This little project arose from a desire to experiment with some of the more `traditional` methods of radioconstruction which enjoyed popularity some 70 years ago. I wanted to find out for myself what kind of performance could be achieved using simple circuits incorporating Valves/Vacuum Tubes and low budget design techniques popular in the 1930`s.
Click here to download the full size of the above Circuit.
In particular I was curious to try out "Spider" coils and a Regenerative Detector using a low-mu (low gain) triode as the active device. There is a great deal of "folklore" surrounding regenerative receivers with claims of exceptionally good performance from these simple designs. For the most part these claims are well justified. Its true to say that a well constructed regen receiver of good design will give pleasing performance. Over the yearsa number of regen receivers have been constructed here at M0AYF for both broadcast and ham radio reception usingvacuum tubes and/or solid state devices. Icanconfirm that they do indeed perform as advertised. But most of the receiversbuilt herehad taken advantage of using modern components and construction techniques so it was interesting to build the "retro" receiver using more traditional construction techniques and then to compare the performance to that of newer designs. In order to remain as faithful as possible to the traditional methods of construction and technology available in the 1930`s it was decided that low-mu (low gain) triodes would be used for the various stages of the receiver. Though I have a small quantity of 1930`s triode valves/tubes in the M0AYF junk-box the decision was made to save these for a future "retro" project. So a suitableactive device to serve as a replacement for the low-mu triodes had to be found. Physical inspection of the internal construction of...
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.....
characters left: