2. Has anyone tried the dual band COMPACTenna for satellite work? There is some mention of it on their website and in the review this month in QST. I like the idea of a more omnidirectional antenna that I can just put up on the roof and forget about it and not worry about running up there with the Elk and the HT whenever I want to make contact.
Since Patrick took 1 & 3, lemme get this one.
Omni & more power - You are going to make up for the uplink that way, but not the downlink. The gain on a directional antenna is as important for receiving, if not moreso, than it is for transmitting.
up on the roof - Coax loss... Even with good coax, you will likely see a lot more feedline loss on UHF than you will with a few feet to a handheld antenna. So you would likely have to install a mast mount preamp. And depending on the length of the run, that might be the case even if it was a directional antenna with a rotor.
So... what about a different antenna? If you can acquire a TV rotor, you can likely build or acquire a small directional antenna (don't want a huge one; would be too much weight AND gain) say 3 like an Arrow, Elk or similar and then aim the antenna about 15-20 degrees above the horizon. Most LEO satellites spend the majority of their time below 40 degrees relative to any one point. So in other words... when the satellite goes overhead, it shoots by relatively quickly AND it's overhead... it's going to be louder than at the horizon! A number of sat ops (including me) have tried something like this and it worked pretty well. You do not get 100 percent of the pass every time (as it fades some when overhead), but usually you are busy rotating the antenna around to the 'other side' anyway.
That said... even with a directional antenna, you may still need a preamp on UHF downlink birds. With my trial setup like this (before going to full AZ-EL yagis) I had 3 elements on VHF, 5 on UHF with ~50-60 feet of cheap RG-213 coax and would work a number of birds... SO-50 was not one of them. I could actually hear SO-50 easier with a small handmade 3 element yagi mounted right on an HT while sitting in my chair in the shack than I could over the outside antenna. Without a preamp and being pointed exactly at it, just didn't work well enough.
So... hopefully that answers a few questions or at least brings up a few more.

A lot of hams new to satellites think 'Oh, I'll put up outside antennas, will be so much easier,' but there is a lot more to consider than most realize. I did start out that way and went to handheld roving later... and now that I have moved to a new QTH with lots of trees, occasional roving is about it for me. I do have up a pair of omni antennas on the roof with about 40 feet of coax, but I am VERY limited as to what I can hear. If it's not right overhead, I'm not hearing much.
As always, your mileage may vary... but I don't think a gallon will get you too much further than everyone else.

73 & welcome to the addiction that is satellites, Kevin N4UFO
P.S. While I may only have been a ham for 45 years at this point, I got back into satellites (I used to work RS-12/13 on HF in the late 90s) when my wife bought me an HT that cost 50 bucks for my 50th birthday to try out SO-50. One contact and you could hear the line being pulled out of the reel.
