These three ocp71s are a bit of transistor history. This looks like the ubiquitous to18 package as used by the bc108 and similar but with a forth lead for the screen. A great book for learning electronics in easy plain language. Is there anything available to see if a particular transistor can be replaced with a different one. Free transistor circuits books download ebooks online. Apr 05, 2008 i during 80s and 90s, i used to search for components equivalents in books. So called equivalent parts, or nte replacements, may not work at all in some cases, because they were worse in some spec, or the circuit was designed with the assumptions that the part had a fairly low bandwidth. Data on many transistors is available on my valve data cdrom.
This book also has a very comprehensive glossary, index, and equations. In the spring of 1945 a major meeting was called to discuss the future research into them this was a pivotal point in the transistor history. It is necessary to ensure that the replacement transistor will be able to operate at the relevant frequencies, so a similar or slightly higher ft is advisable. Semiconductortransistor crossreference list peavey. Or, point me to an article that explains transistor specifications and how to read them. Imo, the 2 transistor books i got need a good instructor to clarify basic concepts like flow of electrons and holes, reverse bias, forward bias, etc. Choosing transistor replacements electronics notes. The set is built on an aluminium chassis with the transistors, if cans, transformers and larger capacitors on top, and the smaller components underneath. Cross reference universal transistor reference read 980 times. Oc74 datasheet, equivalent, cross reference search. Oc71 datasheet, cross reference, circuit and application notes in pdf format.
Cross reference universal transistor reference page 1. Maximum power, called p d, is the overall power a transistor can dissipate, through heat, without burning up. If not, it can usually be obtained from transistor data books. Phototransistors are a form of transistor that is sensitive to light having the gain of a. Aug 21, 2014 general electric transistor manual if that link goes away, you can sometimes find it for absurd. The following diagram and paragraph are taken from the book electronic. The lead connections of the transistors are often included in the service data for the set.
Everyday low prices and free delivery on eligible orders. Philips described its pointcontact transistors in general terms as follows. The problem is not as universal as with the af117 series however, and replacement with a similar transistor from a scrap set will often be a permanent solution. Transistor equivalents for the substitution of modern. In this case, before fitting a replacement transistor, check the associated bias components. The image shows the oc71 glass case, painted black, with below it the oc72, a higher power type, achieved by slipping an aluminium can over the glass tube. The best equivalent transistors are the af12x series that are the same piece of. Dont go for a transistor with a much higher ft as this may increase the risk of oscillation.
They were designed as phototransistors, but as far as their use, they can be seen as oc71s without the black. Transistor equivalents for the substitution of modern transistors in elderly projects. Cross reference universal transistor reference page 1 eevblog electronics community forum. Oc71 germanium transistor buy, price, stock, siliconark. Oc71 datasheet, equivalent, cross reference search. Nte is a company that specializes in cross referenced parts. What books should one use to study mosfet, bjt transistor. They are very similar to the characteristics of a conventional bipolar transistor, but. Articles transistors in vintage radios marks pages home.
Free package of programs to work with pdf and djvu files can be downloaded here. The cv7003 is a lowpower germanium pnp switching transistor equivalent to the gec type get874, the mullard type oc44 and the stc types tk31c and asy55. Or if you know the transistor you need then simply type the first 4 or digits in the above search box. Hello everyone, ive just been flicking through a few old transistor applications books and noticed most if not all used pnp transistors and negative power supplys, however the vast majority of circuits ive seen in british electronics books from the 70s to 90s have almost always used npn transistors and standard power supplies. The transistor handbook, one in a series of component handbooks, has the answers to all of your daily application questions. A vintage ocp71 phototransistor this was an oc71 transistor with opaque encapsulation. Introduction to the design of amplifiers, receivers and digital circuits 9 by amos, stan w. The best equivalent transistors are the af12x series that are the same piece of germanium, but mounted in a to72 case. General electric transistor manual if that link goes away, you can sometimes find it for absurd.
Other schematic diagrams and service manuals can be downloaded from our free online library on electronics. Heat sinks and fans increase the ability of a transistor to dissipate heat. I have an extensive collection of original data sheets and books, and can. The ac128 is a good generalpurpose replacement for oc71, oc78 and oc81. Bipolar, power, rf, digital, igbt, unijunction, fet, jfet, and mosfets. For the pointcontact transistor a small slab of ntype germanium consisting of a single crystal and having a volume resistivity of 5. Bipolar power transistor selection guide january 2003 table of contents product page general purpose transistors horizontal deflection output transistors product page dpak d2pak sot223 ipak to126 todarlington transistors dpak ipak to126 to220 to220f to3p to3pf switching transistors dpak d2pak to92 to126 to220 to220f to3p to3pf 2. Ive quoted figures from a mullard data book published in 1979.
Low power af amplifier transistors like the oc71 can be replaced with. Others, discontinued transistor data book 1975, scan, pdf. Overall number of data sheets in free reference books we offer is over 20,000. Some pages missing but still a useful source of info. International transistor equivalents guide bernard babani. The first germanium transistors that i encountered as a kid were the glassencapsulated ocxx types oc44, oc45, oc71, oc81d, oc81, etc.
