AO-27 is a LEO satellite, which means Low-Earth-Orbit.  Most locations in North America will get 3 daylight passes from the satellite each day. The longest of these would approach 15 minutes. AO-27 is only "on" during the daylight passes.  The Equipment section will discuss methods for determining the times and locations of the passes.      AO-27 (also known as "Eyesat") is actually a commercial satellite put into orbit by Interferometrics of Virginia. The amsat FM repeater "tags along" on this research satellite.      The repeater transmitter outputs between .6 and .8 watts, making the reception of the downlink the most challenging part of using the satellite. The receiver is very sensitive, and there are many true QRP users of the satellite. The recommendations are for up to 5 watts on a non-directional antenna and only 100 mw when using high gain directional satellite specific antennas.       Mobiles, both handheld and vehicle mounted, and fixed stations use AO-27. There are even repeater "gateways" which make it possible for any repeater user to work AO-27.