Ck722 transistor equivalent pdf

Here is a front view of mikes ck722 regen receiver. A transistor is a threeterminal semiconductor device that can be used for amplification, switching, voltage stabilization, signal modulation and many other functions. The ck722 was the most popular transistor ever made. International transistor equivalents guide american radio history.

Thousands of radio kits using the ck722 were made in the 1950s and 1960s. Bohrs regen receiver on page 9, he decided to build one. A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. Pdf bc196a 200mi bfs32p bfs33p bfs34p ns6205 200m5a 200ms 10on0 200m5 ck722 sa495 sac440 ck721 sa537 ck725 sa538 10de1 2sa525. It is composed of semiconductor material with at least three terminals for connection to an external circuit. Although the boys never came across one of norm krims ck722 transistors in their. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. 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. Nov 17, 2016 k3561 datasheet nch transistor, vdss 500v toshiba, 2sk3561 datasheet, k3561 pdf, k3561 pinout, k3561 equivalent, k3561 data, circuit, k3561 schematic. Others, shortform transistor pdf datasheet, scan, pdf. I once broke a leg off my ck722, i was a teenager and couldnt afford to buy another one, so i peeled the blue metal cover off and some gooey stuff, and there was a smaller, silver. Sep 25, 2016 k3878 datasheet pdf nch mosfet toshiba, 2sk3878 datasheet, k3878 pdf, k3878 pinout, k3878 equivalent, data, circuit, output, ic, k3878 schematic. If i ever manage to aquire one, id keep it aside as a collectors item anyway. A voltage or current applied to one pair of the transistor s terminals changes the current through another pair of terminals.

Variations of the circuit have appeared in numerous publications, including the widely distributed volume ii raytheon transistor applications booklet from 1957. Raytheon got into the act too, introducing their transistors, especially the ck722, to the hobbyist market with the publication, raytheon transistor applications, more than 50 practical circuits using raytheon ck722 transistors. K3561 datasheet n ch transistor, vdss 500v toshiba. Discrete semiconductors the vintage technology association. The ck722 was the first lowcost junction transistor available to the general public. In the 1950s and 1960s, hundreds of hobbyist electronics projects based around the ck722 transistor were published in popular books and magazines. Favorite bjt transistors, sot23 and to92 equivalents i.

Raytheon ck722 transistor introduced in 1953, the raytheon ck722 was the first commercial transistor available over the counter for hobbyists and experimenters. The raytheon ck722 germanium pnp transistor is a low performance bin of the ck718. The 2n107 was a later transistor, than the ck722, but has always been a suggested sustitute for the ck722. Although on semiconductors cross reference devices are functionally comparable to other manufacturers published information, we. Even for the same transistor type the terminal assignment can vary normally indicated by a suffix letter to the part number, q. Elektronische bauelemente pnp plastic encapsulated transistor.

Various types of transistors have been developed, increasing the frequency response by reducing noise levels and increasing its power capacity. Transistor academic dictionaries and encyclopedias. More than 50 practical circuits using raytheon ck722 transistors keywords. Pdf bsw88 200msa 15on0 bsw89 bsx81 200m5a bsx81a bsx81b germanium transistor ck722 ck722 ck721 ssa480 2sc912 sa52b sa537 2sc621 2sa525 2n3400. Select a replacement transistor with equivalent ft. When ive built a circuit in the past that called for a ck722, ive found that a 2n404 has worked as a substitute for me.

Sure, the 2n404 has more gain and less leakage, but it worked. Aug 01, 2016 raises collector load reactance at rf to increase stage gain. The information presented in on semiconductors cross reference tool is based on our best estimate of other manufacturers published information at the time that we collected this information. Introduced by raytheon in early 1953, the ck722 was the first low cost junction transistor available to the general public. Ck722 germanium transistor construction projects new volume. Choosing transistor replacements electronics notes. Kt805 datasheet, kt805 pdf, kt805 pinout, equivalent, replacement transistor etc, schematic, circuit, manual. Ck721 datasheet, equivalent, cross reference search. What would be a modern equivalent of the ck722 pnp germanium transistor. The story of the ck722 ck722 classic germanium transistor. Hi guys, im in the half of engineering, so i dont have much experience yet.

Welcome to the ck722 classic germanium transistor website and museum the ck722 holds a unique place in the history of the transistor. The transistor, on the other hand, is a currentoperated device and has a rather low input impedance in the grounded base or grounded emitter connection which is analogous to the fig. Mar 11, 2010 the 2n107 was a later transistor, than the ck722, but has always been a suggested sustitute for the ck722. It was an instant success spurring the creation of hundreds of kits and a large number of ck722 circuits over the next several years. Ck722 classic germanium transistor webpage and museum index. This 50 th anniversary ck722 radio is an accurate and faithful version of these early and memorable projects. Ck722 datasheet, equivalent, cross reference search.

This is is the philco 2n207, the first attempt at a commercial microminature transistor in the to23 package while electronics transistor corp put out their 2n207 in a big to5 but otherwise with very similar specifications. Application of the ck722 pnp junctiontype transistor in singlestage and cascaded amplifiers and analytical bulletin of the committee of coordination of the telecommunications of the french union. A voltage or current applied to one pair of the transistor s terminals controls the current through another pair of terminals. A transistor is a semiconductor device used to amplify or switchelectronic signals and electrical power. So i would appreciate your help to tell me how i can replace those transistors, because i think they are very old.

Dont go for a transistor with a much higher ft as this may increase the risk of oscillation. Transistor packages are mainly standardized, but the assignment of a transistor s functions to the terminals is not. The secondary of t2 may he connected di rectly to the base input circuit of a similar amplifier stage. Communication, calculation, and all things electrical have not been the same since. The first highfrequency transistor was the surfacebarrier germanium transistor developed by philco in 1953, capable of operating up to 60 mhz. Ck722 ck721 ssa480 2sc912 sa52b sa537 2sc621 2sa525 2n3400 text. If it helps to you, i need them for a pacemaker, this one. The transistor is the fundamental building block of both digital and analog integrated circuitsthe circuitry that governs the operation of computers, cellular phones, and all other modern electronics. As i stated above, just about any pnpge transistor will work in place of the ck722, as they are all better transistors. A voltage or current applied to one pair of the transistors terminals controls the current through another pair of terminals. This article is not only interesting, but timely, because 1998 marks the 50th anniversary of the june 1948 public announcement of the transistor s invention. Tentative data on the raytheon ck722 germanium junction transistor.