alt Hacker NewsNice, I ran across that a month or two ago and it was great. I got to the OC71 germanium transistor and found out they're obsolete.
Nice, I ran across that a month or two ago and it was great. I got to the OC71 germanium transistor and found out they're obsolete.
Silicon PNP transistors should work in those circuits.
It's also trivial to reverse all the polarities in the circuits and switch to NPN. Use a positive supply voltage rather than negative, flip the rectifier diode around as well as all the electrolytic caps.