This part is a kind of semiconductor called BF964S.

Function of this product has N-Channel Dual Gate MOS-Fieldeffect Tetrode/ Depletion Mode.

Manufacturers : Vishay Telefunken

Image and pinout :

Some of the text within the PDF file :

BF964S Vishay Telefunken N–Channel Dual Gate MOS-Fieldeffect Tetrode, Depletion Mode Electrostatic sensitive device. Observe precautions for handling. Applications Input- and mixer stages especially VHF TV-tuners. Features D Integrated gate protection diodes D High cross modulation performance D Low noise figure 3 4 2 94 9307 96 12647 D High AGC-range D Low feedback capacitance D Low input capacitance G2 G1 D 1 BF964S Marking: BF964S Plastic case (TO 50) 1=Drain, 2=Source, 3=Gate 1, 4=Gate 2 12623 S Absolute Maximum Ratings Tamb = 25_C, unless otherwise specified Parameter Drain - source voltage Drain current Gate 1/Gate 2 - source peak current Total power dissipation Channel temperature Storage temperature range Test Conditions Type Symbol Value VDS 20 ID 30 ±IG1/G2SM 10 Ptot [ ... ]

BF964S PDF Datasheet Download