...equatorial clock drive or computer control on your altazimuth so your dish can track continuously and integrate on a spot on the celestial sphere

Yes I did think of that. I could never find one that worked right so I wrote it myself. It’s called the SETI Net Clock and does that Az/El to DEC/Ra conversion and all the other stuff. When I lock on a star it’s the guts of the clock that take over and keeps it locked. I can integrate for many hours on most points in my antennas look area (the horseshoe figure on the Sky Map).
The clock is one of the things for sale on SETI Net.

Will your equipment automatically reject any modulated signal?

No it doesn’t automatically reject modulation and *if* ET were to send CW (on/off) code very slowly I could see it. The problem is that if you integrate for long periods the modulation gets smoothed out and if you integrate for short periods then the signal goes down in the mud. So I assume that ET will send a pure modulation free signal. This type of signal cannot, to my understanding be created except purposefully so it works best for me and I hope for our ET friend.

…but have you considered also correcting for earth's motion around the sun as well? At 18+ miles per…

I considered it but some a quick calculation shows that even 18 MPS would make a very small Doppler shift at 1420 MHz and the equations would take a long time to run on my already over taxed computer. There are conjectures that ET would chirp his transmitter to correspond to the Galactic movement of our star around the center of the Milky Way as a way to positively identify the beacon as purposeful but that one is beyond me as well. I’ll leave that to the big guys at SETI@Home. All the corrections you mention would be great but depend on ultra small bins (0.1 Hz/Bin or so) where mine runs out of gas at about 1.4 Hz/Bin.

… Finally, have you tested your rig by attempting observations of natural radio emitters? …

It turns out that our sun (good old Sol) is very quite at 1420 MHz and I can’t see it at all with my narrow band receiver. Many people have made wide band receivers and use the sun to adjust there antennas but I never have.
As far as I can find out there are no natural signals that I can receive with my station the way it is. I have to us GPS signals and even they are a bit out of my band. My Horn runs out of bandwidth at about 1500 MHz and the GPS signals are a bit higher than that. I can see them but it does distort the side lobe curve of the antenna.

Regards……… Jim www.SETI.Net