In article <411eff9e$0$294$edfadb0f@dread16.news.tele.dk>,
Martin Andersen <martin@al-data.dk> wrote:

As far as I know, SETI are not looking for transmissions leaked from an

Usual problem: SETI is a process, not an organisation.

to be detected. Instead, SETI could observe signals sent deliberately

Phoenix would claim to be able to detect leaked TV carriers, given a long
enough observation time (which they can't currently afford).

towards earth, with frequency near the neutral hydrogen line at 1420 Mhz.

Berkeley (who run S@H) observe at optical frequencies, and their 
SERENDIP project covers 100MHz, so differs from the hydrogen microfine
line by 5%.  The SETI Institute's microwave projects cover even wider
frequency ranges.

The reason SETI hasn't yet detected an artificial signal may be
the low number of stars observed until now, approx. 1000 stars have

Berkeley's SERENDIP and S@H projects will have covered over 10% of the
stars in the visible universe.  The SETI Institute's Phoenix project
may be limited to about 1,000 but they have a much wider frequency
coverage.  S@H/SERENDIP are not targetted so consider all stars in the
field of view.