Eric Foster Minipulse Schematic with pictures for your viewing

[adam(Va)]

My attempt to reverse engineer an Eric Foster Minipulse. There maybe some errors, I no longer have access to this detector so what you see is what you get. Please don't ask me to explain how this thing works, I only traced it out. Made this using some of my hand written notes. Enjoy!

Coil is = 330 uh
Battery is = 9v transistor

[kt315]

well done, Adam! thank you for the sharing of the info.

all the best

[mollax]

If we look at the pcb
such a scheme should be

[DavidB]

What year was this detector made? I remember using the 709 in the early 70's when I was in high school but have not seen one used in quite a while.