AO-27 is a mode J FM bird. UO-14 was launched as a digital workhorse. It managed to carry digital traffic half way around the world for medical staff working in communication challenged third world countries. The torch, and duties were passed to UO-22. Since all these birds are low earth orbit satellites, most passes will be between 6 and 18 minutes in duration.
Timing is critical in working any amateur satellite.
Since these birds are all considered weak signal, you must know when the satellite will pass over your location, and where in the sky to point your antenna. Be sure to download the latest Keplerian coordinates if you download a tracking program. Each prediction program needs these coordinates to determine where the satellites are, and to help you determine when the satellite will be over your horizon. Be aware, that as of the time this article was written, this site is using stale Keplerian coordinates, and might not give absolutely correct positions for the satellites. They might be off by close to a minute.