The CV-pin version worked slightly better, but it was still just barely possible to distinguish a voice over a standard commercial AM/FM receiver. One uses the control voltage pin to input the audio signal, while the other uses the reset pin. Around these parts, the venerable 555 timer is always brought up whenever things get to oscillating so you’ll no doubt be happy to see decided to give it a shot for his first experiments, testing two popular 555 transmitter circuits. does exactly this in the video after the break, building both a transmitter and receiver.Īt the most basic level, AM radio works by generating a carrier wave with an oscillator, and then modulating the amplitude with an audio signal. 100dollarhacker has updated the log for Atomic Force Microscope - from ground up.AM radios are relatively simple devices, and building one is a good way to start exploring the world of radio communications.Kris liked Embedding a mesh into 3D print.FutureTEK99 liked ZeroBot - Raspberry Pi Zero FPV Robot.SaratogaJerry liked RCBUS to USB Adapter.SaratogaJerry liked Building a 22MHz Z80 Computer in 4 Stages.SaratogaJerry liked Studio 68: a board for "retro experiments".samm928 has updated the project titled 21 Band Audio Spectrum Analyzer.volcomafk liked Wi-Fi informer "Magic Brick".Kelly on Modern Spark Gap Transmitter Uses A Rotary Gap.JRD on Hackaday Links: December 17, 2023. Joshua on Second Life UPS Mark II: A UPS For Low-Voltage DC Applications. jenningsthecat on Take The Minimal Pain Out Of ESP32 Programming.Lr0dy on Second Life UPS Mark II: A UPS For Low-Voltage DC Applications.The Commenter Formerly Known As Ren on Hackaday Links: December 17, 2023.Antron Argaiv on Calculation Before We Went Digital.Miles on The Dark Side Of Hacking XMas Lights, Literally.Sean on The Hot Chocolate Effect Explained.The Commenter Formerly Known As Ren on Take The Minimal Pain Out Of ESP32 Programming.Hacker Tactic: Internal ESD Diode Probing 12 Comments Can’t tell with this one, I won’t watch videos to see a schematic. I’d point to his work before some random project on the web, especially when many such circuits these days derive from his work. (He did the same, to a lesser extent, for superregenerative receivers, which are just an extension of the regen.). Over twenty years ago, Charles Kitchin went back and reviewed early literature on the regen, and then moved forward with various regen projects. Add some voltage regulation, you would if it’s an oscillator. Helps keep the regen from becoming unstable as the antenna waves in tye wind. So you can do things like add a stage between the antenna and set ctor, for isolation. But solid state made things small, and cheap. In the 1920s, parts were big, and expensive, hence simplicity reigned. When oscillating, it’s really the same concept as a direct conversion receiver. You needed that if receiving morse code, the oscillation beating the incoming signal down to audio. Posted in Radio Hacks Tagged radio, regenerative radio Post navigationĪctually, when regens were king, kicking them into oscillation was often important. The inventor, Edwin Armstrong, developed quite a bit of radio tech that we still use today. While regenerative receivers aren’t the most common architecture today, they still have their place. But, then again, we have a lot of partial projects like that gathering dust on the shelf, so maybe that’s not such a great idea. We’d be tempted to make a module out of the audio amplifier and then keep the RF section intact. We were a little sad to find out there was a plan to tear the radio down to build something else. This provides extremely high gain at a particular frequency which allows just a single stage to really pull in signals. Regenerative receivers work by holding an amplifier just shy of oscillating at a certain frequency. The layout would work with a single-sided PCB and would be a great board to produce by hand if you were inclined to develop that skill. The coil of #22 wire dominates the visual layout, and we imagine winding it might have been the most time-consuming part of the project. You can watch a video about the simple receiver - which looks good on a neatly done universal board - below. Well, one transistor if you don’t count the dozens that are probably on the audio amplifier IC, but we won’t quibble. Example? modified a few existing designs and built a one-transistor receiver. They perform well and they are dead simple to create.
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