Author Topic: Germanium Transistors! Help!  (Read 867 times)

Germanium Transistors! Help!
« on: November 23, 2021, 11:14:50 PM »
I am looking for Germanium Transistors for audio purposes. I need to be provided with NUMBERS and names of the transistors.
 
The most important parameters are : LOW Ube ( Ueb ) and the lowest voltage must be >= 30V, preferably, >= 40V.
 
When audio rating is not available, non audio is OK.
 
Complementary transistors are preferable, but, when not rated as such, NPN and PNP transistors with similar parameters are welcome.
 
Here are some of the desired specifications :
 
1. Germanium.
2. Typical, low, Germanium Ube ( 0.2V to 0.4V OK).
3. Audio ( low noise ).
4. >=30V. >= 40V preferable.
5. Any power >= 0.6W. Lower may be OK too.
6. Any current >= 10mA. Lower OK. 100mA OK.
7. Complementary OK. Non complementary OK too.
8. Non NTE. Soviet ( Russian ) OK.
 
So far, I have found these :
 
NTE102A (PNP) & NTE103A (NPN). These are not preferable, because, these are very slow. The cutoff frequency of a common emitter amplifier of Beta ( f ) is only 10KHz. Therefore, assuming a slope of 20dB/decade, Beta decreases by, approximately, 6dB at 20KHz. This means, Beta at 20KHz is nearly half of the nominal. In case, however, the slope is steeper than 20dB/decade, which, is possible in case of a multiple order filter equivalent effect, then, the situation becomes tragic.
 
There are a couple of higher power NTE with similar cutoff frequency problem.
 
MP37B ( 30V ) is OK. Cannot find complementary. Please, inform. Please, provide a number or name.
 
1. GT402G and GT404I ( 40V )
2. AC128 and 2SD128A ( 30V, 32V )
 
PLEASE, BE HELPFUL. PROVIDE NUMBERS. YOUR OPINIONS ARE EXTREMELY IMPORTANT, YET, NOT HELPFUL IN THIS CASE. NUMBERS OF TRANSISTORS ARE. One of the ways is to provide numbers of popular Germanium transistors. Of course, complementary audio rated transistors are extremely welcome. Others are OK too. Probably, people remember popularity.
 

PRR

Re: Germanium Transistors! Help!
« Reply #1 on: November 24, 2021, 02:14:23 AM »
Steven, you have been flooding another forum with your unending thoughts. Don't start that here.

Silicon drove-out Germanium, not because it was cheaper (it surely wasn't), but because Silicon is BETTER.

Silicon is not "sand", but a very select sand with a billion dollars of processing investment. The cost is OK.

Germanium is found in coal, and we still use a lot of that. It would be cheap if the world needed a ton of it a year. It doesn't.

Ge has some slim advantages, and they still make Tunnel Diodes of the stuff. But all other Ge applications, even the high-power where great conductivity and low Vbe counted, have dried-up.

And Welcome!
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Kevin Mitchell

Re: Germanium Transistors! Help!
« Reply #3 on: November 24, 2021, 08:10:48 AM »
Hey, welcome to the forum!
You may get lucky and someone will chime with with pre-existing knowledge on complimentary germanium devices or a pair that can be used as such. However, most of us will not do the leg work and do the search for ya. Having specific requests for no longer manufactured devices may be asking for much. So perhaps you can adapt your design to work with the next best scenario. No matter, you're going to have to grab a bunch of them and sort through unless you find the golden ticket complimentary part.

Best of luck!

Also,
PRR sees all  :o
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I'm archiving all of my DIYLC work for the home-etchers - Project Layouts & Templates

iainpunk

Re: Germanium Transistors! Help!
« Reply #4 on: November 24, 2021, 08:27:21 AM »
welcome to the forum

i know for a fact that Philips sold matched pairs of AC187/AC188 in a single blister. in fact, i have such an unopened blister. here

i know that, once in a while, matched pairs of this type are sold on ebay for about 6 to 10 dollars.

what do you need them for? Si transistors are better in almost every regard, and the points they are worse at, we are able to design around.

cheers
« Last Edit: November 24, 2021, 08:29:47 AM by iainpunk »
friendly reminder: all holes are positive and have weight, despite not being there.

cheers

Re: Germanium Transistors! Help!
« Reply #5 on: November 24, 2021, 10:08:41 PM »
Steven, you have been flooding another forum with your unending thoughts. Don't start that here.

Silicon drove-out Germanium, not because it was cheaper (it surely wasn't), but because Silicon is BETTER.

Silicon is not "sand", but a very select sand with a billion dollars of processing investment. The cost is OK.

Germanium is found in coal, and we still use a lot of that. It would be cheap if the world needed a ton of it a year. It doesn't.

Ge has some slim advantages, and they still make Tunnel Diodes of the stuff. But all other Ge applications, even the high-power where great conductivity and low Vbe counted, have dried-up.

