TV
ANTENNAS
If
a TV
antenna
is
mounted high enough
and
connected with
a
properly
installed feedline,
it
should result
in
more available signal
than
the
antennas we've talked about
so
far. Perhaps
not as
much
signal
as a
directional
FM
antenna because
TV
antennas
are
broadband
(54 MHz to
216
MHz for a
VHP
model). However, some
TV
antennas have
special
provisions
for
receiving
FM
signals,
while
the
rest
of the
antenna
is
used
for
VHP
TV
reception. That could
be
more
money than you'd want
to
spend, unless you're using
the
antenna
for
both
TV and FM
reception.
If
you
already possess
a TV
antenna,
or are
planning
to
hook
up to a
master
antenna system
in an
apartment building
or
condo,
it
might
not
work. Some
TV
antennas have
an FM
filter
built-in
to
reject exactly
the
same signals
you
want
to
hear.
If you
fall into
the
group
of
people
who
already have
TV
antennas installed
in
their homes, there
are
still
some
things
you may
want
to do
before
adding
a
splitter
to
supply
signals
for the
TX-11
b.
You've overcome
one of the
costs
in an
antenna system
by
having
the
antenna,
but
possible reinstallation
and new
feedline
may be
desirable, even necessary,
for
proper
performance.
It
will probably also require reaiming
the
antenna. That
could create some problems which could degrade
the TV
reception.
This means you'd have
to
install
an
antenna rotator.
A
rotator
allows
almost
infinite
realignment
of the
antenna
to
produce
the
best
signal
possible
for
stations
you
want
to
hear (and see)
on a
station-to-station
basis.
OUTDOOR
FM
ANTENNAS
When
mounted
and
connected properly,
a
directional outdoor
FM
antenna
can
provide
the
best signal
of
all, with
the
lowest interference
and
noise factor.
The
greatest disadvantage
to
this system
is the
cost
of
the
antenna,
mounting
hardware,
and a
rotator.
The
rotator
is an
absolute necessity
if you
want
to
point these highly directional
antennas
in
more than
one
direction. Most
FM
antennas
of
this type
tend
to be
even more directional than
a lot of VHF TV
antennas, with
or
without special provision
for FM
reception.
In any
outdoor
installation,
the
cost
of a
ground rod, feedline,
and
insulators must
also
be
figured into
the
total price
of the
antenna set-up.
The
combined
totals
can
quickly
add up.
Other than directional
FM
antennas, there
are
outdoor dipole
antennas
that
can
provide
many
of the
same
benefits,
at a
somewhat
lower
cost. You're already familiar with
the
half-wave dipole which
can
also
be
called single dipole antennas.
The
dipole that came with
the
TX-11
b is
meant
to be
used indoors,
and has
just that
one
upper
arm,
or
element.
The
virst variation
on
this
dipole
is an
antenna that
is
really
two
single dipoles
set at
right angles.
It
works
the
same
way
as
the
single
dipole
but
instead
of
picking
up the
majority
of
signals
in
two
directions,
the
dual
dipole
will
pick
up
signals
in a
modified omni-
directional pattern.
Another
outdoor
variation
is the
S-curve
omni-directional
antenna.
For
all
intents
and
purposes,
the
S-curve antenna
is
just
a
single
dipole bent into
a
"S"
shape.
The
change
in the
shape
of the
antenna
makes
its
pick-up pattern
a
little more omni-directional than
the
reference
dipole.
Other
than
the
changes
in
pick-up
patterns,
both
these modified dipoles
offer
more gain than
the
reference
dipole.
On
top of
that, these antennas
may be
installed high enough
to
reduce
the
possibility
of
local interference,
and
some
multipath
interference
problems.
When
totalling
up
costs
for
hardware, these
two
outdoor dipoles
eliminate
the
need
of a
rotator,
but
will
still
require
the
proper
mounting
hardware
and
feedlines.
You
must weigh
and
compare
the
costs
and
benefits
of
directional
vs.
omni-directional antenna systems installed
outdoors
on the
results.
It
could
be the
omni-directionals
will give
superior coverage
and
signal quality
in
your area, making
a
directional
antenna unnecessary.
On the
other hand,
the
directional
FM
antenna
may
be the
only route
to go
because
of
severe localized noise
and
multipath interference problems.
The
point
is
that actual antenna
selection, over
and
above
the
fact
some antennas
are
"better" than
others, must
be
made
on an
area-by-area basis. Terrain, transmitter
locations,
and
your
relation
to
them
will
be the
deciding
factors when
figuring
out
which system will receive
the
signals
the
best.
Installation
Choices
INDOOR INSTALLATION
For
obvious reasons, indoor installations
are the
easiest
to do. It
doesn't
involve much
to
stick
the
dipole that came with
the
TX-11
b
on
a
wall.
But
remember some
of the
drawbacks
to
indoor
antennas:
1)
height,
and 2)
possible problems with interference from cars
on
the
street
and
small electrics
in the
kitchen. Plus, antenna height
is
essential
to
good signal strength
and
signal-to-noise ratio.
An
indoor antenna
can
work
just fine
if
you're
in a
taller
building
with
good
"line-of-sight"
to the
area's
FM
transmitting towers,
or
other
places
where
you get
clean
signals
from your favorite
stations.
If
you've been listening
to FM on
another receiver
in
your home,
you
might
get a
very rough idea
how
many stations could
be
available.
However,
your
TX-11
b is a
tuner with impeccable performance,
capable
of
making stations that were totally obnoxious
due to
noise
and
distortion, sound great! This alone will allow
you to
experience
all the
pleasure
of FM
stereo listening, with
a
less-than-ultimate
antenna.
If you
can't
get a
truly listenable signal from
a
dipole
or
other
type
of
indoor antenna, there
are
other options.
OUTDOOR INSTALLATIONS
Properly
done, outdoor installations
can
offer
vastly
improved signal
quality
over
indoor antennas.
But
there
is the
cost,
and the
actual
effort
of
putting
it all up.
Another, perhaps most important consideration,
is
SAFETY. Safety
is
very important
in
planning,
setting-up,
and
using
your
antenna system. With that
in
mind:
•
Don't
run the
risk
of
having
a
bolt
of
lightning
—
natural
or man
made
—join
you, your
tuner,
and
your stereo system
in the
living
room:
A)
Keep
the
antenna, mast, boom,
guy
wires, feedline, whatever
away
from
all
power lines. That includes
the
lines from
the
power pole
to the
house. DON'T EVEN THINK ABOUT PUTTING
IT UP
WHERE
r
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