Another note on DIY building this tester read the notes lalo na yung arrangement ng test terminal.
It should be number if horizontally place to be PIN 2-3-1 from left to right. Or 2-3-1 from top to bottom where 2 is at the top mid (3) bottom (1).
Reason. When I place a 5200 and 1943 where PIN arrangement of 3-2-1 vertically top(3),mid(2) and bottom(1)
Placing lead terminal of transistor PIN(1) and PIN(3) to Tester PIN(1) and PIN(2) and the middle transistor lead to Tester PIN(3). Read BEC that where supposed to read BCE(the correct terminal marking. Same thing if you place it in between Tester PIN(2) and PIN(3) and the mid to PIN(1). Error reading.