as a PDF
... Since double tuning band-pass filter enjoys broad frequency bandwidth, good selectivity, and low sensitivity, it is widely used in practical engineering [1-3]. However, the filter coupled by inductance or capacitance isn’t easy to be integrated and it has been restricted in high frequency system. No ...
... Since double tuning band-pass filter enjoys broad frequency bandwidth, good selectivity, and low sensitivity, it is widely used in practical engineering [1-3]. However, the filter coupled by inductance or capacitance isn’t easy to be integrated and it has been restricted in high frequency system. No ...
safety and measurements in practice
... The evaluation of the results of the Line and Loop impedance and its comparision is very important to evaluate the way of troubleshooting: comparing the result of Line impedance and Loop impedance with other circuit’s results can tell us the possible type of the installation - if the Line impedance ...
... The evaluation of the results of the Line and Loop impedance and its comparision is very important to evaluate the way of troubleshooting: comparing the result of Line impedance and Loop impedance with other circuit’s results can tell us the possible type of the installation - if the Line impedance ...
Document
... If all three particles have the same mass and charges of equal magnitude, which is moving the fastest? ...
... If all three particles have the same mass and charges of equal magnitude, which is moving the fastest? ...
17227 2 - SK Engineering Academy
... of a power system. The grading is not possible to be achieved in long and thin networks and also it can be noticed that grading of settings may lead to longer tripping times closer to the sources, which are not always desired. These problems have given way to the concept of ‘unit protection’ where t ...
... of a power system. The grading is not possible to be achieved in long and thin networks and also it can be noticed that grading of settings may lead to longer tripping times closer to the sources, which are not always desired. These problems have given way to the concept of ‘unit protection’ where t ...
switching amplifier
... – Pulling, or rubbering capacitors are used to make fine adjustments to the crystal oscillator frequency. – Field-effect transistors (FETs) make good crystal oscillators. The Pierce oscillator is a common configuration that uses a FET. – An overtone crystal is cut so that it optimizes its oscillatio ...
... – Pulling, or rubbering capacitors are used to make fine adjustments to the crystal oscillator frequency. – Field-effect transistors (FETs) make good crystal oscillators. The Pierce oscillator is a common configuration that uses a FET. – An overtone crystal is cut so that it optimizes its oscillatio ...
Construction Guide of TH300S
... system – ham band and general coverage band. A doubly balanced diode ring mixer is used at the front end, offering good performance. 4 diodes are use for the product detector to handle strong signals and offer low noise. Ham Band B1: 7.000 – 7.500 B2: 14.000 – 14.500 General Coverage Band (GENE) B1: ...
... system – ham band and general coverage band. A doubly balanced diode ring mixer is used at the front end, offering good performance. 4 diodes are use for the product detector to handle strong signals and offer low noise. Ham Band B1: 7.000 – 7.500 B2: 14.000 – 14.500 General Coverage Band (GENE) B1: ...
Crystal radio
A crystal radio receiver, also called a crystal set or cat's whisker receiver, is a very simple radio receiver, popular in the early days of radio. It needs no other power source but that received solely from the power of radio waves received by a wire antenna. It gets its name from its most important component, known as a crystal detector, originally made from a piece of crystalline mineral such as galena. This component is now called a diode.Crystal radios are the simplest type of radio receiver and can be made with a few inexpensive parts, such as a wire for an antenna, a coil of copper wire for adjustment, a capacitor, a crystal detector, and earphones. They are distinct from ordinary radios as they are passive receivers, while other radios use a separate source of electric power such as a battery or the mains power to amplify the weak radio signal so as to make it louder. Thus, crystal sets produce rather weak sound and must be listened to with sensitive earphones, and can only receive stations within a limited range.The rectifying property of crystals was discovered in 1874 by Karl Ferdinand Braun, and crystal detectors were developed and applied to radio receivers in 1904 by Jagadish Chandra Bose, G. W. Pickard and others.Crystal radios were the first widely used type of radio receiver, and the main type used during the wireless telegraphy era. Sold and homemade by the millions, the inexpensive and reliable crystal radio was a major driving force in the introduction of radio to the public, contributing to the development of radio as an entertainment medium around 1920.After about 1920, crystal sets were superseded by the first amplifying receivers, which used vacuum tubes (Audions), and became obsolete for commercial use. They, however, continued to be built by hobbyists, youth groups, and the Boy Scouts as a way of learning about the technology of radio. Today they are still sold as educational devices, and there are groups of enthusiasts devoted to their construction who hold competitions comparing the performance of their home-built designs.Crystal radios receive amplitude modulated (AM) signals, and can be designed to receive almost any radio frequency band, but most receive the AM broadcast band. A few receive shortwave bands, but strong signals are required. The first crystal sets received wireless telegraphy signals broadcast by spark-gap transmitters at frequencies as low as 20 kHz.