Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 22, 2025
Then set the variable condenser in front of it, set the vacuum tube detector at the right hand end of the tuning coil and the rheostat in front of the detector. Connecting Up the Parts.
A rheostat is also useful in that it keeps the filament from burning out when the current from the battery first flows through it. You can very often increase the sensitiveness of a vacuum tube after you have used it for a while by recharging the A or storage battery. The degree to which a vacuum tube has been exhausted has a very pronounced effect on its sensitivity.
Kendall turned over a small rheostat control and abruptly the eighteen-inch diameter spot on the tungsten-beryllium plate began contracting; it contracted till it was a blazing, sparkling spot of molten incandescence less than an inch across! "That's the advantage of focus. At this distance of a few hundred feet with a small beam I can do that.
While one of these sets costs more than you can assemble a set for yourself, still, especially in the beginning, it is a good plan to buy an assembled one for it is fitted with a panel on which the adjusting knobs of the rheostat, tuning coil and condenser are mounted and this makes it possible to operate it as soon as you get it home and without the slightest trouble on your part.
The apparatus you need for this set includes: a loose coupled tuning coil, a variable condenser, two fixed condensers, a crystal detector, or better a vacuum tube detector, an A or 6 volt storage battery, a rheostat, a B or 22-1/2 volt dry cell battery, a fixed resistance unit, or leak grid as it is called, and a pair of head-phones. The Vacuum Tube Amplifier.
A movable contact arm that slides over and presses on the turns of wire is fixed to the knob on top of the rheostat. A rheostat that has a resistance of 6 ohms and a current carrying capacity of 1.5 amperes which can be mounted on a panel board is the right kind to use. Assembling the Parts.
Now put the other foot on the rheostat and let the left elbow gently rest on the deodorizer. Keep the rubber tube connecting with the automatic fog whistle closely between the teeth and let the right elbow be in touch with the quadruplex while the apex of the left knee is pressed over the spark coil and the right ankle works the condenser." Uncle Gilbert grunted.
This done connect the other terminal of the filament to one post of the rheostat, the other post of this to the or negative electrode of the 6 volt A battery and the + or positive electrode of the latter to the other terminal of the filament.
There was a faint hum from the coil; then it was gone. There seemed to be no other result. He rotated it a bit more; a slight draught sprang up within the room. He waited, but when nothing more startling occurred, he gave the rheostat a sharp turn. This time there was absolutely no doubt as to the result.
He turned on the current from the small battery installed in it, then began talking at the same time he was turning a rheostat higher and higher. Finally he noticed those mobile ears began to twitch, and as he turned the tones higher and still higher, more and more of the natives stopped work and turned toward him.
Word Of The Day
Others Looking