You must have been trying to access Frank's Electron Tube Pages. I tried to bring it up yesterday but got an Error 404 message.
Try the main Netherlands page. The tube data resides on several mirror sites in several countries and they are identical, except for the Poland site which additionally has been equipped with a tube search. The main website is the one in the Netherlands, his home country: http://www.tubedata.info/
He recommends that if you make a link to the tube data website, to use that url.About this Website
I clicked on the Australian link and everything was there. The U.S. link has gone dead for some reason.
One thing I like about this site is that it includes data sheets from several sources, e.g. RCA, Sylvania, General Electric, Tung-Sol, etc. Sometimes certain ones contain information that the others don't have, so when I am looking for data for a tube, I check them all.
I find it extremely helpful to print out the characteristics curves for the tubes, and use them to plot out operating parameters not given in the data sheets, for example, to calculate the optimum plate load impedance for a transformer-coupled voltage amplifier stage. I can draw all the lines I want on the chart, without damaging the ones in my tube data handbooks, and printing from this site is much easier than scanning and printing from my book collection, or going somewhere to use a photocopier.