Functional Block Diagram - Blonder Tongue Laboratories Inc.

Broadband Specification Guide
CATV Terms & Definitions
Digital Data
Any data which is expressed in digits. Usually implies the use of binary digits.
Digital Signal
A signal which is expressed by discrete states. For example, the absence
or presence of a voltage, the level of amplitude of a voltage, the duration
of the presence of a voltage, etc. Information or intelligence to be
transported may be assigned value or meaning by combinations of the
discrete states of the signal using a code of pulses or digits.
Diplexer
A device used to combine or separate two signals. A U/V band separator
is one example of a diplexer.
Direct Pickup Interference (DPI)
Interference displayed as a leading ghost (left of the main image) on a
TV. This occurs in “on-channel” installations in close proximity to the TV
transmitters (generally within 10 miles).
Directional Coupler
Type of tap that has a designated input and output port besides the tap
port(s). These devices exhibit high isolation between output and tap
ports. Unlike resistive MATV (non-directional) tapoffs, care must be taken
during installation for correct in/out connections.
Dish
A parabolic antenna used for satellite reception.
Dispersion
A term used to describe the chromatic or wavelength dependence
of a parameter as opposed to the temporal dependence, which is
referred to as distortion. The term is used, for example, to describe the
process by which an electromagnetic signal is distorted because the
various wavelength components of that signal have different propagation
characteristics.
Domsat
Domestic Satellite System.
Downlink
Transmission from a satellite earthward. Can also refer to a TVRO
receive station.
Double Window
An optical fiber having desirable transmittance characteristics in both the
first and second window regions.
Dynamic Range
In a transmission system, the difference in decibels between the noise
level of the system and its overload level.
Echo
Reflected energy confined to only a portion of the spectrum which is
occupied by the originating signal.
Educational Broadband Service (EBS)
(Formerly known as ITFS) Microwave Transmission in the frequency
range of 2500 MHz to 2686 MHz.
Electronic
Describing devices, which depend upon the flow of electrons in vacuum
or in semiconductors, such as electron tubes, transistors, etc.
Electron Volt
The amount of energy gained by one electron in passing from a point to
another point which is one volt higher in potential.
Electromagnetic Wave
A wave capable of propagating energy through space at the speed of
light, consisting of electric and magnetic fields at right angles to each
other and to the direction of propagation. Depending upon its frequency
it may be known as a radio wave, a light wave, or a x-ray, etc.
ETV
Educational Television.
Equalize
To apply to a transmission facility a network, whose characteristics are
complementary, such that the loss or delay in the facility and in the
equalizing network combined, make the overall loss or delay almost the
same for all frequencies passed through the facility or network.
Equalizer
A network designed to compensate for an undesired frequency or delay
characteristic of a system or a device.
Equalizer, Cable
A network designed to compensate for the frequency/loss characteristics
of a cable, so as to permit the system to pass all frequencies in a
uniform manner.
FCC
Federal Communications Commission. Regulatory agency that sets
communication standards in the US.
FCC Docket 21006
An FCC ruling which set forth frequency off-sets on certain CATV channels
to minimize potential interference to aeronautical communications.
Feeder
A sub-system within a trunk plus feeder designed CATV system, which
provides complete distribution of signals to subscribers within a limited
section of the CATV service area.
FET Photodetector
A photodetector employing photo-generation of carriers in the channel
region of a Field Effect Transistor structure to provide photo-detection
with current gain.
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