Frequently asked questions – Scientific Atlanta 4250HDC User Manual
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Frequently Asked Questions
What is Digital Television?
Digital television (DTV) is a huge leap forward in television technology compared to analog
television that has been widely available since the 1940s. DTV is delivered and displayed using
digital encoding, similar to the way a PC operates. By using digital technology, there is no variation
in picture and sound quality from the origination point until it is displayed on your television. You
always receive a high-quality picture without the wavy lines or static you might sometimes get from
a weak analog signal.
Because DTV receives and displays digital images that contain many times more picture elements
(pixels - the small dots that make up the color image on your screen) than standard analog
television, you can get a sharper on-screen image than with analog. Additionally, DTV supports
CD-quality sound. DTV includes SDTV (Standard DeÞ nition Television), EDTV (Enhanced DeÞ nition
Television), and HDTV (High-DeÞ nition Television). That means that all HDTV is digital, but not all
digital TV is high-deÞ nition. A high-deÞ nition program must originate in HD format and be broadcast
in HD format. Having an HDTV system does not mean that everything you watch will be in high-
deÞ nition. Getting the signal from digital cable also does not mean it is high-deÞ nition.
What is Standard-DeÞ nition Television?
Standard-deÞ nition television (SDTV) is basic digital television programming delivered by cable.
Typically, the SDTV screen is the same, nearly square shape as an analog television screen. Digital
images on an SDTV set are crisp and clear—noticeably better than on a standard analog television
set using an antenna to receive over-the-air signals.
What is High-DeÞ nition Television?
High-deÞ nition television (HDTV) is a completely new way to send and receive television broadcast
signals. HDTV images are made up of pixels that are much smaller and closer together than those
used in standard analog television, and there are millions of them. Thus, HDTV can display Þ ve
to six times the detail of analog television to deliver picture quality that is much more realistic,
dimensional, and precise. SDTV programs can be viewed on an HDTV. Another feature of HDTV
is digital surround sound using Dolby® Digital, which is the same technology used to produce the
sound you hear in movie theaters.
Are Local TV Stations Broadcasting in HDTV?
Many local TV stations are transmitting digital signals. However, transmitting a digital signal does not
mean transmitting an HDTV signal. Some stations are using the new bandwidth to broadcast several
standard-deÞ nition channels. Most stations, once they begin broadcasting in digital, are offering HD
content from their parent network (for example, CBS, ABC, NBC, Fox, WB, UPN, and PBS).
What is an M-Card Module?
An M-Card module is a CableCard that allows the set-top to decrypt subscription digital channels.
The module Þ ts into the Multi-Stream slot on the back of the set-top (see page 4 for the location of
the slot). You can obtain a an M-Card module from your service provider.
Note: Your service provider may provide this when you Þ rst receive the set-top.
Where Are the Connection Diagrams?
The diagrams at the end of this guide show examples of common ways to connect the set-top to
your other electronic devices. However, these diagrams do not show every possible combination
of devices. Refer to the user’s guides that came with your other electronic devices for further
information.
What Cables Do I Need?
Some of the cables and adaptors shown in the diagrams may not be included with the set-top.
Some of the required cables are shown in the connection diagrams and on page 2 of this guide.