Floating the grid above ground is bad for RF, and bad for arc protection. The control grid ground is also the single most critical connection for stability. The grid connection to ground should always be as wide and short as possible, and use as many pins as possible. The input and output circuit of a grounded grid amplifier are connected in series through the tube.
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Plate current is common through both cathode and anode, and only dc plate voltage is not. Back when we measured power as plate input power and not RF output power, the FCC even had a rule similar to this. The FCC wanted driver plate input power to be included as a full part of power amplifier plate input power. Thus kilowatt grounded-grid amplifiers, like the Heathkit SB220, when driven by 100-watt exciters could only run 900 watts input if the operator wished to comply with FCC rules. Probably based more on FCC conservatism than actual operation, a few widely accepted handbooks and authorities claim driver power adds to output power via feedthrough and is not accounted for in the metering system. Thinking unclearly, these books propose full driver power be deducted from output power when calculating efficiency. In actual operation, every single milliampere of anode current contributed by the exciter is fully accounted for in the plate current metering. The only thing not accounted for is a portion of the average cathode-to-grid voltage, which directly adds to the anode-cathode voltage during negative cathode swings. During positive cathode voltage excursions the gird is more negative compared to the cathode, so the tube cuts off. Since the tube is just "coasting" the positive cathode swing does not detract from effective operating anode voltage. This asymmetrical tube conduction causes the RF voltage between cathode and...
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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