In article <2eba5b2a.0412050440.58e6ea4@posting.google.com>,
myra@gsl.cz wrote:

I am sorry if I'm posting something that has been already discussed.

You did look at the FAQ??

Does human race broadcast some strong signals at the frequencies that
are scanned by SETI?

Yes.

                     If some extra-terrestrials had a project similar
to SETI, would they have a chance to find us?

If they had a project similar to project Phoenix, they might find us.
If they had a project similar to project SERENDIP, they might find us.
If their only project had equivalent coverage to the SETI@Home subset
of SERENDIP, they wouldn't find us.

Signals we generate are radar, particularly planetary radar, and at the
extreme limits of dectablity, analogue TV carriers.  There have also 
been token active SETI transmissions.

If not, why do we assume that they broadcast on such frequencies?

In addition, because those frequencies are amongst the most likely to
result in successful contact and they want to be found, for academic
reasons, or their civilisation is facing destruction.

Subject: Re: Do we broadcast in the water gap?

Note that this is not a good translation of water hole, as it doesn't
apply to SETI@Home.  The sense of water-hole for searches close to 
1.42GHz is that of a pool of drinking water where different animals
gather.  It is possible that it is not possible to translate water hole
into other languages and maintain this double meaning.

Your translation could apply to either of the other definitions,
although neither SERENDIP nor Phoenix match the intermediate definition
(between the Hydrogen hyperfine line and the hydroxyl lines near 1.6GHz).
The only real  definition that matches all of them (and I think Phoenix
actually extends below this) is the range between where galactic noise
becomes low and atmospheric water vapour noise becomes high, which covers
almost all commercially used frequencies from mobile phones upwards.