![germanium transistor germanium transistor](https://www.donberg.ie/pics/a/ac_126-7.jpg)
Unfortunately, the cover had lost all other information. I just replaced them with two BC327, and had to fiddle a bit with biasing, and the audio amplifier worked just fine! The third attemp was trying to repair the audio amplifier of a Siera vintage transistor radio. I just replaced them with two BC327, and had to fiddle a bit with biasing, and the audio amplifier worked just fine The third attemp was trying to repair the audio amplifier of a Siera vintage transistor radio. The two output PNP Germanium transistors (MP41)were also damaged. The two output PNP Germanium transistors (MP41)were also damaged. I had another vintage russian VEF 204 radio. I had to add some cooling stuff and luckily there was a quiesent current adjustment trimmer.
![germanium transistor germanium transistor](http://www.rainbowguitars.com/imagesproduct/or/orcali76gp-xl.jpg)
So I replaced them with BC327 for the AC142, and BC337 for the AC141. These are hard to get and I needed to get the radio working for somebody who didn't mind modifications, though I prefer vintage repair. In the USA, there are larger JEDEC standard cases (TO5 box) or smaller.
GERMANIUM TRANSISTOR SERIES
This concerns European series like ACs, industrial series ACYs, ASYs, ASZs, the british NKTs and the japanese 2SAs. I got a Siemens Club RK 231 vintage radio which had two dead audio output transistors AC141/ AC142. The TO1 standard was the first all-metal case used for germanium transistors when the black glass models were abandoned around 1964. If you ever had a vintage gear where you needed to get it to work but needed a replacement for Germanium transistors especially in audio circuits and you wondered if simply replacing with Silicon PNP transistors would work (with some tweaking and minor adjustments), the answer is yes.