Vrt comparison table for semiconductors from a to z. Free transistor equivalent book transistor bipolar junction. There are books galore on this but surely someone knows of a site that has them listed and searchable my query is a simple one i have no 2n5551 transistors on hand and i want to see if one in my box will do the job. I show three examples, one in classic gec lowpower encapsulation, one in a mullard so2 glass can, and a third in a short so2 or to1 metal can probably made by texas instruments uk. The tr55 was quite similar to the regency tr1 in many ways, being. Historical vintage mullard ocp71 phototransistors equivalent to.
Transistor semiconductor history texas instruments rca bell laboratories western electric general transistor fairchild tungsol sylvania mullard philips stc newmarket general electric philco gec motorola shockley faraday willoughby smith william adams richard day charles fritts braun schuster henry round jagadis bose greenleaf pickard alan wilson walter schottky boris davydov nevill mott. Should you find any info that can fill in any of the blanks in the matrix below. The links at left may help you to research your own replacement transistors. Transistor pnp germanium 32v 1a to1 medium driver order for or more ship same day or within 48hrs. Uk vintage radio repair and restoration transistor faults. In the 1950s and 1960s, hundreds of hobbyist electronics projects based around the ck722 transistor were published in popular books and magazines. In practice, the af125 can be used to replace af114115116. Mullard soon switched to using the bc prefix for silicon, and ac for germanium, eliminating the confusion. Mullard then developed a unique glass encapsulation, and in 1954 issued three new alloyjunction audiofrequency transistors, the oc70, oc71 and oc72. There is no listed equivalent to the af118 and where replacement is needed for an old transistor tv, it may be necessary to rejig the circuit to take a suitably rated silicon device. Another point to watch is that equivalent books list the af239s as a. High voltage 75v video amplifier for transistor tvs.
Used in some historical three transistors fuzzboxes like the marshall supa fuzz and some 2 transistors tone benders. Buy principles of transistor circuits, ninth edition. Also as with any transistor set look for damage caused by leaking batteries. A to5 transistor with a p d of 3 watts might be able to dissipate 810 watts with a heat sink. Germaniumtransistoren by transistorvergleichsliste and a great selection of related books, art and collectibles available now at. Vrt comparison table for semiconductors from a to z edition. Still, to me transistors are very technical i need a transistor book that is about 8th grade level with more diagrams. Buy online discounted oc series transistors from silicon. This easytouse book covers all transistor types including. Others, shortform transistor datasheet guide, scan, pdf. Uk vintage radio repair and restoration transistor. Sample pages of the vrt comparison books from eca edition 20102011 vrt volume 1 from a to z split into 2 books vrt1a and vrt1b 1496 pages isbn 9783937469379 vrt volume 2 from 0 to 680 pages isbn 9783937469386.
Mullards first silicon transistors were the oc201 to oc207, pnp alloy types using the standard so2 metaloverglass construction such as the oc201 shown. Many times the equivalents shown in the various books are harder to find than the original component. Semiconductor cross reference book engineers of howard w. Rca transistor thyristor and diode manual sc14 and a great selection of related books, art and collectibles available now at. Becoming an engineer supplier directory books events.
Vintage mullard semiconductors andrew wylies watercolours pages. The sound quality is good, and puts many of todays transistor radios to shame. This seems to affect many audio transistors including oc71, oc78, oc81, ac127, ac128, ac176, ac187 and ac188. Rangemaster treble booster clone, freaking awesome.
Mullard data book, 19734, mister transistor and other websites see references. If you continue without changing your cookie settings, well assume that you are happy to receive all cookies on our website. Uk vintage radio repair and restoration bush transistor sets. Does anyone know of a chart anywhere that list some of the common transistors you see in pinball circuit boards and their equivalent from different manufacturers.
As hostilities started to draw to a close, bell laboratories realised that there were major possibilities for semiconductor technology. Jul 21, 20 ive just been flicking through a few old transistor applications books and noticed most if not all used pnp transistors and negative power supplys, however the vast majority of circuits ive seen in british electronics books from the 70s to 90s have almost always used npn transistors and standard power supplies. Texas instruments transistor and diode databook 1st ed 1973 datasheets for diodes from 1n251 on and transistors from 2n117 on acrobat 7 pdf 34. Aug 25, 2011 crossreferences are not magic, understanding of the circuit and a parametric search of the important parameters is much more reliable. These models are very fragile, sensible to static electricity, and therefore to avoid. Buy international transistor equivalents guide bernard babani publishing radio and electronics books by adrian michaels isbn. This section contains free e books and guides on transistor circuits, some of the resources in this section can be viewed online and some of them can be downloaded. They have a fourth connection, enabling the housing of the transistor to be connected to ground. One of the larger surfaces of this germanium slab is soldered on to a metal carrier and thus forms the base. This is where you will find all the transistors specifically in the oc series i. Buy online discounted oc series transistors from siliconark.
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