[time-nuts] Sidereal time

[Neville Michie]

I have been trying to set up a clock on sidereal time. 
My only source of a time calculator is  tycho.usno.navy.mil,
but this seems to be off the air for the last week or more.
Is there any other source of sidereal time?
The basic method needs a current almanac and I can not even find a source of one of those.
How you would find ST to a microsecond is not obvious. How do radio astronomers do it?
cheers, 
Neville Michie