The Trenton cutoff only sees one train per day west of the Schuylkill River - it's a steel train but I have no idea what its schedule is. Amtrak is in the process of rebuilding the Keystone Corridor (Amtrak owns it, cost for rebuilding is split 50/50 with the state of PA) and in Frazer, it's a new railroad from the ballast up. Fresh concrete ties, CWR, the works. They're working on the catenary to enable electric operation again, but for now expect to see Genesis diesels on the point of the Keystone trains (Phila.-Harrisburg) and on the one Pennsylvanian that runs through to/from Pittsburgh. Check
www.amtrak.com and use their schedule finder between PHL and LNC (Lancaster) to get an idea of when which train will zip by Frazer. To see if you'll catch any SEPTA Silverliners, check
www.septa.org, and follow the regional rail schedule links to the R5 Paoli/Downingtown PDF.