![How to Find Ground Loops and Prevent AC Hum](http://s1.studyres.com/store/data/006293148_1-3abf6a7afd2857a08b52a221545515c5-300x300.png)
How to Find Ground Loops and Prevent AC Hum
... When you hear hum in an audio system, it's almost always caused by a loop antenna effect between two or more pieces of gear, across signal lines. A loop antenna is formed by having a loop of wire where the beginning and end of the loop are connected - the loop can be any shape. The loop antenna(e) i ...
... When you hear hum in an audio system, it's almost always caused by a loop antenna effect between two or more pieces of gear, across signal lines. A loop antenna is formed by having a loop of wire where the beginning and end of the loop are connected - the loop can be any shape. The loop antenna(e) i ...
4-Stage
... 1. Set jumpers to desired position as follows: • Mode jumpers (H1, H2) - In FLT position, the A and D relays energize on a decrease in signal. In the SEQ position, the A and D relays energize on an increase in signal. The B and C relays always energize on an increase in signal. • Input jumpers (H3, ...
... 1. Set jumpers to desired position as follows: • Mode jumpers (H1, H2) - In FLT position, the A and D relays energize on a decrease in signal. In the SEQ position, the A and D relays energize on an increase in signal. The B and C relays always energize on an increase in signal. • Input jumpers (H3, ...
RECOMMENDATION ITU-R F.760-1 - Protection of terrestrial line
... Next, off-beam interference is considered. The aggregate of interference from all sources is mitigated by the receive antenna discrimination. A similar relationship between angle of arrival and angle of elevation is assumed as in setting the pfd limits for sharing with the fixed-satellite service in ...
... Next, off-beam interference is considered. The aggregate of interference from all sources is mitigated by the receive antenna discrimination. A similar relationship between angle of arrival and angle of elevation is assumed as in setting the pfd limits for sharing with the fixed-satellite service in ...
Slides - GSI Indico
... SiPMs at the border of the cluster receive a small total number of photons, distributed in time according to the time constant of the scintillator The related current signal can be under the threshold set on the current level, thus these detectors would be ignored in a sparse read-out acquisitio ...
... SiPMs at the border of the cluster receive a small total number of photons, distributed in time according to the time constant of the scintillator The related current signal can be under the threshold set on the current level, thus these detectors would be ignored in a sparse read-out acquisitio ...
Interface Changes of Second Generation 1775
... The 17XX IMUs and DSP-1760 gyro units use typical RS-422 receiver devices to convert the differential inputs to single-ended signals that are then used internally. Different inputs may use physically different receiver or transceiver devices, but they all operate in a similar way. In the schematic r ...
... The 17XX IMUs and DSP-1760 gyro units use typical RS-422 receiver devices to convert the differential inputs to single-ended signals that are then used internally. Different inputs may use physically different receiver or transceiver devices, but they all operate in a similar way. In the schematic r ...
Moving coil meters for DC measurements
... Frequency is the number of cycles per second. It is measured in hertz (Hz), but frequencies tend to be high so kilohertz (kHz) and megahertz (MHz) are often used. 1kHz = 1000Hz and 1MHz = 1000000Hz. ...
... Frequency is the number of cycles per second. It is measured in hertz (Hz), but frequencies tend to be high so kilohertz (kHz) and megahertz (MHz) are often used. 1kHz = 1000Hz and 1MHz = 1000000Hz. ...
Recommended Levels of Digital Signals Relative to Analog
... The recommended QAM level is determined by first assuming that it is desirable to set it equal to the average power of an analog video signal. However, even when this is done, the two signals will have significantly different amplitude distributions; that is to say, the probability of measuring any ...
... The recommended QAM level is determined by first assuming that it is desirable to set it equal to the average power of an analog video signal. However, even when this is done, the two signals will have significantly different amplitude distributions; that is to say, the probability of measuring any ...
Sampling: DAC and ADC conversion
... noise is present in the analog signal (2) The quantization error is determined by the number of bits that are later used to encode the signal. If we increase the number of bits, the error will decrease Question: How many bits do we need in the ADC? How fine should the quantization be? (equivalent qu ...
... noise is present in the analog signal (2) The quantization error is determined by the number of bits that are later used to encode the signal. If we increase the number of bits, the error will decrease Question: How many bits do we need in the ADC? How fine should the quantization be? (equivalent qu ...
P1.7.4.2 - LD Didactic
... Ultrasonic waves are reflected at the boundary surfaces between media with differing resistances to sound waves. An echo sounder (or “sonar”) device emits pulsed ultrasonic signals and measures the time in which a signal is reflected from such a boundary surface to the receiver. To simplify the conf ...
