4 Pcs TO-220 5 Pin Burn-In Socket Pitch 2.54MM TO5P Aging Test Socket 5 Poles Though Holes PCB Straight Diode Transistor Flange - AliExpress
For the transistor in the figure, it is given as | Chegg.com
Bipolar transistor BJT - infootec.net
The Bell System technical journal . -X—X- -AW- TWO 180° SECTIONS J^ -o-o-. JW Fig. 13 —• Non-inductive active phase sections. THE TRANSISTOR AS A NETWORK ELEMENT 347 i(les ii total