What will power the next electronics revolution? | World ...

The first concerns silicon's poor electron hole mobility. A small amount of germanium is already added to improve this, but using large amounts or even a move to all-germanium transistors would be better still. Germanium was the first material used for semiconductor devices, so really this is a "back to the future" move. But re-aligning ...

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Tables of equivalents between russian and western parts

Very old general-use p-n-p germanium transistor. Can't find, sorry. GT311: Old, but still good germanium n-p-n device for working with frequencies up to 800 MHz. Can't find, sorry. KT315: general use n-p-n silicon transistor, an old design: BC146, GT402: low-frequency germanium p-n-p transistor, old design: Do not know* GT404: complementary ...

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Redesign Germanium Transistor Circuits, Part 3

Redesign Germanium Transistor Circuits, Part 3; Necessary Circuit Changes. Germanium-to-silicon conversion. Left: Original circuit from Chapter 4. Middle: Silicon, fixed-bias version. Right: Silicon, self-bias version (much stabler). The drawings also show how to convert from PNP to NPN transistors: Reverse all polarized parts.

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Redesign Germanium Transistor Circuits, Part 2

Redesign Germanium Transistor Circuits, Part 2; Conversion Examples. Bias Network, Etc. Below are several examples of the conversion process. I've analyzed a famous germanium project book and come up with substitutions for base bias resistors and other parts. The silicon replacements require twice the base bias voltage of germanium parts.

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Replacing Germanium Transistors - Antique Radio Forums

Additionally, Germanium transistors usually didn't have as much gain as was needed/wanted, leading to circuit design decisions that would be considered really bad today. Germanium circuits are often overly sensitive to Hfe/beta by modern standards. If you are going to mess around with Germanium, build a test fixture like this one.

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Germanium Transistors - ramblefx

Most germanium transistor production ceased in the 1970s in favor of silicon which are more stable, consistent, have higher gain, and lower leakage. 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.

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Germanium transistors: logic circuits in the IBM 1401 ...

This circuit uses an additional transistor and diode to shift the voltage levels. This was practical in an integrated circuit because the additional components had minimal cost. This circuit wouldn't have worked well in the IBM 1401 because the 1401's germanium components provided a much smaller voltage shift than the silicon components in the ...

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Substituting Silicon transistors for Germanium | All About ...

I was wondering if anyone could help me locate a way to find substitutions for the following germanium transistors. I'd like to convert a circuit to silicon if possible. I have SK3009, 2N2428 and 2N2431 transistors. Any help would be appreciated. Thanks.

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TRANSISTOR MUSEUM™ HISTORY OF

the use of germanium for diodes, with the introduction in 1946 of the 1N34 – the first commercial germanium crystal diode. Volume 1 of The History of Crystal Diodes includes historic examples of three germanium crystal diode types which are similar in performance and construction to the original 1N34. Below is a summary of the included diodes:

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The VOX Showroom - The V301H "California" Continental Tone ...

In their 1965/66 redesign of the Continental, Thomas Organ had the benefit of the new technology of silicon transistors. Silicon transistors were much more stable than germanium, and rarely needed replacement. Thomas Organ eliminated all of the germanium transistors from the British circuit in the new US design. The stability of the silicon ...

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THE 1960 ERA GERMANIUM ELECTRONIC DYNAMO …

transistor. This makes germanium power transistors very attractive for low voltage high current switching applications. In fact two germanium power transistors were used virtually universally in the 1960's for DC/DC converter applications such as 12V DC to 400V DC in a push-pull self oscillating circuit called a Royer Oscillator.

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Transistor Manual Third Edition ECG-315 - VTDA

Germanium and Silicon . ... transistor in a circuit as in Figure . EMITTER JUNCTION N EMITTER COLLECTOR JUNCTION + BA SE COLLECTOR FIGURE 6 Here we see that the emitter junction will pass current easily, because it has a forward bias. The collector junction however, will not pass current from the collector to base,

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What is the difference between a Wurlitzer 140 or 140b and ...

Likewise, germanium transistors are no longer made, and NOS transistors are becoming increasingly hard to find. It is often possible to replace germanium transistors with new silicon transistors, but the circuit will need to be re-biased (and, obviously, you will lose that unique germanium tone).

