Russian GE transistors for dummies

[rnfr]

I have a number of designs utilizing these transistors on my blog page. apocalypsesudio@blogspot.com As well as whatever I could find pertaining to them that I found relevant. it was fun to dig into these devices back when they were cheap and everyone was scared to buy them.  now that the cat is out of the bag the prices have gone way up. I wouldn't be too scared of low gain readings. often times they sound great regardless.

[diy-tubes]

Looked your projects, very intetresting! GT313 are hi freq and for switching, can be hissy...
I'll try to publish real measurements (averages) of types I've got, and and compare with datasheet params.

[Atodovax]

DCA75 measures transistors with higher Ic (DCA75 Ic=5mA and DCA55 Ic=2.5mA) it gives a bit higher measurements. .DCA75 is good for simulating "real" conditions (within it's limits of 12v etc).

In terms of the Ic used in the HFE and leakage measurement what are the meters that are closer to the "real" conditions in Fuzz pedals, the DCA55 and Chinese at Ic=2.5mA or the DCA75(without using curve tracing) at Ic=5mA ?

thanks

I would like to repost this to see if anyone has an aqwnser to this. What specific IB or VCE should i take in count to simulate a FUzzFace circuit for Q1 and Q2? Because HFEs will vary a lot depending on those parameters on the same transistor

[italianguy63]

I did this work several years ago... I am just going to leave it here as someone may be able to use it.  I just happened upon it today in a folder.

MC

[ilcaccillo]

I did this work several years ago... I am just going to leave it here as someone may be able to use it.  I just happened upon it today in a folder.

MC

thank you so much for that table, quite usefull

[bluebunny]

I did this work several years ago...

Saved.  Thanks, Mark.

[digi2t]

I did this work several years ago... I am just going to leave it here as someone may be able to use it.  I just happened upon it today in a folder.

MC

GT404's (NPN) are missing from the list. I have a bunch, would you like me to test a batch?

[italianguy63]

Sure.  I can add it.

I just put in whatever assortment I had my hands on!  I just found that the advertised Hfe and real Hfe had big disparity in Russian trannies.

MC

[thermionix]

I just found that the advertised Hfe and real Hfe had big disparity in Russian trannies.

Trudat.  I bought a dozen or so MP21As because the supposed hFE range suggested they'd be Fuzz Face candidates.  In reality they were right where your measured hFEs say, with several below the "minimum" 50.  Quite dark sounding too, from various breadboard experiments, I haven't used any of them in a build.

[Rob Strand]

I did this work several years ago... I am just going to leave it here as someone may be able to use it.  I just happened upon it today in a folder.

Thanks for sharing that.  I'm not buying any but it's cool to have a look.

[Finom1]

Here is my list (name, original name, hfe according to datasheet)
Russian letters (as it goes in Russian alphabet):
А=A
Б=B
B=V
Г=G
Д=D
Е=E
И=i (I)
Ж=J (ZH)
Л=L

Etymology of names: russian letter П (english P) meant transistor (полупроводник), it's early tradition from 60-s, next - МП (english: MP), modernized transistor, and ГТ (GT) and 1T (1T) germanium transistor (tradition of naming based on transistor material).
1T (not IT!) is a kind of grade (military grade, slected etc). Sometimes even usual ge transistors (П, МП, ГТ) have a rombus marking - OTK marking or military grade, selected version.
Next appears silicon transistors - their names starts with KT (english KT) and 2T (graded version, military etc, in russian tradition - "5" ("military") acceptance).
Example of KT transistor is famous sub for 2N5088: russian KT3102E with hfe 400-1000 used in russian BigMuff's.
Numbers after letter - number of design and specifications.

GT series (ГТ)
Many of them (not all) have 1T version, wich is the same but selected, graded version, sometimes even with mentioned in datasheet higher Hfe)

