Germanium transistors page 1 small bear electronics. Applications ge neral purpose switching and amplificati on. In the seventies, the superior silicon devices began to take over the hobby market. Complementary low voltage transistor stmicroelectronics. Transistor specifications explained electronics notes. Basic semiconductor physics, diodes, the nonlinear diode model, load line analysis, large signal diode models, offset diode model, transistors, large signal bjt model, load line analysis, small signal model and transistor amplification.
Work on power transistors was initiated by neville fletcher who worked at the company while undertaking his phd at harvard university on the theory of energy levels in semiconductors. Diodes and transistors pdf 28p this note covers the following topics. It is painted black, and early examples have wire leads crimped onto the three pins whilst later ones have solder tags instead. Consider a pnp transistor, which is connected in the circuit with the supply voltages v b 1. Transistors germanium mp25 analogue 2n519a, 2n520a, 2n520. Great deals on nos, surplus, obsolete and hard to find electronic parts and components for hobbyists, musicians, audiophiles, amateur radio, swl, restorations, and technicians. Datasheet search, databook, component, free download site keywords. The first germanium transistors that i encountered as a kid were the glassencapsulated ocxx types oc44, oc45, oc71, oc81d, oc81, etc. Motorola 2n59 pnp germanium power transistor motorola new old stock to3 case, gold leads vcbo. Germanium transistors the following table lists the parameters for germanium transistors. The ad 142 is a germanium alloy junction pnp transistor in a jedec to3 metal case.
This project originated as an experiment in how to use the germanium transistors that are left over when sorted for leakage and gain. Has new, new old stock, and obsolete transistors in stock, including hard to find germanium transistors used in restorations, projects, and effects pedals. The 2n107 is an early germanium alloy junction pnp transistor developed by general electric ge in 1955, to become ges entry into the electronic hobbyist market successfully started with the ck722 transistor. For the version mounted in a block of aluminium please see ac188k in related products tab above. Editorial in the june 1954 edition of electronics identified this transistor as the x78 a pnp alloy junction type for use in class b. Make offer germanium transistor output driver, 2n2148, rca bsc 1 pc lot only make offer 4 ti3027 ecg 121 nte 121 pnp germanium audio pwr. The only npn transistors you are likely to encounter are in transformerless output stages.
These were made by etching depressions into an ntype germanium base from both sides with jets of indiumiii sulfate until it was a few tenthousandths of an inch thick. For a pnp germanium transistor you should get the following results. Nte121 datasheet12 pages nte germanium pnp transistor. This transistor reference chart describes in 8 pages several philco transistors. Even germanium tunnel diodes, t1925, t1975 and t1976. Book, and survey the type numbers in that section to select.
Mullard soon switched to using the bc prefix for silicon, and ac for germanium, eliminating the confusion. The nte2 is a germanium pnp power transistor in a to36 type package designed highpower, highgain applications in highreliability industrial equipment. Free packages are available maximum ratings rating symbol value unit collector. The customer is in the focus we want to make sure that customer is the center of attention free technical support if something goes wrong, we will be ready and willing to help. And also this circuit connected with the resistors of r b 200k. When testing a transistor with a screen lead such as the af117 series, check the resistance between the screen and each of the other leads. These can occasionally be found on ebay, usually advertised as germanium devices. Mullards first silicon transistors were the oc201 to oc207, pnp alloy types using the standard so2 metaloverglass construction such as the oc201 shown.
Like pnp alloy, sbt, mat, sat, madt, sadt, spat types. Pnp transistor circuit characteristics, working, applications. If not, it can usually be obtained from transistor data books. The latter types listed were often further encapulated in an aluminium can for improved heat dissipation the oc81d was often used as a driver ahead of an interstage phasesplitting transformer, and a. They are designed for audio amplifiers and drivers utilizing complementary or quasicomplementary circuits. Germanium transistor assortment 20 pcs npn pnp hfe fuzz gain. General electric decided to designate it with a jedec 2n series identification. Silicon germanium transistor npn pnp mosfet thyristor triac power. Most car radios had 1 transistor but some radios had 2.
Last page shows the packages outline from to1 till to31. Pnp germanium transistors switches tools connectors and plugs antennas, antenna parts vacuum tubes, nixie tubes instruments, meters, gauges fuses, circuit breakers wire and cable fans, coolers, heatsinks electronic. Valve tube and transistor with informationprojects and technical help. This is the fee to have germanium transistors tested for gain and leakage. Texas instruments transistor and diode databook 1st ed 1973 datasheets for diodes from 1n251 on and transistors from 2n117 on acrobat 7 pdf 34. Redesign germanium transistor circuits, part 1 today. At that time transistor products was producing germanium from germanium dioxide. Transistor manufacturers issue specification sheets for their transistors which are typically found on the internet, although years ago engineers used to study data books to find out the information. The transistor museum store has been established to provide an easily accessible and reasonably priced source of unique and historic transistors, diodes and integrated circuits from the early days of this exciting technology. The nte121 is a germanium pnp alloy junction transistor in a to3 type package designed as an audio frequency power output amplifier. Bc556 transistors datasheet pdf purpose transistors.
