  What would SETI Beacon transmitters be like if built by civilizations with a
variety of motivations, but who cared about cost? We studied in a companion
paper how, for fixed power density in the far field, we could build a
cost-optimum interstellar Beacon system. Here we consider, if someone like us
were to produce a Beacon, how should we look for it? High-power transmitters
might be built for wide variety of motives other than twoway communication;
Beacons built to be seen over thousands of light years are such. Altruistic
Beacon builders will have to contend with other altruistic causes, just as
humans do, so may select for economy of effort. Cost, spectral lines near 1 GHz
and interstellar scintillation favor radiating frequencies substantially above
the classic water hole. Therefore the transmission strategy for a distant,
cost-conscious Beacon will be a rapid scan of the galactic plane, to cover the
angular space. Such pulses will be infrequent events for the receiver. Such
Beacons built by distant advanced, wealthy societies will have very different
characteristics from what SETI researchers seek. Future searches should pay
special attention to areas along the galactic disk where SETI searches have
seen coherent signals that have not recurred on the limited listening time
intervals we have used. We will need to wait for recurring events that may
arrive in intermittent bursts. Several new SETI search strategies emerge from
these ideas. We propose a new test for SETI Beacons, based on the Life Plane
hypotheses.
