> David Woolley wrote:

In article <41B78817.2040805@sbcglobal.net>,
Alfred A. Aburto Jr. <aburto@sbcglobal.net> wrote:

David, you think seti@home doesn't have a chance because the bandwidth is too small? Just curious ...

Because it is listening in a frequency range that is internationally
reserved for receive only radio astronomy.  (This does have a benefit that
it means you don't get RFI from intentional, in band, signals.)

The "protected" band extends from 1400MHz to 1427MHz. I think it just means there are no powerful transmitters allowed in that band, but it is filled with RFI however from all kinds of electronic devices in most local areas (San Diego, ...). One needs to go to physically "remote" areas (they are disappearing)to attempt to be free of RFI ...

So we would not "hear" (detect) ourselves in that band at any large range (light-years away), lacking powerful transmitters there.

I wonder of ETI would adopt the same philosophy and not transmit in a band around 1420MHz for the same reason we don't!? Seems logical that they would not. For that reason the "water-hole" or "water-gap" may not be such a fruitful place to search after all! Wow!

The range is protected to cover Doppler and some cosmic red shifted hydrogen
line signals.