what can I do with a box of very old germanium transistors? - Page 1
Forum section: electronics / general

author: cdev
author_rank: Super Contributor
timestamp: January 18, 2016, 06:13:06 am
content: Going through my old parts boxes, I just found a bunch of old geranium transistors acquired from an estate sale. They are truly antiques, some of them look like prototypes.They are in little boxes painstakingly hand-marked with their Beta, Vbe, etc.Most are PNP transistors.

author: ataradov
author_rank: Super Contributor
timestamp: January 18, 2016, 06:41:15 am
content: At least take some pictures and post them here.

author: Galenbo
author_rank: Super Contributor
timestamp: January 18, 2016, 08:41:22 am
content: Quote from: ataradov on January 18, 2016, 06:41:15 am:-)Or make a video, and become rich and famous :-)

author: krivx
author_rank: Frequent Contributor
timestamp: January 18, 2016, 08:47:43 am
content: Certain part numbers are sought after by people building guitar pedals, they could be worth putting on eBay

author: eeadata
author_rank: Contributor
timestamp: January 18, 2016, 08:59:14 am
content: Part Numbers and pics please...

author: TerraHertz
author_rank: Super Contributor
timestamp: January 18, 2016, 12:40:07 pm
content: You can post them to me, please. Then I post pics of them here.Well, you did ask as if you didn't know.

author: klr5205
author_rank: Regular Contributor
timestamp: January 18, 2016, 12:46:30 pm
content: Quote from: krivx on January 18, 2016, 08:47:43 am+1 to this. Germanium transistors are claimed to be a big tonal factor in the old Fuzz Face pedals.

author: cdev
author_rank: Super Contributor
timestamp: January 18, 2016, 06:55:16 pm
content: Photo - As you can see they are not in the greatest condition.The person who's estate sale they came from had been an electronics design engineer but he had retired a very long time ago.Some of the labels are wrong, for example, the 2n1108a is actually - hmm-Actually, it looks like some of the tops are on the wrong boxes. So i need to revisit this a bit later to make an inventory of them. I will try to do it today. Most of them are legible but a few aren't or are hand written.Edit: Looking up the part numbers on Ebay, they don't look to be worth much in the condition these are in. I am more interested in what I could do with them, electronically. Since they are kind of unusual.

author: krivx
author_rank: Frequent Contributor
timestamp: January 18, 2016, 07:01:48 pm
content: I know those RCA 2n404s will fetch a few bucks

author: cdev
author_rank: Super Contributor
timestamp: January 18, 2016, 07:10:45 pm
content: What makes germanium unique?

author: dannyf
author_rank: Super Contributor
timestamp: January 18, 2016, 07:13:14 pm
content: They are actually in great condition, given the age.Unfortunately, not much practical uses.

author: eeadata
author_rank: Contributor
timestamp: January 18, 2016, 07:23:37 pm
content: Hfe s are too low for fuzz face. may be it can be use as buffer or germanium diode.

author: retrolefty
author_rank: Super Contributor
timestamp: January 18, 2016, 07:28:45 pm
content: Quote from: cdev on January 18, 2016, 07:10:45 pmLower forward voltage drop. Probably still the diode of choice if you were building a 'crystal radio' today.

author: tautech
author_rank: Super Contributor
timestamp: January 18, 2016, 07:32:15 pm
content: Quote from: cdev on January 18, 2016, 07:10:45 pmThey were the first commercially produced semiconductors from naturally occurring germanium crystals that have an inherent diode action. The switch later to silicon allowed higher power devices to be produced.

author: retrolefty
author_rank: Super Contributor
timestamp: January 18, 2016, 08:44:33 pm
content: Quote from: krivx on January 18, 2016, 07:01:48 pmI remember those. They were a switching transistor of choice on the first digital comm equipment I worked with. It was older equipment even in 1970, soon to be replaced with 74xx ICs.

author: cdev
author_rank: Super Contributor
timestamp: January 18, 2016, 08:56:54 pm
content: Quote from: retrolefty on January 18, 2016, 07:28:45 pmGermanium diodes are really useful for RF, I agree..Actually, I think a "crystal" radio was my first electronics project, when I was a little kid.

author: calexanian
author_rank: Super Contributor
timestamp: January 18, 2016, 10:21:55 pm
content: I would either just hang onto them just in case you need them for a repair down the road, or if you are not too keen I would make it a little project to test them all for hFE, and put the whole lot on eBay. I bet you will find others use them. Just yesterday I cleaned up a radio from a car i am restoring and it uses 7 (Proudly stated on the case it uses 7) transistor model. All germanium. The funny thing is it is a toshiba AM radio from a datsun roadster with mid 1968 date codes on the caps. All the electrolytic caps are Nichicon or Nippon Chemicon, all still good. I just replaced them (with new nichicon) caps just cause. Thing sounds great. I took a video and I may post it.

