X-rays occupy a band within the electromagnetic spectrum higher in frequency (between 0.10 and 10 nm wavelength) than ultraviolet radiation and lower in frequency than gamma rays (less than 10 pm wavelength). At such a high frequency, the amount of energy they carry is awesome. They pass with minimal loss through most substances and their […]
What you need to know about information theory
A lot of the testing and verification activities of EEs today centers on concepts having a theoretical basis in Claude Shannon’s (of Nyquist-Shannon renown) article titled, A Mathematical Theory of Communication, which appeared in 1948 in the Bell System Technical Journal. Shannon’s full treatise gets to be quite mathematical. Fortunately, some of the fundamental concepts […]
Understanding total harmonic distortion measurements
Most electronics engineers and technicians have a good understanding of total harmonic distortion (THD). But there are a few elusive details that come into play during THD measurements. THD is the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency. Properly speaking, the fundamental frequency is […]
User review: Connecting the Tektronix AFG 31000 AWG to the MDO3000 oscilloscope
The new Tektronix AFG 31000 Arbitrary Function Generator is noteworthy in that the Home screen, accessed by pressing the Home button on the front panel, permits the user to choose a Basic or Advanced mode. The Basic mode resembles a traditional AFG, with a library of internal waveforms and menus that permit the user to […]
Basics of signal jamming
Discussions of signal jamming were once largely confined to electronic warfare forums. But with the rise of autonomous vehicle technology, jamming has become a mainstream topic. It now pays to know a few basics about both the test setups necessary to gauge resistance to jamming techniques and the principles of signal propagation. Many of the […]
Measuring Ethernet and WiFi transmissions
The Ethernet computer networking protocol is used in local area networks, metropolitan area networks and wide area networks. While the term is often used to distinguish wired data transmissions from Wi-Fi, both use parallel protocol details, notably 48-bit MAC address and Ethernet frame format. Actually, Wi-Fi is Ethernet over a different medium. There are a […]
The difference between spontaneous emissions and stimulated emissions
The terms spontaneous emission and stimulated emission sometimes get confused. The term thermal emission sometimes gets thrown into the mix as well. Here are the basic definitions to help sort things out and the procedures for measuring these parameters. When we speak of spontaneous or stimulated emissions we are referring to atoms whose electrons are […]
The difference between attenuation in conductors and optical fibers
Electrical power moves through a conductor when opposing dc or ac voltages are applied at opposite ends. Charge carriers — free electrons or electron holes in semiconductors, ions in electrolytes – migrate toward the opposite poles. Metals, with abundant free electrons, have high conductivity. All conductors are partial insulators and all insulators are, to some […]
Cathode ray tube vs. flat screen displays in oscilloscopes
Prior to the digital revolution in electronic instrumentation, oscilloscopes displayed waveforms on cathode ray tube screens. Modern digital oscilloscopes universally have flat screens. The flat screen is light, thin, consumes far less energy, and is less expensive to manufacture. All agree that it is a great improvement. The one advantage of CRT technology is that […]
Mitigating ac motor-shaft voltage and bearing currents
Bearing problems are the greatest single contributing factor in motor failure. Often motor damage happens before bearing wear is noticeable. To avoid expensive repairs and costly downtime, early detection is essential. Proper installation of replacement bearings and correct lubrication are critical. It is well known that insufficient lubrication brings early bearing failure, but many maintenance […]
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