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14 Results for "fl2k"

  • FL2K Breakout

  • I threw together a quick breakout for the fl2k dongle so I can hook it up with all the connectorized microwave junk I've accumulated over the years from ebay.  There are min-loss pads on there for converting the 75-ohm output of the VGA channels to 50-ohms. ...
  • osmo-fl2k FTW!

  • I read about the osmo-fl2k program on the blog last week, and ordered one of the USB-VGA dongles from ebay immediately.  Within a few minutes of opening the package I had it spewing RF all over the bands (which is awesome and terrible at the same time). ...
  • fl2k rates through different ports

  • I used the fl2k_test program to check the sample rate I could get through various USB interfaces. First, through a motherboard USB3.0 connector: $ fl2k_test -s 162e6 Reporting PPM error measurement every 10 seconds... Press ^C after a few minutes. real...
  • Updated Breakout PCB (again!)

  • I modified the breakout PCB to include the +5V line, which I had overlooked before.  The FL2k dongles, at least the ones I have, do supply 5V on this line.  The latest design is in the GitHub repo, and the PCB is shared on OSH Park.I think this is the...
  • FL2k Experiments

  • This project is going to happen in the build logs: I'm basically treating this as a blog for ongoing experiments with the FL2k dongles.  This is a spin-off from #AM Band Voice Frequency Marker where I initially used this device to implement a project...
  • Interpolating with transmission line?

  • So, I started playing around with transmission line models for generating short sampling pulses, and it occurred to me that you could use a transmission line to interpolate between DAC samples.  It's kind of like doubling the sample rate just using a...
  • AM Band Voice Frequency Marker

  • The idea is simple: generate an entire broadcast band of stations at once. The first prototype (software-only) makes each station announce its own frequency in a synthesized voice. This is convenient for aligning and testing antique or simple radios,...
  • DAC Rolloff Compensation

  • As mentioned in the last log, the DAC on the FL2K VGA chipset introduces a frequency roll-off due to the first-order hold.  This roll-off is sinc-shaped, with the first zero at the sampling frequency.  As a result, an output at the Nyquist frequency...
  • DAC Impulse Responses

  • I wanted to copy these figures from the Maxim application note, but they're copyrighted and whatnot, so I wrote some quick python to calculate Fourier transforms for piecewise-constant functions and drew my own.  I would have paid good money for access...