And Welcome!

 
I am not flooding forums. I, ONLY, NEED GERMANIUM TRANSISTORS AND NEED NUMBERS. Although I thank you for your opinion, I do not need this and is, therefore, not helpful. In regards for prices of Silicon and Germanium, Wikipedia says opposite to what you say, but, again, this is not important. Again, I AM, ONLY, INTERESTED IN THE NUMBERS OR NAMES OF SUITABLE GERMENIUM TRANSISTOR AS PER THE POST. I have posted what I have found and what may work as well as what may not work, so, people do NOT give these numbers, because, I already have them.
 

Re: Germanium Transistors! Help!
« Reply #6 on: November 24, 2021, 10:21:10 PM »
Hey, welcome to the forum!
You may get lucky and someone will chime with with pre-existing knowledge on complimentary germanium devices or a pair that can be used as such. However, most of us will not do the leg work and do the search for ya. Having specific requests for no longer manufactured devices may be asking for much. So perhaps you can adapt your design to work with the next best scenario. No matter, you're going to have to grab a bunch of them and sort through unless you find the golden ticket complimentary part.

Best of luck!

Also,
PRR sees all  :o

 
The reason I have asked this forum is, because, people in this forum know a lot in regards to Germanium transistors. In other forums, people do have some knowledge, but, not as much as here. Therefore, I am sure, people in this forum have used Germanium transistors and are very knowledgeable. Thanks.
 
Again, I thank you for your opinion, yet, I am interested, ONLY, in numbers and names. I do not ask anyone to do searches instead of others. I am sure there are people who have used what I ask for and can, just, type a few numbers for a few seconds. Also, searches may be next to impossible in some cases.
 

Re: Germanium Transistors! Help!
« Reply #7 on: November 24, 2021, 10:25:26 PM »
welcome to the forum

i know for a fact that Philips sold matched pairs of AC187/AC188 in a single blister. in fact, i have such an unopened blister. here

i know that, once in a while, matched pairs of this type are sold on ebay for about 6 to 10 dollars.

what do you need them for? Si transistors are better in almost every regard, and the points they are worse at, we are able to design around.

cheers

 
Thank you so much for your help. Your post is one of a few helpful. AC187 / AC188 is a good suggestion, however, they are only 15V. I am interested in, ideally, >= 40V, but, >= 30V may be OK. This is for the lowest voltage.
 

Re: Germanium Transistors! Help!
« Reply #8 on: November 24, 2021, 10:32:37 PM »
Buy mine.

https://reverb.com/item/47107023-germanium-transistor-grab-bag

 
Thank you! This is helpful. Yet, I am interested in specific numbers. I hope, you understand. Otherwise, your price is great! I am so sorry, you have decided to switch to other parts.
 

tonyharker

Re: Germanium Transistors! Help!
« Reply #9 on: November 25, 2021, 06:24:40 AM »
If you told us what you need them for we may be able to help further.

mozz

Re: Germanium Transistors! Help!
« Reply #10 on: November 25, 2021, 01:30:44 PM »
Really shouldn't comment but searching for this name under google really shows a bunch of odd stuff he is into. Not to say i don't have varied interests.

 If you tell us what numbers you are looking for or what the circuit is, we may be able to help.
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iainpunk

Re: Germanium Transistors! Help!
« Reply #11 on: November 25, 2021, 03:12:41 PM »
i searched 3 different databases and i can't find any Ge NPN available anywhere that fits your parameters, enough PNP tho. the OC81 is a great PNP transistor.

cheers
friendly reminder: all holes are positive and have weight, despite not being there.

cheers

Phend

Re: Germanium Transistors! Help!
« Reply #12 on: November 25, 2021, 03:19:40 PM »
Try SMALL BEAR
But you better be fast they are closing soon, like Dec 3, no more orders.
Look at their website, maybe give em a call.
« Last Edit: November 25, 2021, 03:22:05 PM by Phend »
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I quit, it's easy to quit, I've quit hundreds of times

tonyharker

Re: Germanium Transistors! Help!
« Reply #13 on: November 25, 2021, 03:44:17 PM »
AC176 Vce 20v Hfe 52.
AC127Z Vce 40v Hfe 25

Here's some more NPNs




ElectricDruid

Re: Germanium Transistors! Help!
« Reply #14 on: November 25, 2021, 04:22:09 PM »
Welcome Steven.

