ARP 4002 Exponential Sub-Module The 4002 was an encapsulated PNP-based exponential current generator current sink). SCHEMATIC - (click on image to download full-sized version)
PARTS LIST Resistors 1/4 watt, 10%, carbon composite 10 K R4 33 K R5 1.5 Meg R2 2.2 Meg R3 Tempco Resistors 1/4 watt, 3%, +3500ppm 100 Ohm R1 Diodes 1N4148 CR1, CR2 Transistors TZ-81 * Q3, Q4 TZ-581 ** Q1, Q2 (matched pair)

* - TZ-81 alternate part was the 2N5249, also defunct. 2N3904 would be a modern equivalent.

** - TZ-581 alternate part was the 2N5367, also defunct. 2N3906 would be a modern equivalent.

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