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[AES/EBU]
Standardised, balanced digital interface with 110 Ohm
impedance cable.
[Attenuation]
The decrease of an electrical signal with the distance
in the direction of propagation. Attenuation may be expressed
as the scalar ratio of the input magnitude to the output magnitude
indB/m ordB/100m.
[Balanced
Line]
A signal and its mirror image are carried on a pair of
wires. Subtracting the signal from its mirror image cancels
out interference. Balanced cables are usually
screened, but the screen is not necessarily part of the signal
circuit. [see also ::: XLR]
[Bending
Radius]
The smallest bending radius, which can be allowed for
fixed installations [static radius] or flexible applications
[dynamic radius].
[BNC]
BNC stands for »Bayonet Navy Connector« or »Neil Concelman Connection« and
marks an international family of connectors for coaxial cables.
The BNC connector is designed for specific impedances and is
therefore an optimal match to the appropiate cables. BNC connectors
usually available as 50 or 75 Ohm types.
[Capacitance]
Electrical characteristic of cables or components based
on the storage of electrical charge.
[Characteristic
impedance]
See ::: Impedance
[Coaxial]
A cable consisting of an inner conductor, a tubular outer
conductor and an insulating material between the inner and
outer conductor [dielectric]. The outer conductor functions
as a screen.
[Coverage]
A calculated percentage which defines the degree to which
a braid or shield covers the surface of the underlying component.
[Crossover]
Generally a circuit which separates frequency bands in
order to send them to the appropriate circuits or loudspeaker
driver.
[Cut–off
frequency]
The highest frequency passed by a cable without damping.
The transmission characteristic of cables above their cut–off
frequency may be unstable.
[DA–Converter]
Device to convert a digital input [e.g. from a CD transport]
to a line level, analogue output. This can be either a separate
unit or integrated into a CD player.
[Dielectric]
A material which acts a an electrical insulator.
[Dielectric
Loss]
In a coaxial cable, the losses caused by the transformation
of electromagnetic energy into heat within the dielectric material.
[Dielectric
Loss Factor]
A measure of the loss characteristics of a dielectric
material.
[Eccentricity]
The measure of a conductors’ location with respect
to the geometrical centre of the insulation. Expressed as a
percentage of centre displacement of one circle within the
other.
[EMC,
EMI]
Terms defining the electromagnetic susceptibility of a
device against external electromagnetic fields, and the fields
radiated by the same device.
[Floating]
Circuit electrically isolated from ground and all other
circuits
[Grounding]
Connection of electrical circuits to a common zero volt
reference, usually mains supply earth or equipment casing and
cable screens
[Impedance]
Generally a combination of resistance and reactance [either
capacitive or inductive] which characterizes an electrical
component or device. In the context of cables and connections
the characteristic impedance is the load for a give transmission
line, for which no standing wave reflections occur and the
transferred power is a maximum.
[Insertion
Loss]
Power lost on the main line between source and load due
to reflection, dielectric and conductor losses.
[Jitter]
Short term instability of a signal [rising edge] relative
to time. For digital systems the crossing of the signal at
zero will be changed which causes distortion of pulsed signals.
[Load,
Loading]
Combination of resistance or reactance connected to the
output of as transducer or power source.
[Mating
cycle life]
Plugs can be used without degradation of performance for
a certain number of connect/disconnect cycles. After exceeding
this limit the overall performance of the cable/plug/socket
system changes. The mating cycle life also depends on the socket
condition; damaged sockets reduce the cycle life of a connector.
[Mismatch
Loss]
The loss of power delievered into a load as a result of
the interconnection of devices with different impedances.
[Phono
Connector]
See ::: RCA
[PTFE]
The thermally most stable and chemically most resistant
carbonaceous compound. Electrical properties are very constant
over a wide range of temperatures and frequencies.
[RF
or Radio Frequency]
High frequencies well above the audio band – ranges between
100kHz and more than 1000MHz [1GHz]. RF frequencies can distort
audio signals by interfering with the audio band.
[RCA]
RCA or Phono connector is the type of unbalanced interconnection
most used in the audio world. RCA stand for »Radio Company
of America« . RCA connectors are available as basic connectors
as well as precision versions with very tight production tolerances.
[Reactance]
Reactance is the the non–resistance part of impedance.
It is a combinational effect of capacitance and inductance.
While a pure resistance is stable with frequency, the reactance
varies with frequency.
[Reflection]
See ::: VSWR
[Reflection
Coefficient]
The ratio of the amplitude of the reflected wave to that
of the incident wave.
[Return
Loss]
The difference between the power incident upon a discontinuity
in a transmission system and the power orginating from the
device.
[Screening
Effectiveness]
Ratio of the power fed into a coaxial cable to the power
transmitted by the cable through the outer conductor.
[SPDIF]
Standardised, unsymmetrical digital interface / coaxial
interconnection with 75 Ohm cable impedance.
[SPE]
Polyethylene with homogeneously distributed individual
gas cells included [foam]. Used primarily as a dielectric material
and has an extremely low dielectric constant and power factor.
[Structural
Return Loss, SLR]
The structural return loss is the ratio of incident signal
to the reflected signal in a cable, refered to the measured
cable impedance respective the uniformity of a transmission
line's impedance.
[Symmetrical,
Balanced]
Method of signal transmission with separate ‘go’
and ‘return’ conductors, which are electrically separated
from the shield. – A further advantages of the symmetrical
technology is the fact that no current flows via the earth
[ground] conductor which would otherwise cause a drop in earth
voltage, and as a resultant shift in the important earth reference
potential of amplifiers and others devises. Symmetrical signal
transfer is also a good choice transfering a signal over a
long distance [e.g. active loudspeakers, power amps placed
near to speakers]
[Unsymmetrical,
Unbalanced]
Method of signal transmission where one conductor is used
for shielding as well as signal transmission.
[VSWR]
Abbreviation for Voltage Standing Wave Ratio. The ratio
of the maximum to minimum voltage set up along a transmission
line by reflections.
[XLR]
XLR connection system, also called »Cannon« connection, is a frequently used interconnection systems for
three wire–leads [XLR–3]. XLR3 – connections are widely used
within symmetrical [balanced] analogue as well as digital [AES
/ EBU] interconnections. The XLR connection does not have a
specific RF impedance.
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