author: Halvmand
author_rank: Regular Contributor
timestamp: January 19, 2016, 12:05:35 am
content: What about AC176 and AC128 NPN and PNP.I have 30 - 40 of each, never used. I got them from a collegue of mine who at some long time ago worked for B&O.I've got the same amount of 2n2102. They're silicon devices though.

author: Mark Hennessy
author_rank: Frequent Contributor
timestamp: January 19, 2016, 12:30:57 am
content: Quote from: Halvmand on January 19, 2016, 12:05:35 amI use them for restoring old transistor radios from the '60s and '70s. Let me know if you'd like to part with any.

author: TerraHertz
author_rank: Super Contributor
timestamp: January 19, 2016, 12:53:18 am
content: I think given the mix, and that most of them have very short legs but not soldered, that these are mostly parts he salvaged from boards with the transistors in sockets. Using sockets for transistors was very common back then, and those short lead lengths are typical for socketed parts. The few with longer legs would be ones he bought.Rather than try to build anything with them, it's probably better to keep them as-is for historic value. Or sell on ebay as a set.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: January 19, 2016, 01:16:59 am
content: Quote from: Mark Hennessy on January 19, 2016, 12:30:57 amOmg that looks like new! Great restoration work! I bet it looks even better inside!

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: January 19, 2016, 01:26:36 am
content: BTW 2N585 is £7 GBP / piece on Ebay. There is definitely a market for old parts especially for "authentic" restoration.Is there something unique about OLD germanium transistors? Can they be used for niche apps like avalanche pulse generators, noise sources, some other solid state physics experiments etc. where modern versions don't work as well?

author: BravoV
author_rank: Super Contributor
timestamp: January 19, 2016, 01:49:45 am
content: Build a joule thief that beat those silicon based ones with lower start up voltage.

author: retrolefty
author_rank: Super Contributor
timestamp: January 19, 2016, 01:55:14 am
content: Quote from: Alexei.Polkhanov on January 19, 2016, 01:26:36 amWell as a result of this posting thread I checked out E-bay for 2N404. It seems it's mostly desired by guitar players for 'fuzz pedal' applications. So I suspect it's a perceived sound difference not unlike the audio tube enthusiastic crowd. So I say cash in while the market is still hot, but it appears you have to make some attempt at matching pairs for best selling price.

author: rrinker
author_rank: Super Contributor
timestamp: January 19, 2016, 01:57:30 am
content: You could always build an original Twin-T model railroad block detector. Wow, no handy web page with the proper schematic and explanation, oh well, this post is worthless....

author: Mark Hennessy
author_rank: Frequent Contributor
timestamp: January 19, 2016, 11:33:44 am
content: Quote from: Alexei.Polkhanov on January 19, 2016, 01:16:59 amThank youRather than taking this thread OT, I'll point you towards the story and more pictures here:http://golbornevintageradio.co.uk/forum/showthread.php?tid=653I do many other things besides restoration work, but I do find it relaxing and therapeutic. It makes a nice change to deal with older components and techniques, and you really have to admire the designers who were still new to transistors and didn't have the tools (hardwareandsoftware) that we have today.When people talk about the "germanium sound", I suspect that has more to do with the topologies that people were using at the time. For example, a lot of audio amplifiers in those days were using interstage coupling transformers, which restricts the amount of negative feedback you can safely apply. And transistors were incredibly expensive at the time (several £s in today's money) so designers used them very sparingly, which sometimes leads to higher noise and distortion levels that we're used to today. Of course, coming from the valve/tube era, designers were used to getting the most performance from a single active device.

author: SL4P
author_rank: Super Contributor
timestamp: January 19, 2016, 12:59:06 pm
content: Good for white noise and pure random number generation...!

author: German_EE
author_rank: Super Contributor
timestamp: January 19, 2016, 06:07:22 pm
content: Build a Deacy Amplifierhttps://en.wikipedia.org/wiki/Deacy_Amp

author: calexanian
author_rank: Super Contributor
timestamp: January 20, 2016, 02:44:16 am
content: Quote from: Alexei.Polkhanov on January 19, 2016, 01:26:36 amApart from what the purists will tell you about the sound of germanium transistors in fuzz circuits and the like the main technical reason to use them as replacement parts is that the circuits that use them are often designed to take advantage of their very low BE voltage threshold. Using a silicon pnp device may result in improper biasing in linear circuits. I just cleaned up a radio from the Datsun roadster I am restoring. Built in 68 with just 7 transistors. All germanium. It actually sounds quite good for such a simple design. They truly did more with less in those days.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 20, 2016, 04:35:53 am
content: How about a thermal runaway demonstrator? Making one of these run away is easy, the fun part would be putting the controls on so you didn't use up one of your stock each time you demonstrated it.Thermal runaway was the reason silicon took over from germanium. One of my professors was an early TI employee and he told a great story about how TI combined technical expertise with commercial subterfuge in those first commercial silicon transistors. At the time the problem was getting silicon pure enough to then dope and get good junctions. Zone refining was the technology of the day, but single passes weren't delivering the desired results and multiple passes would not be commercially viable in the long run. To get to the market first, and to give the impression of a greater technical lead than they actually had at the time they set up a convoluted scheme where silicon boules would be run through the zone refiner, then spirited off to a "storage room" where the serial numbers on the boules where changed and a secret set of books kept. After several passes through the refiner the boules were of the desired purity. The process gave the impression of both a high level of production and of a superior refining technology. Eventually the processes were dialed in and the financial results began to match the show which had been put on.

