December 1958 Popular Electronics
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Popular
Electronics was published from October 1954 through April 1985. All copyrights are hereby acknowledged. See all articles from
cares about television antennas these days, you're probably
asking? Many people might care soon. The December 2012 edition
of the IEEE's Spectrum
magazine had an article titled,
Future: The Broadcast Empire Strikes Back
." According to
author Lynn Claudy, the Advanced Television Systems Committee
working on a standard called
(MDTV) in the United States. MDVT enables broadcast
stations to deliver programming to some cellphones, laptops,
tablets and to moving television screens in cars, trains, and
buses. Furthermore, a scheme to enable on-demand programming,
user feedback (voting, polls, quizzes, games), and other advanced
features is under investigation in research labs and field trials.
Local businesses welcome a rebirth of regional over-the-air-broadcasts
(OTA) to provide pricing competition with dominant cable TV.
So, although this article was originally written in 1958 when
only OTA broadcasts existed, it may soon be a valuable resource
for you and your neighbors when deciding on which antenna to
put up on the roof. Antenna rotator article are forthcoming.
Choosing Your TV Antenna
By Rudolf F. Graf
The best TV antenna made isn't good enough for your set unless
it's matched to the needs of your location. Distance from the
transmitter is the biggest factor affecting TV reception, but
local terrain, adjacent buildings, or mountains can cause the
signal to come in strong or fade out altogether regardless of
distance. The only way to insure a good signal is to choose
the right antenna for your location and for the channels used
Television reception areas are broadly classified by their
distance from the station:
• Primary or local area (up to
• Semi-fringe area (up to 50 miles)
area (up to 75 miles)
• Deep fringe area (up to 200 miles)
By the time the signal reaches the receiver location, it
may be quite weak. Therefore it's important to have the best
possible antenna installation. Height, type and direction are
all important factors.
Adjacent-channel interference, which is a frequent troublemaker,
seen as weaving diagonal lines, is caused by a signal from the
next higher or next lower station. If you are tuned to Channel
11, for example, a strong station on Channel 10 or 12 may cause
On the other hand, co-channel interference (vertical "windshield
wiper" or horizontal "Venetian blind" black bars) is caused
by a station operating on the same channel as the one we are
trying to receive. This trouble usually crops up if the TV set
is about half way between two stations on the same channel.
Both of these types of interference can be eliminated with
sharply directional antennas. In the case of adjacent-channel
interference, a single-channel Yagi with a filter at the receiver
may work wonders.
No amount of receiver adjustment will banish a ghost caused
by reflections from buildings, mountains or other objects. Antenna
re-orientation or replacement are the only certain cures.
The roof or outdoor antenna is easily the best and most efficient
type. It is desirable in primary areas and absolutely essential
in fringe areas. It may be a single-channel, selective-channel
or all-channel job. About 50 different designs are available
today but selection of any particular one depends greatly on
Folded dipole with reflector. One antenna
for channels 2 to 6, another for channels 7 to 13; each necessary
if both high and low channels are to be received.
Conical antenna with conical reflectors.
Similar to previously mentioned conical antenna but slightly
Conical or fan-type antenna. Model shown
has high-channel stubs. A very popular antenna, with moderate
gain and directivity.
Stacked conical with straight reflectors.
A moderate-gain broadband antenna for use in semi-fringe areas.
Vee-beam antenna. Low gain on Channels 2
to 6, fair on 7 to 13. Each of four elements should be at least
45" long; if not, reception on low channels will suffer, and
an antenna should be used on high channels only.
Stacked in-line antenna. Effective moderate
gain assembly with good response over all of the various channels.
High-low antenna. Individually adjustable
dipoles with reflectors. Good all-around antenna for primary
Five-element Yagi. High-gain directional
single-channel antenna. Separate antenna required for each channel.
In-line antenna. Fairly directional all-around
antenna with good gain.
Helical Yagi. All-channel antenna with moderate.
Performance better on higher channels than on low.
Boom (Crossarm) - The horizontal bar or tube which serves
as mechanical support for all the antenna elements.
Dipole - The simplest of all TV antennas, consisting of two
electrically unconnected rods or tubes arranged end to end.
Transmission line is connected in center.
Directivity - Ability of an antenna to select signals from
one or several desired directions. Antennas may be "unidirectional"
- receive signals from one direction only, or "bidirectional"
- receive signals from opposite directions but not from the
sides, or "omnidirectional" - receive signals from any direction.
Director - A parasitic element placed in front of the driven
element for increased gain and directivity.
Driven Element - That element (or elements) which "collects"
the TV signal. It is connected to the TV lead-in.
Element - Everyone of the working parts of an antenna is
called an element. It may be either driven or parasitic.
Front-to-Back Ratio - A numerical ratio showing how much
more signal is received from the front of the antenna than from
Gain - A figure expressed in decibels (db) which indicates
the signal gain of a particular antenna type over that of a
Mast - The heavy vertical tubing which supports the antenna.
The crossarm is usually bolted to the mast.
Parasitic Element - An element or elements not directly connected
to the driven element. Parasitic elements act as directors and
reflectors for increased signal strength and directivity.
Reflector - A parasitic element or elements placed behind
the driven element for increased gain and directivity.
Stacking - Two or more antennas joined together electrically
with stacking bars or a stacking harness.
Twin Lead - The transmission line which carries the signal
captured by the TV antenna to the TV receiver.
Posted March 21, 2013