For decades I have sought early transistors and until recently I had never come across any from China. However, now I have found a Google book that describes how the "13th Research Institute" was founded in 1956 and had produced a Chinese germanium transistor in 1959.

I show some Chinese transistors below, and they do seem to bear logos, but I have no means of identifying the manufacturers.

If you can help, or just know more about the early history of the Chinese semiconductor industry, please


Chinese germanium transistors seem to use a number of standard series (however, there are probably interesting early anomalous types of which I am unaware):

If you can tell me more, especially about early types, please


3AD1 transistor

The oldest Chinese transistor types that I possess are these unpainted 3AD1 and 3AD2, apparently dated 70 02 and 66 X respectively. The part numbers suggest that they are early types, but I have no confirmation in the form of a data sheet or book. I don't know what the logos signify. Radiomuseum states that these are PNP germanium alloy transistors intended as an AF power amplifier / switch, but their reference is just listed as "chin. datasheet ".

If you can provide information about Chinese germanium transistors or diodes, or know where I can obtain more, please

I do have enough 3AD2 that I can trade some for other interesting types.

3AD54C transistor

I also have some of these 3AD54CJ: a high-power PNP type in quite a primitive can. I don't know the significance of the handwritten J at the end of the rest of the part number. The manufacturer's logo is a quite complex geometrical shape, again if you can tell me who that is, please The code 84.IV suggests that this is not a particularly old example.


3AX1 transistor

The next Chinese transistor type that I possess is this small black tophat 3AX1. This part number suggests that it is an early type, but I have no confirmation. There seems to be a strange logo in the top half, and no date (or other) code. Radiomuseum states that these are PNP germanium alloy transistors intended as an AF amplifier and gives a reference of the Steidle book "Transistoren Taschen Tabelle" from 1981.

If you can provide information about Chinese germanium transistors or diodes, or know where I can obtain more, please

3AX2 transistor

I also possess these 3AX2. The manufacturer's logo is a five-pointed star: I don't know who that is. The case is a normal-looking TO-1A, and they are coded 81 IX. If that is a date code, it is a lot later than the time at which silicon replaced germanium in the West, although it is quite possible that China lagged in this respect. Again Radiomuseum states that these are PNP germanium alloy transistors intended as an AF amplifier and gives the 1981 Steidle book as reference.

If you can provide information about Chinese germanium transistors or diodes, or know where I can obtain more, please

3AX55C transistor

I also have some of these 3AX55C: a low-power PNP AF type like the above. However this has a larger cylindrical can, and strangely, one of its leads is noticeably thicker than the other two. The manufacturer's logo looks like the letter A in a letter G. if you can tell me who that is, please The code 85.43 suggests that this is surprisingly modern for a germanium device.


wanted

I do not have any early transistors in the other series: 3AG,3AK or 3BG. If you can tell me where to get some, please


2AP7J diodes

As for Chinese germanium diodes, I have seen the prefixes 2AP and 2AK for glass miniature point-contact diodes, 2AV for cartridge-type point-contact microwave diodes, and 2AU for photodiodes. I don't know about germanium rectifier diodes, nor any kind of silicon diode. These 2AP7J are the only Chinese diodes I possess; radiomuseum states that type 2AP7 is a germanium point-contact general-purpose type. I don't know what the suffix J signifies, nor whether the Chinese symbol is an alphabetic character or a logo.

If you can tell me more, especially about early types, please