SOURCES
Antennas Direct
www.antennasdirect.com
Antenna Web
www.antennaweb.org
DTVAnswers
www.dtvanswers.com
DTV Transition Federal
Communications Commission
www.fcc.gov/dtv
National Telecommunications and
Information Administration
www.ntia.doc.gov
www.dtv2009.gov
TV CHANNEL FREQUENCIES
VHF — Channels 2-13.
Channels 2 to 6 (low band): 54 MHz to
88 MHz. Channels 7 to 13 (high band):
174 MHz to 216 MHz.
UHF — Channels 14-51: 470 to 698 MHz.
Note: Each channel is 6 MHz wide.
analog TV may or may not work for
DTV. For DTV, you just have to
experiment. Once you set up your
converter box, try the antenna you
have been using. Chances are that
this antenna will work for DTV. Try it
out before purchasing a new antenna.
If you have reception problems, a
good next step is a new, improved
indoor antenna. There are dozens to
choose from, ranging in price anywhere
from $30 to $80. Most of these are
amplified antennas giving you the extra
gain sometimes needed to make the
digital signals strong enough. And
don't forget that these indoor antennas
are also directional. You have to rotate
them to get the strongest signal.
There are a few indoor antennas
called smart antennas that have built-in
rotational capability and come with a
remote control that lets you tweak the
direction from the couch. Most are
amplified and automatic. While these
work well, you still have to position
them so they can get maximum signal.
Just play around with placement.
Reception of digital signals is really
different from analog signals. Analog
signals fade and get weaker, and the
picture degrades slowly into a snowy
mess. With digital signals, you either
get the signal or not. In some cases, you
will get the brief pixilation effect then
zap — nothing. It’s either a good picture
or just black. You will need a little more
signal strength with digital than with
analog to get a picture. So, if you are out
in the fringes of the station coverage,
you may need an amplified antenna or
an outdoor antenna. Most rabbit ears
and indoor antennas are good for up to
about 40 miles from the station. Just
remember, these UHF signals hate going
through walls, roofs, and trees. The
higher frequencies are more easily
absorbed by surrounding objects than
VHF signals. Reflections are more common, as well. (There have been actual
cases where a signal directly from the
transmitter was blocked, but a strong
signal was received from a reflection
source like a water tower. Weird but true.)
You can get a good flat panel
outdoor antenna for about $50. It is
unobtrusive in its white plastic case and
is usually amplified. Just point it in the
right direction, mount it, and enjoy (see
Figure 2). The secret to a good outdoor antenna is to get it up as high
as you can. UHF
signals are truly line
of sight (LOS), so
your antenna needs
to "see" the TV
station antenna as
best it can. If your
local stations have different antenna
locations, you may need a rotor to
turn the antenna in the right direction.
In most metro areas, the TV stations
try to co-locate their antennas on one
tower so your antenna orientation
can be fixed. (That is not always the
case, though.) Rotors can be a pain
to set up, but do work well. For
fringe reception beyond 40 miles, a
bigger antenna array is needed.
Figure 3 shows a couple of examples
of high gain antennas. High gain
implies high directionality so you will
most likely need to pay closer attention to the orientation than you did
before. Or, you will need the rotor.
One final thing about outdoor
antennas. Many communities frown on
outdoor antennas. Most home owner
associations have covenants forbidding
them. A few allow satellite TV dishes as
they are small but a big TV antenna may
be a real no-no. So check this out to see
what is possible before you buy anything.
You could put the antenna in an
attic, if you have one. Putting the
antenna inside always attenuates the
signal so get a high gain antenna
with amplification to offset this.
One other thing is that at UHF
frequencies, coax cable attenuation
is far greater that the attenuation at
VHF. What that means is you will
lose more signal in the cable than
you did before. So, keep it as short
as possible, and use higher quality
cable. For example, RG-6/U coax is
75 ohm cable like the more common
RG-59/U but has far less attenuation.
(That’s why the cable TV companies
use it exclusively.) Replace your old
coax if it is more than a few years old.
FINAL THOUGHTS
26
■ FIGURE 3. Two popular types of outdoor antennas
that work with DTV. The first is a typical flat panel
antenna. You can hardly tell it is an antenna at all.
It does need to be positioned high and oriented for
best reception. (Photo courtesy of Lacrosse and
Antenna Web.) The second is the familiar Yagi
configuration. The smaller elements are for the
UHF channels. You will probably need a rotor if you
watch more than one station and the stations are in
different locations. (Photo courtesy of Antenna Web.)
February 2009
You will probably have to experiment with the antenna situation to get
a satisfactory picture. It is a whole new
ball game with digital UHF signals, but
there is a solution out there for you.
Check out the options at your local
electronics store. And remember, there is
tons of great information on the Internet.
Check out the list included here which
gives you the best sources of additional
information. And if all else fails, just
sign up for cable or satellite TV.
NV
