A copy from an old italian magazine of amatorial electronics, proposing an add-on for tube receivers. The add-on was a simple one-tube short-wave transmitter leveraging the same power supply already available in the receiver. This circuit fascinated me when I was just a teenager. I was quite a nerd when I was a teenager. Sure, besides being very c
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lever at school, I was into any sort of strange hobbies including electronics. My father was seemingly proud of this. Perhaps my mother was a bit concerned, instead. You know, a male teenager is rather expected to hang out with friends, seek a girlfriend, etc. The project reported in that old magazine fascinated me at that time, because I had a tube receiver at home, and I got a spare tube from another old receiver so I apparently had almost all the ingredients. The only missing piece was the plate RF choke, but I managed to build what at that time I presumed to be a good approximation of it. So I tried! But I was unsuccessful. The reason of that early insuccess was a fundamental lack of specific knowledge in RF electronics. I had no actual chance to spread RF in the air, despite the schematics and the components, because for instance I knew nothing about antennas, transmission lines, and impedance matching. I will always be grateful to the poor victim of these early and cruel experiments, namely, a 6V6 tube that has survived nevertheless. Vacuum tubes are generous and patient, they tolerate our mistakes, and this is the main reason why I keep loving them for my RF experiments, despite the dangerously high voltages required for operation. First serious attempt: one-tube tx using a Sovtek 6L6 WXT+ tetrode in a Hartley electron-coupled oscillator. Circuit schematics is missing, but it was very similar to the one I attempted...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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