Hi, Jordan. There are many good sources of information to help you answer your questions. The ARRL Microwave Handbook (not either of the project books) and the "Mode S Book" from AMSAT are good. If you are interested in P3D (only uplink S-band bird I'm aware of in the works) look at the "P3G to P3D", that I edited and that is available through AMSAT. You're right to be interested in atmospheric losses in the microwave region of the spectrum. It is a complicated function of humidity, temperature, pressure, etc. Don't worry about it much for satellite communication, however. As far as antennas, more gain is always good. Dishes seem to be favored over yagis above 1.2GHz due to something called capture area. And, for P3D, you better not put much power into a high-gain array and point it at the bird. Uplink signals that are TOO STRONG can serious degrade the operation of the satellite. An important point is that the higher the gain of the antenna, the more accurately you need to point the antenna at the satellite because gain and the angular width of its window are inversely related. Coax loss is what you're getting at with the questions about the converter at the antenna, vs. remote with a preamp alone at the antenna. All of these issues are covered in the three publications (collectively) above. You're moving into microwaves, now, and need to get up to speed on the differences between these freqs and HF. Best 73's --Paul Beckmann, email@example.com P.S If your interested in some interesting experiments to do with satellites, both ham and commercial, look at the RSGB Satellite Handbook, available through ARRL.