You can certainly point your dish to a DirectV satellite with an FTA receiver, but cannot tune the satellite stream. It is a proprietory stream and can't be decoded by a typical FTA DBS box.
Google on DSS satellite, and you'll find more info.
A FTA receiver will not see anything on the direct 101 satellite. An old direct receiver will see directs tv guide and channel 100 if the card is in it. Great for a free tv guide thats about it. Ch 100 is a list of channel numbers.
directv uses dss, most fta uses dvb. slighty different standards, but different enough that it wont work. like Digicipher II and dvb, close but not the same.