You can make your own magnetic pulser at home. The first item needed to build a magnetic pulser is a full length video cassette to break apart.
The video tape is broken in order to retrieve the spool inside. Other items needed to build a magnetic pulser include a 2-inch-long 3/16 bolt, 2 washers, a nut, set of epoxy glue and a 1/4-inch-wide wood spatula. Also required are 1/1/2 pounds of #14 gauge copper wire, and two pieces of plywood that are at least as big as the spool taken from the video tape. If epoxy glue is not available, silicone caulking can be used as a substitute.