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Vintage Radio and Electronics. Germanium Transistors

GERMANIUM TRANSISTORS The following table lists the parameters for Germanium transistors. The column marked Case is the outline of the transistor case. Note: Not all headings are the same parameter. The case drawings are shown at the bottom of the page. Cases GEC MAZDA STC AEI HIVAC NEWMARKET TEXAS Transistors

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Silicon-Germanium Devices and Circuits for High ...

2.2 Printed Circuit Board (PCB) Approach 10 2.3 Dual-Inline Package (DIP) Approach 13 2.4 Reusable Fixture Design 14 2.5 System Bandwidth Limitations 15 2.6 Summary 16 III Device Characterization 18 3.1 Introduction 18 3.2 SiGe Heterojunction Bipolar Transistors (HBTs) 19 3.3 MOSFETs 25 3.4 Resistors 30 IV Bandgap-Based Circuits 32

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Germanium and Silicon in Fuzz – What's the Difference ...

The Germanium Transistor. The germanium transistor was the first to be mass-produced and made commercially available to the public. This transistor was used extensively in radio technology, helping to create the first portable AM radios, as well as the first car radios. It was even used in a few of the first guitar effect pedals in the 1960s.

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Transistor Circuit Handbook for the Hobbyist: 30 Useful ...

TRANSISTOR CIRCUIT FOR THE HOBBYIST . SYLVANIA LITHO U S.A. At last! a handbook that helps you learn transistor circuitry while building useful equipment at a sav- ing—Features circuits for ... PNP, NPN, receiver,projects, germanium Created Date: 2/11/2012 9:35:59 PM ...

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Germanium Can Take Transistors Where Silicon Can't - IEEE ...

That list includes carbon-nanotube transistors, vertically oriented switches, 3D circuits, channels made from a mix of germanium and tin, and transistors that …

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Bones Hi - Fi: Germanium Transistor Based Audio Power ...

The inherently widely varying parameters in germanium transistors means resistor values selected for AC / DC biasing, Q-point operation, feedback and stability that works for one circuit may not necessarily work in another similarly designed circuit even though both use germanium transistors from the same batch.

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MULLARD TRANSISTOR CIRCUITS - World Radio History

Bistable circuit using p -n -p and n -p -n combination Triggered blocking oscillator Free -running blocking oscillator (frequency divider) Self -gating Miller circuit.. Directly coupled d.c. amplifier for germanium transistors Directly coupled d.c. amplifier for silicon transistors.. Long -tailed -pair d.c. amplifier for germanium transistors

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Redesign Germanium Transistor Circuits, Part 7 ...

Redesign Germanium Transistor Circuits, Part 7 Replacement Transistors, Capacitors, & Diodes Universal Replacement Parts. Fortunately, replacing germanium devices with silicon ones isn't entirely guesswork. When the industry switched over in the 1960s and 1970s, it …

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Redesign Germanium Transistor Circuits, Part 1

Redesign Germanium Transistor Circuits, Part 1; Today... Build Germanium Transistor Projects with Silicon Transistors! 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. In the Seventies, the higher-grade silicon devices began to take ...

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Germanium transistors: logic circuits in the IBM 1401 computer

The wafer-based mesa transistor was invented in 1958, followed by the modern planar transistor in 1959. Thus, transistors were undergoing radical changes in the 1950s and IBM introduced new logic families to take advantage of these new transistor types. Conclusion. Diode-transistor logic was a key part of IBM's early computers such as the IBM 1401.

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Si Diode vs Ge Diode: Parameters and Uses Comparison

Therefore, in some specific environments, such as small signal detection circuits, germanium tubes are better. 1.2 Differences between Ge and Si Transistor The main difference is that the junction voltage drop is different, the forward voltage drop of the germanium tube is lower about 0.3V, and the silicon tube is higher about 0.7V.

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Germanium Transistor Amplifier Circuit – Electronics ...

Electronics Projects, Germanium Transistor Amplifier Circuit "audio amplifier circuits, transistor amplifier, " Date 2016/04/22. Once AD161-AD162 I had an experiment with pair. I still use almost every day. At first I didn't like the sound, but I like listening to. The frequency of particular speech sounds very clear and is understandable.

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Build this 8 Transistor Stereo Amplifier

The original circuit design for the Stereo Amplifier from Radio Shack used 8 germanium transistors arranged in three stages: Differential Amplifier, CE Driver, and Push-Pull Output. These stages were common in high-end commercial amplifier design so the 8 Transistor Stereo Amplifier project should have earned a lot of fans back then.

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Germanium: Semiconductor milestone -- ScienceDaily

Germanium is one material being considered to replace silicon because it could enable the industry to make smaller transistors and more compact integrated circuits, Ye said.

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The future of germanium ? ( diodes mainly ) | Electronics ...

about the future of germanium. Specifically, germanium diodes, as I have decided to possibly take to market some of my old circuit designs that used germanium diodes. There would seem to be a number of semi-houses that still manufacture them, however they certainly don't seem

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Comparison of Germanium Bipolar Junction Transistor …

COMPARISON OF GERMANIUM BIPOLAR JUNCTION TRANSISTOR MODELS FOR REAL-TIME CIRCUIT SIMULATION Ben Holmes Sonic Arts Research Centre, School of Electronics, Electrical Engineering and Computer Science Belfast, U.K [email protected] Martin Holters Department for Signal Processing and Communications, Helmut Schmidt University Hamburg, Germany

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silicon vs germanium | Electronics Forums

Germanium transistors have many of the. characteristics as silicon of the same size except they are very leaky. and continue to increase in leakage with time and temperature. Both. silicon and germanium have about a -2mv/c Vbe temperature coefficient. it just starts at 0.6v for silicon and 0.15v for germanium.

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Germanium transistors | Electronics Forum (Circuits ...

The specifications for germanium transistors are very poor compared to modern silicon transistors. The only reason to use germanium parts is repairing/restoring equipment that was designed for them. I got a big batch a couple of years ago to repair a part of an old Eastern European machine; I was intending to replace all the transistors in the ...

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Radio Circuits | Practical Analog Semiconductor Circuits ...

The circuit in the figure below adds an audio amplifier to the crystal detector for greater headphone volume. The original circuit used a germanium diode and transistor. A schottky diode may be substituted for the germanium diode. A silicon transistor may be used if the base-bias resistor is changed according to the table.

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General Electric Transistor Manual

The silicon unijunction transistor was originally known as a double base diode. It is similar to the germanium version of the unijunction transistor but differs quantita-tively in its characteristics. The transistor shown in Figure 7 consists of an N type silicon bar with ohmic BASE 2 P-N JUNCTION EMITTER OHMIC CONTACT VOLTAGE GRAINENT — --+10V.

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Reflex Receivers

The original designs with germanium transistors simply grounded the emitter due to the lower available gain. The second transistor acts like an emitter-follower at the RF frequency providing a low impedance RF source for the detector diode. ... The 1mH in the collector of the first transistor is optional in both circuits; it gives a little more ...

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GERMANIUM TRANSISTOR AMPLIFIER ... - circuit-diagramz.com

GERMANIUM TRANSISTOR AMPLIFIER AD161 AD162 SCHEMATIC CIRCUIT DIAGRAM. It was once an experiment with the AD161-AD162 pair. I still use it almost every day. At first, I did not like the voice very much but I enjoyed it as I listened. Especially the frequency at which speech sounds are very clear and understandable.

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One Transistor Radio - Peter Vis

In electronic engineering it is good practice to build circuits in logical stages and testing each stage before moving further. The first step of this project is to build the Crystal Radio -- Budget Cuts 140-pF, which will involve building the ferrite rod coil, selecting the tuning capacitor, using a suitable germanium diode, and establishing proper earth and antenna.

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3 Transistor Short Wave Radio

Simulation and prototype construction revealed that the updated circuit with 2N3904 transistors worked slightly better than the expected performance of germanium transistors in the original circuit. The next step was to confirm that the 2N3904 could also be used …

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magnavox driver transistor? - Antique Radio Forums

Using a silicon transistor in a circuit designed for germanium will be a problem without extensive redesign of the circuit. The voltages in the preamp and driver circuits are too low to damage the transistors so I doubt that there was anything that caused a transistor failure.

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Germanium Fuzz — BENSON AMPS

The low input impedance of the classic two transistor germanium fuzz circuit is both a blessing and a curse….a blessing because it can yield a tight sparkly clean tone when guitar volume is rolled down, and a curse because it sounds nasty (in a bad way) if there are buffers or pedals before it in a signal chain.

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