The best way to get a sense for space-charge tubes is to study some real circuits. Look at the online circuits listed below, and see if you (or one of your friends) have any of the older print articles listed after the online articles. That done, choose a simple circuit for a `learning project` and just have at it! That said, here are some tips: B
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e aware that these tubes (with the possible exception of the type 8056 nuvistor) draw a lotof current at 12V, sometimes almost half an amp. (Virtually all of this goes into heating the cathode. ) If you put three or four in a circuit, you had better be able to supply 12V at two or three amps. This is easy in a car; not always so easy on a test bench. I don`t recommend making up space-charge portable radios using AA cells! Avoid grid confusion! The first grid (the grid physically closest to the cathode; what in conventional tubing is called the control grid) should be tied to 12V. If you`re using a conventional tetrode or pentode in space-charge mode, make sure you put 12V on the control grid, and use the screen grid as the control grid. Pentode suppressor grids are almost always tied internally to the tube cathode, but if the suppressor grid comes out separately to a pin, try putting 12V on the suppressor as well. This may allow greater gain in some circuits, as you have two grids accelerating electrons toward the weakly charged plate. Biasing is not anything like biasing when your B+ is in the 150-200V range. Don`t just drop a 12V tetrode or pentode into a circuit designed for a 180V tubes. Try to find some of the articles I list below and study the circuits. It`s not that they`re more complex. (Generally, you`ll find them simpler!) They`re just different. If you possibly can, find a copy of an early 1960`s RCA receiving...
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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