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Grid dip oscillators were first developed in the 1920s and were built with vacuum tubes.The devices displayed the amplitude of the tube's grid current, hence GDO.. Modern dip meters are solid-state devices, and are sometimes called gate dip oscillators or emitter dip oscillators in reference to the analogous part of the transistor whose current is measured instead of a vacuum tube grid. [1]
A wavemeter consists of an adjustable resonant circuit calibrated in frequency, with a meter or other means to measure the voltage or current in the circuit. When adjusted to resonance with the unknown frequency, the resonant circuit absorbs energy, which is indicated by a dip on the meter. Then the frequency can be read from the dial.
The requirements of a flicker measurement equipment are defined in the international electro-technical standard IEC 61000-4-15. [2]A flickermeter is composed of several function blocks which simulate a 230 V/60 W or a 120 V/60 W incandescent lamp (reference lamp) and the human perception system (eye-brain model).
Later in the 1960s they made the EICO 753 SSB transceiver for amateur radio use. Unfortunately problems with the 753--or seven drifty three-- damaged their reputation which led to their decline. They also sold specialty test equipment for the ham radio market, including signal generators and grid dip oscillators. [3]
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Using a PMU, it is simple to detect abnormal waveform shapes. A waveform shape described mathematically is called a phasor.. A phasor measurement unit (PMU) is a device used to estimate the magnitude and phase angle of an electrical phasor quantity (such as voltage or current) in the electricity grid using a common time source for synchronization.
For evaluating the dip and dip directions of rock planes, digital terrain models should be used. The DTMs are classified by the basic geometric units, such as triangles, squares. 3 major mathematic functions are used, as listed below : Point-based [37] Triangular-based [37] Grid-based [37] Moreover, triangle-based and grid-based are the most used.
A grid dip oscillator (GDO) is sometimes used to help facilitate initial tuning and aid in design. The resonant frequency of the secondary can be difficult to determine except by using a GDO or other experimental method, whereas the physical properties of the primary more closely represent lumped approximations of RF tank design.