The downlink of EAGLE will be made some where between 5830 to 5850 MHz
and as far I know the exact frequency segment has been not yet decided but you need a downconverter specifically designed to receive the above band when it will be chosen. Now if your 2.4 GHz upconverter uses a 2 meter IF then you must use a 70 cm IF for your 5.8 GHz downconverter. A 70 cm IF allow you to get a better receiver image rejection on downlink while not to be IF to IF interfered using a 2 meters IF for the uplink.
Won't this (5830-5850) C Band downlink for Eagle be the same problem as S band? I changed all my cordless phones (4 of them) to the 5.8 ghz band so they would not crash my 2.4 ghz wireless network. Won't my 5.8 ghz phones interfere with hearing Eagle on the 5.8 ghz band? My Linksys 2.4 network did not bother my 2.4 ghz old phones but the old 2.4 ghz phones brought down my network. The phones are a lot more powerful then the network. I assume the same is the case for my new 5.8 ghz phones.
I guess for satelltes (Eagle anyway) I will just use U/V mode and keep my phones and network the way they are. I could have used S band down but i really doubt i will be able to use C band down (along with all my cordless phones on the same band).
Les W4SCO