author: krivx
author_rank: Frequent Contributor
timestamp: January 20, 2016, 08:20:48 am
content: Quote from: calexanian on January 20, 2016, 02:44:16 amKeep in mind the fuzz circuits are absolutely not linear circuits, nor are they meant to be. The original designs were usually very simple (2 or 3 transistors) and tended to vary with transistor parameters. You can rework them for Si parts but usually you get something that works differently (not necessarily better or worse as that's just preference, but just different).FWIW when I've built this stuff I have been happy with Russian parts, they seem to have continued producing general-purpose Ge parts into the 1980s and the devices are very consistent and conveniently quite cheap. I understand why people like "original" replacements for aesthetics in old equipment or replicas of old equipment though.

author: MrSlack
author_rank: Frequent Contributor
timestamp: January 20, 2016, 08:35:15 am
content: Quote from: BravoV on January 19, 2016, 01:49:45 amNeckbeard time...Germanium transistors would probably die after about five minutes doing that. They died everywhere else.My first experience was with AC127/AC128s salvaged from radios from jumble sales in the early 1980s. Half of them didn't work at all to start with, about half of the other half barely worked and the half of the remaining half worked but only for about an hour. And the successful few? The moment you went near them with the primitive Tandy firestick I had, they died instantly. Apart from an AC128 I had which was named for prosperity (Dave ironically) because I couldn't kill it.Then I spent 10 quid on some 2n2222 units from Tandy/Radio Shack and never looked back other than to lament the repetitive shafting because I bought a sack of 200 Fairchild bc337s from Farnell a few weeks back for the same cash. Ugh.Back on topic, sell 'em to audiofools. I did that it about 2009 on eBay when there was 'peak pedal' and got £5 a transistor. I have been considering buying bulk soviet germanium stuff (Tesla) which is pretty close characteristic-wise from a friend I have in the Ukraine and selling it in Western Europe as the new sound. But then the shame sets in.

author: calexanian
author_rank: Super Contributor
timestamp: January 22, 2016, 06:44:43 am
content: Speaking of early tom foolery in semiconductor sales, I heard in an interview from the computer history museum that the salesmen would sabotage competitors products by various means. The old epoxy blob UFO shaped transistors could be damaged by flicking the top just right. The early TI metal can types could have their characteristics changed by squeezing them between your thumb and forefinger making design engineers think the parts are not holding spec in their designs and going with other parts the salesman just happened to have with him, etc. Wild days. One of the ladies we have had do assembly at our place for 30 years now used to work at Fairchild in the 60's and told us stories i never believed, until I learned the story about the Traitorous Eight. Crazy times.

author: MrSlack
author_rank: Frequent Contributor
timestamp: January 22, 2016, 10:05:14 am
content: Interesting times indeed. Never trust a salesman!

author: Halvmand
author_rank: Regular Contributor
timestamp: January 26, 2016, 08:08:18 pm
content: Quote from: Mark Hennessy on January 19, 2016, 12:30:57 amGood work on that restoration.If we can get them shipped to the UK then they're yours. Given the answers in the thread, I don't think I'll ever use them. Ill keep a couple though.

author: Mark Hennessy
author_rank: Frequent Contributor
timestamp: January 26, 2016, 08:53:26 pm
content: Quote from: Halvmand on January 26, 2016, 08:08:18 pmThank you - that's very kind. I'll send you a PM

author: IdahoMan
author_rank: Regular Contributor
timestamp: October 17, 2016, 02:40:11 am
content: I have a VT-51 Megaphone (rectangle-shape) that does not work. When opening the battery compartment there are two 2SB337 power transistors sitting atop the inside casing. Googling them, they appear to be germanium.Should I suspect them as the problem, or some other cause?The megaphone is dead as a doornail. When germanium transistors fail or are failing, what are the symptoms?I also have a large, portable "all transistor" Zenith shortwave radio. It is germanium, and has a positive ground?Thank you.Sincerely,IM

author: jonovid
author_rank: Super Contributor
timestamp: October 17, 2016, 03:20:51 am
content: Quotenever throw out old electronic components that are in a never used condition & more than 40yr old . very rare electronics - the economics of scarcity =$