If I remember it correctly, Realtek made this board as something to market as capable of receiving public digital TV waves. It was widely manufactured, likely as part of the big U.S. digital switchover, so volume was high and costs accordingly low, saving passed on to the consumer in the form of cheap hardware. As far specs, using for "just" digital TV was like putting a Ferrari engine in a Prius. But it lay mostly dormant because the chip's API wasn't published except to the handful of vendors who likely paid millions for the spec.

But curiously sniffing around the simple device, in true hacker style, someone found traces of something far more awesome and dashed off the above email to a public mailing list. From there, the a community of software radio enthusiasts together reverse engineered enough of the API to make the extremely low cost (~$20) consumer hardware usable with open software such as the software defined radio (SDR) application Gnuradio. For a lot of the cooler applications of SDR you need two radios - one to transmit and another to receive - and previously the cheapest options were USRP brand radios from an outfit that did wonderful engineering but whose hardware was prohibitively priced for amateurs.