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I'm interested in Software Defined Radio. I have basically no experience in any of the electrical engineering or math topics involved, but I'm reading...

Rather than trying to deal with the hardware aspect of the antenna and the ADC, I imagine it'd be fun enough (and cheaper) to play with some pre-recorded (or even live!) sample streams of the AM band.

From what I've learned so far, it seems to me that the AM format would be the easiest to decipher - a narrow bandpass/windowing function over the entire spectrum to get any target frequency, then a short running average transform(?) to get another sample/sample amplitude to get the audio signal.

For the full North American AM band, seems to me that the uncompressed stream would be:

1606.5 kilobytes x 2 (twice the frequency for samples) x 2 (16-bit samples) = 6.28 megabytes per second

It's probably clear that I'd be wasting my money on the hardware at this point... Any sources of AM band out there? Or other better ideas for hands-on learning?

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Jason Kleban
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  • Sounds like a fun project, but I'm not aware of any samples of the AM broadcast band that you can download - it would take some fairly expensive hardware to do this, but it's not unfeasible, and someone somewhere may have done it. Good luck, anyway. – Paul R Jun 25 '10 at 18:38
  • PERSEUS SDR is about $1100. I think this will do it, but not sure. I've also seen "SDR kits/Vector Network Analyzer" (http://www.sdr-kits.net/) for what look like $85 - a big difference, but why?? The $85 thing SOUNDS right. 1 kHz - 500 mHz. If anybody has this equipment, it'd be sweet if they could host samples somewhere! – Jason Kleban Jun 25 '10 at 20:51
  • And advise on the choice of equipment for this type of application. – Jason Kleban Jun 25 '10 at 20:51

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You should talk to the GNU Radio folks, or at least look at their code. They're doing software radio development and must have samples for doing unit testing.

Max Shron
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