• GT108V (ГТ108В) - hfe 60-130
  GT108G (ГТ108Г) - hfe 110-250
  GT109E (ГТ109Е) - hfe 50-100
  GT109G (ГТ109Г) - hfe 50-100
  GT109V (ГТ109В) - hfe 50-100
  GT115V (ГТ115В) - hfe 60-150
  GT115G (ГТ115Г) - hfe 60-150
  GT124B (ГТ124Б) - hfe 71-162
  GT124V (ГТ124В) - hfe 120-200
  GT308B (ГТ308Б) - hfe 50-120
  GT308V (ГТ308В) - hfe 80-150
  GT308G (ГТ308Г) - hfe 90-200
  GT309B (ГТ309Б) - hfe 60-180
  GT310G (ГТ310Г) - hfe 60-120
  GT310E (ГТ310E) - hfe 60-120
  GT311D (ГТ311Д) - hfe 60-180
  GT311i (ГТ311И) - hfe 100-300
  GT311k (ГТ311K) - hfe 60-180
  GT311L (ГТ311л) - hfe 150-300
  GT402B (ГТ402Б) - hfe 60-150
  GT402G (ГТ402Г) - hfe 60-150
  GT402E (ГТ402E) - hfe 60-150
  GT402i (ГТ402И) - hfe 60-150
  GT403B (ГТ402Б) - hfe 50-150
  GT403G (ГТ402Г) - hfe 50-150
  GT403D (ГТ402Д) - hfe 50-150
  GT404B (ГТ404Б) - hfe 60-150
  GT404G (ГТ404Г) - hfe 60-150
  GT404E (ГТ404Е) - hfe 60-150

P series (П) seems to be old series.
Low noise GE transistors: П27, П27А, П27Б, П28 suitable for first input stage.

• P27 (П27) - hfe 20-90
  P27A (П27А) - hfe 20-60
  P27B (П27Б) - hfe 42-126
  P28 (П28) - hfe 33-100
  P307B (П307Б) - hfe 50-150
  P307V (П307В) - hfe 50-150
  P414A (П414А) - hfe 60-120
  P414B (П414Б) - hfe 100-200
  P415A (П415А) - hfe 60-120
  P415B (П415Б) - hfe 100-200
  P416A (П416А) - hfe 60-125
  P416B (П416Б) - hfe 90-200

MP series (МП)
Low noise GE transistors: МП13Б, МП39Б  suitable for first input stage.
General usage, low frequency - МП21, МП40, МП41, МП42

• MP21A (МП21А) - hfe 50-150
  MP25B (МП21Б) - hfe 30-80
  MP39B (МП21Б) - hfe 20-60
  MP42B (МП42Б) - hfe 45-100
  MP15A (МП15А) - hfe 50-100
  MP16B (МП16Б) - hfe 45-100

The letters are given to distinguish them by Hfe, max collector-emitter voltage (like ГТ402Б (25V) and ГТ402И (40v)) etc
Many of them hard to find even in Russia (like popular ГТ402И (GT402i) which is good choice for Fuzz Factory clones).
Some of them have сomplementary types: ГТ402 (pnp) and ГТ404 (npn).

PS: Feel free to fix my mistakes, and add notes.

Thank you!!!

[Finom1]

Excellent resource; http://transistor-spravochnik.ru/

Don't let all the Cyrillic scare you. Just use the search box in the upper left, and use Latin characters. Or use a translator.

Thank you!!!

[ilcaccillo]

In terms of the Ic used in the HFE and leakage measurement what are the meters that are closer to the "real" conditions in Fuzz pedals, the DCA55 and Chinese at Ic=2.5mA or the DCA75(without using curve tracing) at Ic=5mA ?

thanks

I would like to repost this to see if anyone has an aqwnser to this. What specific IB or VCE should i take in count to simulate a FUzzFace circuit for Q1 and Q2? Because HFEs will vary a lot depending on those parameters on the same transistor

Hi fellow members,
anyone wants to chime in and help with our doubt?

Thank you so much

[sinthmart]

Finally, I found this useful topic of selection of germanium transistors.
I'll read it for now, but I'll ask how to find out what firmware is in my M328 transistor tester? To understand how accurately it displays the gain of germanium transistors.
By the way, my friend, an electronics specialist, also said that the well-known main scheme for selecting germanium transistors is dangerous for transistors and can ruin them, as is written here.
I have this one - -

[amptramp]

A number of old tube testers came out in the era of germanium transistors like my EICO 667 with the schematic shown here:

https://bama.edebris.com/download/eico/667/Eico_667_Schematic_and_mods.pdf

bama is Boat Anchor Manual Archive with boat anchor referring to ham radio receivers which tend to be heavy items.  edebris is a mirror site for bama that became the only way to access bama stuff.  They have a huge array of test equipment manuals and schematics as well.

If you find one of these tube testers with the transistor option, you might have what you want.  Note that under EICO 667, you have the instruction manual for using the transistor test function.  If you are working with guitar amps, you will need a tube tester of some sort, so you might already have what you need.