You'll get better responses IF YOU DON'T SHOUT! and if you tell us what you're trying to do so we can help. People around here like to be helpful, but being TOLD JUST TO PROVIDE NUMBERS without any additional information just comes across as someone who wants something for nothing, without even telling anyone what you need match Ge NPN/PNPs *for*. And believe me, most stuff that such a pair might be good for will have been tried by someone here, so you're in the right place. Some of the requirements you're placing on the mythical transistor pair you're looking for look unrealistic to me. Germaniums aren't famous for their low noise or matching, even from one unit to the next, or one degree of temperature to the next, or one minute to the next

So how about trying again, opening up a bit and telling us what your project is, and then we'll be able (or at the very least more inclined) to help you.
 

pinkjimiphoton

Re: Germanium Transistors! Help!
« Reply #15 on: November 28, 2021, 10:33:57 PM »
honestly, NUMBERS don't mean SHIT.

you're gonna have to do what we all have to end up doing. search and search, and buy a shit tonne of them and see what works. they are so completely @#$%ing inconsistant that there is no way to go and suggest any particular numbers as being "good".

every germanium transistor is different. and every @#$%ing one of them is gonna read different every time you check it, depending on temp, humidity, cycle of the moon, you name it.

look on ebay. buy bulk lots where you can affordably. try them, test them, see what works and what doesn't. you'll get a LOT farther doing that than you will asking anyone for advice on a topic impossible, literally impossible, to answer in the way you hope for.
 
any "number" you get, any number of them, you're gonna get some that work, some that don't, some that are hissy or noisy, and maybe a couple decent ones.

that's the reality of germanium. its harder and harder to find decent nos stuff, cuz the newbs once they find something somewhere tend to buy them all up, completely depleting the supply of decent q's out there.

finally, if you can't or won't share what it is you need them for, that's like asking us what kind of car to drive. it makes no sense.

help us help you. but portraying an attitude about not wasting your time while wasting ours isn't really the best way to find the info that you seek.
idy:
like tone haiku
Quote:
         The capacitive burden is now shifted from the passive pickup to the buffer.

The capacitive
burden is now shifted from
pickup to buffer.

#FuzzyGoodness

danfrank

Re: Germanium Transistors! Help!
« Reply #16 on: November 29, 2021, 04:18:49 PM »
That's your opinion and NOT helpful...

In all seriousness, please be kind. This is aimed at no particular person in general... Some people can figure out the rules of life and etiquette quite easily while others  have a harder time. It's all a spectrum, the range of different peoples personalities. I really try to keep in mind that everyone is trying the best they can, some come off better than others.

PNP                NPN
2N1303          2N1304
2N1305          2N1306
2N1307          2N1308

Yeah, I know, voltage is only 20-25 volts. Your best bet is to get old transistor data books (I'm sure there's some online) and go through them to find complimentary pairs. Everything everyone has said above is true so I wouldn't rely too much on part numbers, they don't matter much.

Re: Germanium Transistors! Help!
« Reply #17 on: December 18, 2021, 04:51:53 PM »
Thanks to people who posted important posts.
 
As for the rest, freedom of speech!
 
In regards to shouting, I do not shout. Some idiot, decades back, decided CAPITALS re shouting. Never heard a bigger stupidity. CAPITALS ARE FOR READABILITY. Thus, important things must be in capitals. THE READABILITY OF CAPITALS IS MUCH BETTER THAN THIS OF BOLD, ITALIC, ETCETERA.
 
In regards to Germanium transistors, I forgot to mention I need them to be as fast as possible, i. e., as high slew rate as possible.
 
Anyway, for those interested :
 
GT402 and GT404

Attached is the English translation of GT402 and GT404. These transistors are amazing for audio.

They have a high leakage current of <= 25uA. This must be considered for high Beta Sziklai configuration.

Also, with ft = 1MHz, these are very slow for some applications. I forgot to mention, I need extremely high speed transistors.

When huge speed is not of concern, these transistors are ideal and, still, available.

Please, inform in case of any mistakes. Scroll down for the original, USSR, documents.

Here are the documents :

https://drive.google.com/drive/folders/1xH0_UTeCrvTPOc40wg_NzldcV2bCAMNh
 

iainpunk

Re: Germanium Transistors! Help!
« Reply #18 on: December 18, 2021, 05:38:27 PM »
Quote
Some idiot, decades back, decided CAPITALS re shouting.
not 'some idiot' but lots of different communities have independently come to the conclusion that ALL CAPS MEANS SHOUTING, this concept far predates the internet tho, it was already accepted in writing.
its also common internet etiquette to regard all caps as shouting, and when in Rome, do as the romans do

also, aren't those GT402 // GT404 to low a voltage for your purpose? iirc they are only 20v, and you asked for 40v
they are also really REALLY noisy,

slew rate isn't a thing with single transistors, only with whole circuits. for slew rate to be a thing, a constant current needs to be in play, in combination with a capacitor or inductor, so it charges- or fluxes-up in a linear fashion, not in a curve like with a resistor feeding it.
the speed of a capacitor has to do with miller capacitance, if you want a fast transistor, do NOT use Germaniums.

why do you want to use Ge so bad? the ONLY advantage they have is a slightly lower forward voltage, all other specs are worse, WAY worse.

cheers
friendly reminder: all holes are positive and have weight, despite not being there.

cheers