This is a variation of the the Electron Coupled Oscillator circuit, pioneered by Dow in 1931. Dow`s ECO has the screen `grounded` for RF. In this circuit, because I am using filament-type tubes instead of heater-cathode types, and because I didn`t want to build or use a pair of filament chokes with this first
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attempt, I chose to use the "cathodes" as the "grounded" or "common" electrode. I am hoping that it otherwise works much the same way as the standard ECO: i. e. , the cathode-grid-screen are the oscillator section, with the screen acting as the oscillator`s plate, and the plate of the tube and its associated tuned circuit making up the amplifier section of the transmitter. So, essentially, we have two tubes performing the work of four. Should be interesting. This circuit uses grid-block keying, and all components, with the exception of the values of tuned circuit components, are shown on the schematic. Plate voltage should be about 1500 VDC, screen voltage should be 300 - 500 VDC, suppressor voltage should be about 40 VDC, and bias (actually blocking bias) should be about -150 VDC. Power input should not exceed about 150 watts. Adjust voltages and loading for best keying. It might be better to use a push-pull grid/parallel plate (push-push) circuit, as suggested by one of the members of the GB list. The plate circuit would then be tuned to twice the grid circuit frequency. This should provide much better stability, and eliminate any parasitics or need for neutralization. Experimentation is in order. For any of these oscillator circuits which use tetrodes or pentodes, be sure to never apply screen voltage before applying plate voltage. Otherwise the screens may disappear in a blinding flash of light. This circuit should feed...
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....
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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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