Getting the frequencies right is also an imperative step in selecting to replace transistors. The new one should be either close or of a higher frequency limit than the original. However, avoid one with a very high frequency to avoid the possible risk of oscillation. A transistor will dissipate heat during operation.

Sep 6, 2009. #7. Hyperion said: You would probably have to change a few components around this transistor if you change it for a Silicon one - overall I think Avionic's suggestion is the best - put another Germanium one in. In applications where the noise factor of transistors is important, like preamp stages, the circuits are usually tolerant ...

ALSO BY THE SAME AUTHOR BP108 International Diode Equivalents Guide BP140 Digital IC Equivalents and Pin Connections BP141 Linear IC Equivalents and Pin Connections. INTERNATIONAL TRANSISTOR EQUIVALENTS GUIDE. by. ADRIAN MICHAELS BERNARD BABANI (publishing) LTD THE GRAMPIANS. SHEPHERDS BUSH ROAD.

Transistors based on germanium can be operated at low supply voltages and reduced power consumption, due to the low band gap compared to silicon. Additionally, the realized germanium based ...

The 121-352 is a PNP germanium transistor used in the intermediate frequency (IF) stages. This is a small-signal high frequency transistor. You can usually swap the three from the IF with the three for the AM section and the radio still works. AF116 also works in stage one and stage three of the IF circuits.

The use of germanium promises to eliminate some of the traps which cause generation-recombination noise in silicon field-effect transistors (FET's) at low temperatures. Typically, the transconductance (g{sub m}) in the germanium FET's is 10 mA/V and the gate leakage can be less than 10⁻¹² A.

Under Shockley's direction, John Bardeen and Walter Brattain demonstrated in 1947 the first semiconductor amplifier: the point-contact transistor, with two metal points in contact with a sliver of germanium. In 1948, Shockley invented the more robust junction transistor, built in 1951. The three shared the 1956 Nobel Prize in Physics for ...

New Germanium-Based Material Could Replace Silicon for Electronics. A half-century after it was supplanted by silicon, germanium may push silicon—and …

You cannot replace a Germanium transistor with a silicon transistor… without significantly redesigning the circuit. Germanium transistors come in PNP and …

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A transistor has three leads: source, gate and drain. To explain its operation, we will use a simple paradigm. Think of a pipe that connects a source of water …

We first examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured.

There is at least one silicon transistor that apparently will replace an AF117 usually without modification, the BF450. However that has now become expensive too. …

Material of Transistor: Ge Polarity: PNP Maximum Collector Power Dissipation (Pc): 0.083 W Maximum Collector-Base Voltage |Vcb|: 15 V Maximum Collector-Emitter Voltage |Vce|: 12 V Maximum Emitter-Base Voltage |Veb|: 12 V Maximum Collector Current |Ic max|: 0.01 A Max. Operating Junction Temperature (Tj): 80 °C Transition Frequency (ft): 8 MHz

This model of transistor is best known for it's use inside Kundo's line of electromagnetic pendulum clocks, which make use of the transistor in the pendulum drive circuit. The TF65 is a common point of failure in these clocks, requiring replacement with a more readily available germanium part number, the AC125 being the most common …

Figure I. A schematic of strained Si NMOS transistor with HfO2fTiN metal-gate stack 0-7803-8618-3/04/$20.00 02004 IEEE 194 Authorized licensed use limited to: Penn State University. Downloaded on November 14, 2009 at …

Distributor Cross Reference Search From this one search tool you can now find replacements for over 470,000 industry devices. Enter the part number you wish to replace and click the search button or press the ENTER key on your keyboard. You may use the * character as a wildcard, but you must supply at least two other characters.

Transistor Faults, Testing and Replacement. It is a common belief that valves are unreliable and that transistors last forever. In fact valves are nowhere near as unreliable as people think (repairers would often claim a valve had failed and charge for it to cover the cost of the time spent finding and replacing a couple of faulty capacitors ...

Also BC550/BC560. Both pairs have different gain codes so I can match almost all transistors from the amp. I'll list the transistors I found: Power Supply: H802 - 2sc945p (hfe 237) in the datasheet P is 200-400. H803 - …

Now researchers at Ohio State University (OSU) are bringing germanium back to electronics in a way that they believe could displace silicon. To achieve its new role the researchers have ...

1. Introduction. The motivation to replace strained silicon (Si) with higher mobility channel materials in today's metal-oxide-semiconductor field-effect transistors (MOSFETs) is well documented [1,2].Saturation drive current (I on), a critical performance metric for FET devices, is intimately linked with carrier mobility.While this link has …

Overview. The Chandler Limited Germanium Preamp / DI is a single channel mic preamplifier and direct interface using discrete circuitry with germanium transistors, emulating the sound of early transistor equipment which is known for its colorful sound. A "THICK" switch on the front panel provides a bass boost and extra harmonics.

Germanium Transistors There is an audible sound difference between germanium and silicone transistors (it appears that all together germanium devices have lower intermodulation distortion and this is giving "clean" sound similar to tube pre-amps). The best possible transistors for that purpose were AC151r and they were used in …

But adding germanium to the channel—even initially mixed in with silicon—is a solution that will allow chipmakers to keep improving transistors in the near term. Germanium, the primordial ...

As to your question, looking at fig 3, 4 and 5 on page 5 of the article, I think you could replace the PNP germanium transistors directly with a small silicon PNP …

We all (meaning experienced techs) know the difference between germanium and silicon, and if we can draw out the circuit, we can make whatever changes it might need. In the case of the power amp, if we didn't make the changes, we'd have audio distortion. In the case of a power supply transistor, distortion is not an issue.

But again, for fault finding you don't "check transistors", you fault find the circuit - measuring the voltages on all transistors would be the place to start. The entire power amp is a kind of 'opamp', with DC feedback - with the output at +30V the feedback should be turning the bottom output transistor ON to bring it down - the …

Chee-Wee Liu and colleagues at the National Taiwan University now report germanium-based eight-stack nanosheet and seven-stack nanowire gate-all-around transistors. The devices are fabricated ...

Thanks to Moore's Law, the transistor has delivered computers far beyond anything thought possible in the 1950s. Despite germanium's starring role in the transistor's early history, it was soon supplanted by silicon. But now, remarkably, the material is poised for a comeback. The world's leading-edge chipmakers are …

I suspect I will increase the supply to around 8 volts and replace the 3.3 ohm current source resistor with a 4.7 ohm. ... better check what other size cases are available lol Can't even use germanium for the switching transistor ... 12:26 pm #16 12:26 pm #16 The switching device in the above PSU is now an IFR630 Fet. …