#Triode

[jelabs]

[takmiblog]

6J5

[yiyuanmachine]

Ultrasonic plastic welding machine factory, TEL/wechat/ whatsApp: + 8613620006372

[lindahall]

Edward Victor Appleton – Scientist of the Day

Edward Victor Appleton, an English physicist, was born Sep 6, 1892, in Bradford, West Riding, Yorkshire.

read more...

[boypussydilf]

the graybles eps r so funny just for cuber. if you thought adventure time slang was weird NOW wait until language has changed over ANOTHER thousand years. actually he might just be an alien idk.

[forgottenbones]

Why The First Computers Were Made Out Of Light Bulbs

[an-enigmatic-mind]

I think I've been picking up on the significance of line weight.

[hfhoangquan]

Bóng đèn cao tần đa dạng công suất - nguồn gốc xuất xứ chính hãng. Nhập khẩu trực tiếp tại Nhật Bản, Trung Quốc, Pháp...

[rfantennaindia]

schottky diode smd - PCB Antenna

A diode is a two-terminal electronic component that allows current to flow in one direction while blocking it in the other direction. It is a semiconductor device made up of a p-type material and an n-type material, which are joined together to form a p-n junction.

Diodes are commonly used in electronic circuits for a variety of purposes, such as rectification (converting AC to DC), voltage regulation, and signal modulation. They are also used in power supply circuits, lighting circuits, and electronic displays.

[cetaceous]

Philips TB 3/1000 Transmitting Triode in an Audiophile Power Amplifier image credits: ReinoutdV on the diyAudio Forums

[jelabs]

[takmiblog]

6J5

[yiyuanmachine]

15khz 2600w Hollow plate corrugated ultrasonic welding machine for plastic turnover box

[senkusphone]

@aresagainstthemachine asked so this one is for you. Video of it working at the end.

Here's the one project I am so proud of I named my entire blog after it.

Back in 2020, while I was stuck at home with few pleasant things to do, I decided to bring this contraption to life.

Only recently had I gotten into this inspiring series called Dr. Stone, and when I saw them make this device in the anime, I knew it was my divine calling to build it, for I had prior experience building circuits with vacuum tubes, an interest that was fostered greatly by my late grandfather when I was a boy. It had been because of the stories he'd tell me that I built my first crystal radio back then (which took me about 4 years of trial and error). Now, people had ''built'' the phone on youtube at least once before, but I was not satisfied with what they did, when they used parts that were too advanced and didn't even get it to transmit a voice, only to pick up radio stations. So I tried to go beyond while being as accurate as possible to the level of technology they had, I was seeking to achieve more with less

Making something that picks a radio signal is relatively easy, the challenge was making it also produce its own signal so it could truly be used as a phone (or more accurately, like a walkie talkie), and I restricted myself to use the most primitive tubes I had, the ones most similar to what old Kaseki would have made.

(Happy birthday to Kaseki by the way, February 9th) I started out using this beautiful Western Electric 262-A tube. This general purpose triode was developed around 1928 by the Bell Telephone company and one of the things it was known to be used for, was in cinema projectors to amplify the sound from the early talkie films. I think that's interesting enough to mention.

It wasn't long until my experiments showed great promise, eventually I moved on to a type 45 vacuum tube, another triode which is more powerful as a transmitter than the 262-A yet its construction is much more primitive. This tube is very similar to what Senku & Co. would've had.

I started building the definitive device, simultaneously laying a plan to combine a transmitter and receiver in the same unit using just one tube, a task that required this one part to perform four different duties (because I hadn't read the manga, and I didn't know the final unit they dispatched used two tubes instead of just one). On new year's eve at the end of 2020, the circuit was broadcasting One Small Step by Lillian Weinberg, loud and clear to a radio across the room.

You can get a recording of that in the link below as Tumblr won't let me upload it (yes I am using discord to host files, it also works for hosting images for your fanfics on Ao3, you're welcome).

The wooden circuit board was wired with homemade wires, made by cutting a sheet of copper into strips, and wrapping them in cotton and thread. A relay is used to switch the phone from receiver mode to transmitter mode with the push of a button.

Then the coils were calculated and wound, including the iconic large transmit coil

but would this coil that was made to look like the one in the series, be suitable to repeat what I had achieved in my experiments, would it resonate and produce the signal?

yes

I intended originally to have this project done before season 2 of Dr. Stone started, and put out a youtube video, but that ended up not happening. Still, the unit finally came together, and the plastic housing was a tupper with the rim cut off, painted orange and applied lettering.

By now season 2 had already ended, I believe, or it was soon to. Before I painted the case, I had to have one definitive test, to see that my creation demonstrated the functionality it promised, and now I had just the right voice to do it.

The final circuit was based on the work of radio pioneer Edwin Howard Armstrong, who was one of the fellows who invented the wireless world we know it today.

I turned the switch, and watched as the tungsten filament in the tube started glowing red. First I adjusted the receive coil and a radio station came in on the crystal earpiece, then, with a radio receiver in tune nearby, I started the sound I wanted to send over the air, and I pressed the transmit button...

It's true, it can be done. Today, there are people still alive who saw the day when the cutting edge of electronics was at this level. How far we've come from these baby steps, over such a short time.

Isn't science awesome?

I still haven't built a second unit.

[audio-luddite]

More info on Old Tube Stuff.

I found the company that makes an "updated" Harman Kardon Citation 2. They now call it the "Citation Sound -2". The marketing docs claim it is just like the old HK, but no it aint. Not even close. And they dont make it. A Chinese company called CAYIN is the builder. VAS is the importer to the US.

Funny a company that lies in its marketing.

https://vasnyinc.com/

I will not dispute if it has good quality components and all that. But it is evident it does not use the HK circuit as designed by Stu Hegeman. The VAS unit has two triodes in front of the power tubes. Clearly labeled as the venerable 12ax7 and 12au7 double triode tubes. Looks so generic like a Dynaco MkIII*. The HK has three tubes in front.

Not Triodes, but Pentodes and called out as 12BY7a. Hey whats a few letters here and there. They are available so they could have made a proper version. Copyrights do not last forever. But more complex designs are more expensive gotta watch the pennies.

So no it aint a Citation 2 even a little bit. Current prices for a real one are around $2500 USD and less.

With that schematic and three transformers I could build one.

But as the French Knight in Monty Python's Holy Grail said, "I've already got one". (as in a 60 Watt per channel tube amp of pedigree).

*PS The Dynaco MK3 had a combination pentode/triode input tube ahead of the power tubes. On that basis it was more sophisticated 60 years ago than this Chinese amp today.

[materialsscienceandengineering]

Gate-tunable heterojunction tunnel triodes based on 2D metal selenide and 3D silicon

Electronics engineers worldwide are trying to improve the performance of devices, while also lowering their power consumption. Tunnel field-effect transistors (TFETs), an experimental class of transistors with a unique switching mechanism, could be a particularly promising solution for developing low-power electronics.

Despite their potential, most TFETs based on silicon and III-V heterojunctions exhibit low on-current densities and on/off current ratios in some modes of operation. Fabricating these transistors using 2D materials could help to improve electrostatic control, potentially increasing their on-current densities and on/off ratios.

Researchers at University of Pennsylvania, the Chinese Academy of Sciences, the National Institute of Standards and Technology, and the Air Force Research Laboratory have recently developed new heterojunction tunnel triodes based on van der Waals heterostructures formed from 2D metal selenide and 3D silicon. These triodes, presented in a paper published in Nature Electronics, could outperform other TFETs presented in the past in terms of on-current densities and on/off ratios.

Read more.