I recently decided to fool around with another hand made point contact transistor. As in my previous successful attempts, I used the germanium die from an old diode and two points made from phosphor bronze wire. This time I had access to binocular microscope and a proper curve tracer, which made things move along much more easily. The curves shown here were taken without forming the collector, so the gain is low, essentially 1. The base current step size is set at 2µA, and the vertical current display is set to 2µA per division
I tried dabbing some cyanoacrylate glue onto the transistor to hold everything in place before making attempts to form the collector, and while the transistor continued to function as shown at first, after it had hardened it no longer showed useful behavior. I still count this as a success, as it took much less time to get promising results during this attempt than previously. Unfortunately I did not try running the transistor with its attached phase-shift oscillator circuit before operation ceased.
