"Louis Scheffer" <lou@cadence.com> wrote in message
news:4095e404$1@news.cadence.com...

Andrew Nowicki <andrew@nospam.com> writes:

Making a narrow, high intensity microwave beam does not
make sense because nobody knows where and when to aim
the beam.

Sure they do.  As a first guess, cover the planetary zones
of the nearest million stars or so, with beams that are on
all the time  [Think of the beams as looking like a pincushion].
Modern phased array transmitters can generate this
number of beams, and keep them focused on the stars,
with little problem.  And this is roughly the number of stars
for which we have adequate proper motion and distance measurements.
(You need both since the star will be in a different place when the
beam gets there.)

This is something we can do with existing technology for about
$200M, for a beam bright enough that we ourselves can detect it.
And this cost will come down further as a consequence of Moore's
law.

    Lou Scheffer

How did you get to just $200M for a system which cover 1M stars;
semi-continuously ?
How much power do you need for the transmitters ? Which cost/W do you use ?
And how large is the antenna that you need ?
No matter how I try, I cannot get this cost number to below billions of
dollars. Per year!

Either way, doesn't your cost go down if you increase your frequency,
and start pulsing rather than transmitting contiuously ?
What if you go to infrared or higher transmitters ? Wouldn't cost go down
many orders of
magnitude (Because you can make ns pulses and 'antenna' size reduces to a
small telescope...

It is more likely to find a beacon signal at the frequency, bandwidth, pulse
rate and pulse width which is most cost-effective for ET to produce and
detectable for us...

Did anyone make a formula for this already ?

 Rob