio to the static between stations and... ...Elvis says (a) stop talking about him or he will have to come round to your house and have words with you and (b) what's an FPGA?

ost0
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re: Good Grief… Not again!
ost0   2/2/2012 8:46:50 AM
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Hmm.. I would think this is a matter of picking up the "magic" that makes theories not work. How about a "skew detector" of apparently equally delayed signals? Maybe source a pair of signals from a common high frequency (variable?) PLL (could be FPGA internal too), send both through some apparently symmetric paths, and sample one of them on the other domain at an invalid setup/hold edge, filter it with some magic filter, PWM it to a speaker, and maybe Elvis will speak to you? (any volunteers wanna try?)

Max The Magnificent
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re: Good Grief… Not again!
Max The Magnificent   2/1/2012 10:41:54 PM
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That sounds great -- I can't wait to see it when you finish it -- make one for me too :-)

Rick_Hille
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re: Good Grief… Not again!
Rick_Hille   2/1/2012 10:08:27 PM
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A small micro with an ADC that can sample at audio freq could be employed; the recorder output, which is the signal point to run into the ADC input, would need DC bias to about mid-point of the ADC input range. If the ADC is fast enough and the uC has enough horsepower, you can implement a Nyquist low-pass filter as a digital algorithm. Or maybe, forget about filtering and let the above-Nyquist chirps and squeals produce interesting sounds, never before heard by human ears... Alternatively, you could run the recorder output into the Line input of a PC sound card, and use a tool like Audacity to examine and play with the waveforms. I'd add a couple paralleled A to K diodes on the recorder output to protect the PC input port. For the previously mentioned ADC approach, diode clamping of the recorder signal to the uC rails would be advisable too.

Max The Magnificent
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re: Good Grief… Not again!
Max The Magnificent   2/1/2012 9:21:45 PM
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I wonder if it would be possible to come up with a sort-of-digital equivalent of this circuit - -perhaps using a microcontroller or an FPGA -- pick up the signal in the analog domain but then immediately convert it to digital for processing... ...anyone want to try?

Max The Magnificent
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re: Good Grief… Not again!
Max The Magnificent   2/1/2012 9:20:14 PM
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That is a very good name for it. From what it says in the original construction project, I cannot wait to actually hear the sounds I'm supposed to here... If we do get it working (and I have every faith in David) I will create a YouTube video including the sounds so you can see (hear) what it's like...

Rick_Hille
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re: Good Grief… Not again!
Rick_Hille   2/1/2012 9:17:04 PM
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Clearly, the cardboard substrate is not nearly large enough :) From your description of what this box is supposed to do, I'd rename it from the rather pedestrian "Atmospherics Monitor", to "God's Theremin"

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