Showing posts from January, 2021

fl2k_noise generator

The  osmo-fl2k project  shows how to use an USB 3.0 VGA adapter as SDR transmitter.  Many thanks to Steve Markgraf. He presented it at OsmoDefCon 2018  . I made a  console tool named fl2k_noise that generates white noise in the full HF band. You can buy Fresco Logic 2000 based USB to VGA adapter in Aliexpress or Ebay for some 5-10$ price. See more info and the adapter scheme on The adapter was laying in my shack when I decided to test it as wide band (white) noise generator for HF band.  I selected an old VGA to VGA cable quite long and flexible and I cut it in the middle,  I cabled it as in the following scheme to adapt the 3 *75 Ohm input to the 50 Ohm output. The capacitors remove the VGA DC component and in case isolates the ANT bias tee of the receiver. The tentative code is in my repository  . It's a fork from