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hello jtn191,


well, GT308B should be like this, when measured at 1 mA. It's better to order GT308V then. Only i can question, Ikbr looks way too high, it typically not exceeds several microAmperes. At what voltage did you measure and can you show schematic?

Windjview http://sourceforge.net/projects/windjview/ is worth use, in my opinion. Datasheet is in russian, but there is a way to pull information you need  - transistor list at the end with page numbers, you go to that page, and when you see anything like range "50 – 100" - it's h21e (at measuring current specified somewhere near).

Hello,

i could comment, these germanium transistors have letter, and it is a grade just like described in datasheet. For early types very often grade is for combination of U cb max and h21e, but not limited to.

so if you want to get best transisitors you need to choose right letters, they are often same price, because seller doesn't care. Letters are cyrillic, so do not confuse cyr. Б (latin B) and cyr. В (latin V)

Datasheet can be found here. http://www.volt-220.com/images/book/transistors.djvu

GT308V (ГТ308В) are maybe better of classical HF germanium (П403А and П416Б are almost as good), and ГТ402/404Б,Г(B,G) are maybe better of classical AF germanium (МП11A,15A,38A,41A are good too). But these GT402/404 not only have twice higher dissipation power (comparing to all P/MP), but have very good h21e linearity (against varying current).

But again letters are important, for example one letter might have h21e 100-200, next letter with h21e 50-100, next 25-50. There is absolutely no rules in letters, just consult the datasheet.

Industry/Military grades are marked as 1Т instead of ГТ, and special grades for aerospace have OC in the end. Not all items have its special grade twin. Those special grades are mainly for wider temperature range, they do not show better h21e (but can show less reverse current at room temperature, and of course tremendous reliabilty).

Yes, and these GT 108, 109, 309, 310 have small cases and small power (109 and 310 are tiny and 20 milliWatt), so if you think you need this, you can use it too.