Thanks to a recent post by Ricardo Ribeiro, I learned about a new fado program on Internet radio, and it sounds great. The station is Rádio Sim (Radio Yes).
The station broadcasts fado every day between 22:00 and 24:00. They promise "the most important music taken from the history of fado, as well as the best new work of this distinctly Portuguese musical genre." Follow this link, then click on Ouvir Emissão.
Check them out!
And here are some other alternatives:
Rádio Amália: the pre-eminent station. 24 hours/day
RTP Fado: a relative newcomer with a wide range of programming, including live concerts. 24 hours/day.
Popular FM: Wednesdays, 21:00-23:00. You can always check out the homepage of the DJ, José Nobre.