Skip navigation
The other day, I was sorting through some old boxes and found a small bag of old transistors. There were two types, both of them PNP devices. One kind was an OC204 part, made by the old British company Mullard, the other a 2S3220 device made by Texas Instruments. I presume they date from the 1960s.         I wondered if they still worked and what their characteristics would be like compared to a modern device so I built up this circuit of a simple common-emitter amp ...