It is not hifi and i would not recommend it for design into a new commercial product. Nte2 germanium pnp transistor high power, high gain amplifier. I remember building a pa system with 1 transistor, mic, battery, speaker, 1 resistor, 1 capacitor. With our transistor inserted correctly, the hfe measurement should be within the specification of our part. Aug 08, 2011 the very old ac128 germanium transistor had a different baseemitter voltage requirement compared to a silicon transistor and had a poor high frequency response so it will sound different to a silicon transistor. The first highfrequency transistor was the surfacebarrier germanium transistor developed by philco in 1953, capable of operating up to 60 mhz. Germanium pnp transistor, ad162 loging electronics. To permit ease of consultation, this book has been divided into five main sections. I happen to believe not actually know that the maximum voltage gain occurs when the collector current is approximately 3 to 4ma, so i selected a common resistor value that would provide this current. Uk vintage radio repair and restoration transistor faults. The column marked case is the outline of the transistor case.
In the early years of bipolar transistor usage, most transistors were made from germanium semiconductor materials. Germanium transistor assortment 20 pcs npn pnp hfe fuzz. Mar 09, 2019 who remembers the ds501 germanium power amp transistors that was in the 1960s car radios. Anyway, the problem with these transistors is not the germanium itself rather, its the package the transistors are mounted in. Build germanium transistor projects with silicon transistors. Make offer 2x matched hfe170 gt23 germanium pnp pair fuzz transistor sft323 ac128 23. Transistor museum construction projects point contact. This is a legitimate question and still another nuance to the single transistor amplifier.
Return with us now to the halcyon days of germanium germanium transistor projects intrigued experimenters from the early days in the 1950s until the early 1970s. A bipolar junction transistor bjt is a type of transistor that uses both electrons and holes as charge carriers. For electronic circuit design, selecting the right transistor will need several of the transistor parameters to match the requirements for the. There are many different transistor specifications defining aspects of a.
Transistors germanium mp25 analogue 2n519a, 2n520a, 2n520 ussr 25 pcs by s. Discrete semiconductors data sheet book, halfpage m3d186 2n3906 pnp switching transistor 1999 apr 23 product specification. The ac128 is a great sounding germanium transistor but if you buy many of them, there will be a large number left over that have too much basetoemitter leakage to be useful in a voltage amplifier circuit. Nte electronics nte102a pnp germanium complementary transistor for medium power amplifier, to1 case, 1a collector current, 32v collectorbase voltage. A pnp transistor needs a negative supply its main terminal current flows from emitter to collector, and is controlled by an emittertobase input current that flows to a negative bias voltage. You simply want to match these holes to your part leads. Transistor applications, rca transistor manual t h is book has been prepared to assist. A site for the novice or established collectorrestorer of vintage radio sets and electronics. Transistor pnp germanium 32v 1a to1 medium driver package quantity. Spare electronic parts has new, new old stock, and obsolete transistors, fets, jfets in stock, including hard to find germanium transistors used in restorations, projects, and effects pedals. Indium electroplated into the depressions formed the collector and emitter. You will need to buy one of item ge transistor testing fee in the germanium transistor category for each transistor you want tested. The to7 encapsulation has a 4th lead that is connected to the metal can, and this is usually connected to ground so that the transistor inside is screened.
We also have new old stock ecg and rca sk transistors in stock and ready for delivery. Sgsates, consumer transistor and ic data book 197576, scan, pdf. For the radio constructor we have an archive of vintage circuits schematics to build. The history of the development of transistor products power transistors has been extensively described by joe knight at the transistor museum site knight 2007. Most germanium transistor production ceased in the 1970s in favor of silicon which are more stable, consistent, have higher gain, and lower leakage. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current flowing between two other terminals, making the device capable of amplification. The customer is in the focus we want to make sure that customer is the center of attention free technical support if something goes wrong, we will be ready and willing to help large selection we give you all brands from the world, including. Uk vintage radio repair and restoration transistor. Like the ck722, it enjoyed a longstanding popularity. Fluke, mikroelektronika, knipex and logitech comfort flexible options, including door to door. But many people to this day favor germanium transistors in fuzz pedals because of their tone, and because they want to recreate fuzz tones of their favorite players who used germanium fuzzes. Germanium pnp transistor, 2sb492san loging electronics. Data sheet book, halfpage m3d111 2n4036 pnp switching transistor 1997. Data on many transistors is available on my valve data cdrom.
Complementary low voltage transistor features products are preselected in dc current gain application general purpose description these epitaxial planar transistors are mounted in the sot32 plastic package. If the hfe measured matches our expected hfe for our part, then the transistor is good. On the small bear fuzzface faq, there is a drawing that illustrates how to measure transistor leakage near the end of the page. Matched set of cv73512n8 npn ge germanium transistor for.
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