Want this question answered?
its a n channel jfet(field effect transistor) manufactured by Motorola
Some MOSFETs have a 4th terminal that is the chip substrate (which may or may not be connected to the case).However the BFW10 is a JFET and therefor has no chip substrate, instead the 4th terminal is the metal case which is used as a shield (this part is intended for VHF/UHF use and should be well shielded to prevent interference, crosstalk, and/or unintended feedback).
its a n channel jfet(field effect transistor) manufactured by Motorola