What Use Is An F-call?

What use is an F-call? If you've ever sat at home wanting to listen to HF but you're radio is out of commission, worse still, you haven't yet got a radio, or your antenna is a project in progress, I stumbled on a way to have your cake and eat it too. I was hunting for examples of a pile-up and I'd found in the past radios that had been hooked up to the Internet that you could tune and listen to. Today I stumbled across something of a different magnitude altogether. Something called Software Defined Radio on the Web, or websdr. A group of amateurs at the Technical University of Twente put up the worlds first websdr in 2007. It was conceived in an attempt to connect the 25m radio telescope in Dwingeloo to the world, for radio amateurs doing Earth Moon Earth or EME contacts, it snowballed from there. So, now you can go to websdr.org, pick from a list of 40 receivers around the planet and listen to what ever frequency is within the station's range. The Twente receiver does 0 to 29MHz, there are UHF, VHF and G