[Discuss-gnuradio] Low-Cost USB Capture Hardware

[Colin O'Flynn]

Hello,

 

I wondered what interest there is in HW which can perform capture, but is more limited than the USPR2 type devices. For a different project I made a high-speed ADC interface, which runs over USB. It’s one channel, 100 MSPS.

 

I won’t attach images so you can see details at http://www.newae.com/tiki-index.php?page=ProjectOpenADC .

 

It does not do real-time streaming, but captures a short number of samples (e.g.: that board has LPDDR memory which can fit ~32M samples), and downloads them slowly over USB.

 

The site has an example of measuring the roll-off due to front-end – note this graph alone is fairly misleading, as the SFDR limit is a lot lower (~300 MHz analog BW). If you do filtering after digitizing & know where the spurs are you can get a pretty high analog BW… have to upload full details of the spurs. There is also an adjustable amplifier which lets you crank up to ~50dB of gain on any incoming signals (you can go higher but noise becomes an issue, need shielding) but with a much smaller analog BW.

 

If there was interest I could look into getting a batch of PCBs made. The ADC + Amp chip are the main expense (~$15 each), I would imagine assembled cost would be in the $60-$100 range. It’s all open hardware so I’m not exactly getting rich here J

 

Regards,

 

  -Colin