| What is Needed to get HDTV Antennas
Antennas are required to receive DTV and HDTV signals from
satellite and over-the-air (OTA) sources.
The
choice of an antenna for OTA reception is complex, as the signal level varies considerably
with distance from the transmitter, channel, terrain and location. At the same time, the
interference from other stations on the same or adjacent channels varies widely. While
over-the-air DTV transmission is far more rugged that analogue NTSC transmission, when it
fails, it fails completely and no reception is possible, unlike analogue transmission
which simply becomes noisy and distorted.
The OTA reception must be chosen to pick up the desired signal(s) with a good margin to
ensure reliable reception under all conditions. In general the following guidelines will
provide good reception in most situations.
(a) Close to the transmitter, up to 15 km.
An indoor antenna will suffice, as long as the signal is not blocked by large surrounding
buildings or terrain. Suitable antennas are available at CE suppliers. A typical indoor
antenna is illustrated.
Typical Indoor Antenna
(b) In the suburban area, 10 to 30 kms f.
From the transmitter, . aA small outdoor antenna will give adequate reception. If the
cable from the antenna is over 30 ft in length, the antenna booster amplifier will improve
reception, particularly on high UHF channels. Such antennas are available from CE
suppliers and a typical unit is illustrated.
Typical Amplified Indoor/Outdoor Antenna
(c) In rural areas, 25 – 70 kms
.distant forom the transmitter, a multi-element outdoor antenna equipped with an antenna
amplifier can provide good reception in many cases, where the signal is not blocked by
terrain (hills, etc.) Suitable antennas are manufactured by Wade, Winegard (illustrated PR-7015), Channel
Master, Antennacraft and others.
Winegard PR-7015 Outdoor Antenna
Some testing and expert assistance may be needed to select,
install and align an appropriate antenna in areas distanced from the transmission site to
ensure that it can deliver reliable HDTV reception..
Some satellite antennas now include an optional over-the-air antenna in the package.
|
