JFET retro style regenerative receiver

Regenerative receiver with field effect transistors and variometer - variocoupler coil.
Band: AM MW.

[@coffeecuppepsi]

It amazes me all the devices you build. I haven't even made one functional device yet 😢

[@user-io3yy9vp9n]

Don't be afraid to experiment. Just buy a soldering iron and do it!😃

[@ingussilins6330]

Try made short wave regenerative receiver or VLF natural radio receiver.

[@vintagetransistorRadio.Radio.h]

I love Radio ❤

[@vintagetransistorRadio.Radio.h]

Nyc 😮😮😮

[@MAKSMIT-ME]

🙂👍

[@user-io3yy9vp9n]

Цікава схема. Але щось дуже тихо. Роздільний конденсатор і резистор зміщення в затворі другого транзистора можна видалити зі схеми. Буде працювати і без них.

[@ingussilins6330]

Сильних сигналів цього разу не було. Є трейлерне відео з цим приймачем і там звуки голосніше. Щоб видалити конденсатор зв’язку затвора та резистор другого транзистора, виміряйте напругу постійного струму на виході першого транзистора та перевірте, чи можете ви це зробити. Другий транзистор мав би збільшити стоковий резистор.

[@user-io3yy9vp9n]

@@ingussilins6330 так, це слушне зауваження. У моїх BF245 в такому включенні на витоку напруга 0,4в. Це означає, що на витоку другого транзистора напруга збільшиться на ті ж самі 0,4в що не є критичним. Якщо величину опору в витоку другого транзистора залишити незмінною, то це призведе до збільшення струму через його канал та трохи збільшить підсилення каскаду.

[@user-io3yy9vp9n]

@@ingussilins6330My BF245 has 0.4V at the source. KP303 is very similar in characteristics to these transistors. You have a resistance of 100 ohms at the source of the second transistor. At a voltage of 0.4V, the channel current should be about 4mA. If at its gate there is initially 0.4V, then at the source the voltage will increase to 0.8V and the channel current will be 8mA, which is not critical. But you can double the value of the source resistance so that the current remains approximately the same.

[@ingussilins6330]

@@user-io3yy9vp9n I measured voltage drop on first transistor's source resistor ( 10K ) and it is 633mV. Second's transistor's source resistor's ( 100 ohm ) voltage drop is a 346mV. I think theoretically can connect first transistor's source to second transistor's gate directly. ( 100 ohm resistor need replace with 330 ohm resistor. )

[@user-io3yy9vp9n]

@@ingussilins6330 it is really good idea.

[@laurinippon4655]

Jfet tipe ...???

[@ingussilins6330]

Yes, JFET field effect transistors.

[@8Ugri8]

You can create something from nothing!

[@ingussilins6330]

Thanks! ,today variable capacitors hard to get. From 1924 clever ideas to 2024 year. :)
Next level - homebrew Crystadine regenerative receiver ( receiver with homebrew semiconductors ).

[@user-io3yy9vp9n]

@@ingussilins6330 I saw good (four-section 2x140pF + 2x30pF for AM/FM superheterodyne radios) variable capacitors on Ali. They cost about 2-3USD apiece. Just please don't try to make homebrew semiconductors! This is immediately -100 to your reputation in the eyes of professionals. This is something like a coming out of a supporter of a flat Earth and perpetual motion machines using the energy of the “universal ether”.😜🙄

[@user-io3yy9vp9n]

@@ingussilins6330 I saw good variable capacitors on Ali. They have 4 sections (2x140pF + 2x30pF) and cost about 2-3USD per piece. And please don't homebrew semiconductors. You will spend too much effort, time and money, but you will never get an amplification device that works satisfactorily. It’s easier to make a somehow working vacuum triode at home than even the worst tunnel diode. Of course, "cristadine" was invented 100 years ago. But still, it was obtained in laboratory conditions, and not in a home workshop. A home workshop cannot compare with a scientific laboratory, even if they are separated by 100 years. 😉