... Ultrasonic waves are reflected at the boundary surfaces between media with differing resistances to sound waves. An echo sounder (or “sonar”) device emits pulsed ultrasonic signals and measures the time in which a signal is reflected from such a boundary surface to the receiver. To simplify the conf ...
Using Oscilloscope
... Each of the two magnified modes—ALT or MAG—expands the unmagnified trace. When ALT is chosen, both the unmagnified and the magnified waveforms appear together on the crt screen. Vertical separation between them is adjusted with the TRACE SEP control. If MAG is selected, only the magnified trace is d ...
... Each of the two magnified modes—ALT or MAG—expands the unmagnified trace. When ALT is chosen, both the unmagnified and the magnified waveforms appear together on the crt screen. Vertical separation between them is adjusted with the TRACE SEP control. If MAG is selected, only the magnified trace is d ...
Dispersion in Optical Fibers
... this equation implies that at the point of zero dispersion, λD , where β̈ = 0 the group velocity, vg as a function of ω has a minimum (the derivative is zero). For wavelengths λ < λD , β̈ > 0 and the fiber is said to exhibit normal dispersion. In this regime (dvg /dω) < 0, which means high-frequency ...
... this equation implies that at the point of zero dispersion, λD , where β̈ = 0 the group velocity, vg as a function of ω has a minimum (the derivative is zero). For wavelengths λ < λD , β̈ > 0 and the fiber is said to exhibit normal dispersion. In this regime (dvg /dω) < 0, which means high-frequency ...
Inverting and non inverting amplifier
... Dept. of Electrical, Computer and Biomedical Engineering ...
... Dept. of Electrical, Computer and Biomedical Engineering ...
AM Principles_Lecture2
... • Low level AM produces the AM signal at a very low power level. High power amplifiers increase the power to the desired level. Less efficient linear amplifiers must be used to amplify the AM signal. • High level AM is produced by amplitude modulating the final amplifier stage in a transmitter. More ...
... • Low level AM produces the AM signal at a very low power level. High power amplifiers increase the power to the desired level. Less efficient linear amplifiers must be used to amplify the AM signal. • High level AM is produced by amplitude modulating the final amplifier stage in a transmitter. More ...
Lock-in amplifiers
... Sum and difference freq generated Compare to signal addition -- interference Signal frequency close to reference freq – low freq beat – DC for equal freq sine waves – DC output level depends on relative phase ...
... Sum and difference freq generated Compare to signal addition -- interference Signal frequency close to reference freq – low freq beat – DC for equal freq sine waves – DC output level depends on relative phase ...
High-frequency direction finding
![](https://commons.wikimedia.org/wiki/Special:FilePath/HMS_Belfast_-_Huff_Duff.jpg?width=300)
High-frequency direction finding, usually known by its abbreviation HF/DF or nickname huff-duff, is the common name for a type of radio direction finder (RDF) introduced in World War II. High frequency (HF) refers to a radio band that can efficiently communicate over long distances; for example, between U-boats and their land-based headquarters. HF/DF was primarily used to catch enemy radios while they transmitted, although it was also used to locate friendly aircraft as a navigation aid. The basic technique remains in use to this day as one of the fundamental disciplines of signals intelligence, although typically incorporated into a larger suite of radio systems and radars instead of being a stand-alone system.Huff-duff used a set of antennas to receive the same signal in slightly different locations or angles, and then used the slight differences in the signal to display the bearing to the transmitter on an oscilloscope display. Earlier systems used a mechanically rotated antenna (or solenoid) and an operator listening for peaks or nulls in the signal, which took considerable time to determine. Huff-duff's speed allowed it to catch fleeting signals, such as those from the U-boat fleet.The system was initially developed by Robert Watson-Watt starting in 1926, although many of the practical elements were not developed until the late 1930s. Huff-duff units were in very high demand, and there was considerable inter-service rivalry involved in their distribution. An early use was by the RAF Fighter Command as part of the Dowding system of interception control, while ground-based units were also widely used to collect information for the Admiralty to locate U-boats. Between 1942 and 1944, smaller units became widely available and were common fixtures on Royal Navy ships. It is estimated huff-duff contributed to 24% of all U-boats sunk during the war.The basic concept is also known by several alternate names, including Cathode-Ray Direction Finding (CRDF), Twin Path DF, and for its inventor, Watson-Watt DF or Adcock/Watson-Watt when the antenna is considered.