textfiles/hamradio/sca.txt

SCA: FM Radio's Alter-Ego - The Radio The FCC Doesn't Want You To Own
From March, 1989 Monitoring Times. By Bruce F. Elving, Ph.D

   It has been ignored by the consumer press. The high fidelity and stereo
industry doesn't talk about it. Certainly, few FM listeners are aware of it.
"It" is a medium of communication available free for the taking in almost all
parts of North America -- namely, FM subcarrier broadcasting.
   First demostrated in 1953 by FM's inventer, the late Edwin H. Armstrong,
multiplexing of more than one program on a single station's carrier was
authorized to begin in the United States by the Federal Communications
Commission in 1955. Long since eclipsed in the public eye by another
multiplexing development, FM stereo, subcarrier FM has been largely the
province of special interest groups, instead of the public.
   FM-SCA listening has enjoyed a steady growth in the last 30 years, thanks
largely to magazine articles showing how to assemble FM subcarrier contruction
kits and to companies supplying the components and radios to make such
listening possible.
   Indeed, the distinction between FM-SCA and FM stereo, both of which can take
place on the same FM station, is blurring. Both are "multiplexed" transmissions
and both can be enjoyed by the public in large numbers, the difference being
that stereo FM is identical to the regular FM program, while SCA FM is [almost
always] different from the regular FM station's programming.
   Not all FM stations make use of an SCA, but I am sure more would, if the
owners had personal access to SCA radios in order to explore the fascinating
and often money-making things that can be done with this wonderful medium. SCA
can be received as clearly and reliably in the local service area as the
regular FM station.
   My FM ATLAS AND STATION DIRECTORY has publicized the existence and nature of
SCA programming, and this led to curiousity as to how SCA-FM can be received.
This caused us in 1977 to explore the business, legal and technical aspects of
SCA tuning-in. In the years since, we've offered SCAdapter devices to the
public, as well as conversions of radios to pick up SCA transmissions.
   In our early days we fought off several threats of lawsuits from entrenched
SCA interests who would like to keep SCA private and out of the public's
radios. More recently, the FCC deregulated SCA, allowing more uses of the SCA
signal, including data services and freeing stations from having to get
specific advance approval before embracing an SCA ["Subsidiary Communications
Service"]
   That term was changed to SCS ["Subcarrier Communications Service"], with
this article using the letters SCS or SCA interchangeably. Canada has a similar
service called SCMO.

   In deregulating the medium, the FCC utilized our data showing the degree of
SCA utilization nationally by broadcasters. In so doing, the FCC announced its
intent to encourage broadcasters to make greater use of SCA, and it created a
new SCS channel, 92 kHz, which enabled broadcasters to make greater use of
their station bandwidth.
   The two common subcarrier frequencies are thus 67 kHz (the granddaddy of
them all), and 92 kHz. One FM station can send out all three programs
simultaneously -- a stereo program to its regular audience and two separate
programs on SCA, such as a radio reading service to the blind at 67 kHz and
foreground music on 92 kHz.
   Another channel -- 57 kHz -- is in use exclusively for data. Data includes
highway condition alertings in many metro areas and digital paging. It is a
channel not favored by at-home listeners, because it is devoid of talk or music
programming.

LEGALITIES
   Because FM-SCA is a technology which is multiplexed and "readily available"
to large numbers of the public, tuning in its transmission is no more sinister
than owning and using a police radio, public service band scanner, radar
detector, listening to FM stereo, or watching color television. Virtually all
laws prohibiting the use of such devices have been struck down by the courts as
being in violation of the First Amendment to the Constitution.
   Apparently, however, government can control where you can use these devices;
such as forbidding the use of scanners in private automobiles. Similarly, you
should be able to listen to background music on SCA in the privacy of your
home, but not in a business that you own if it might deprive the music company
of rental income for equipment to play the music in the store.
   You enjoy further legal protection if the radio, even though modified with
an SCA circuit, is a radio designed primarily to tune in other transmissions
(like regular FM and AM), rather than its being designed solely for subcarrier
reception.
   Anybody questioning the legality of tuning in SCA should contact local
broadcasters for a letter of permission authorizing tuning in their subcarriers
for noncommercial, hobby purposes. Please send us any such letters you receive
from broadcasters.
   All FM stations known to have an SCA are listed in the latest edition of the
FM ATLAS; write the author for price and ordering information. The very
distinction between who is an "authorized user" and who is a "pirate" is a fine
one, and one that even the courts would probably shy away from.
   Although at this writing the FCC is unwilling to encourage the use of
tunable SCA radios, the FCC noted that the frequencies received by many
electronics devices, including scanners, can be used for unprotected
communications as well. "Thus, the suggestion that the Commission require that
reception of certain frequencies be blocked or filtered is not a practical
one."
   The FCC pointed out that it is not a guarantor of any electronics privacy
protections. It is even legal to eavesdrop on cellular telephones, using
commonly-available UHF TV sets in the channels 79-83 range.
   SCA or SCS is a valuable and relatively unexploited resource available to
the public and to the FM broadcaster alike. Despite the use of better
transmitting equipment, some broadcasters still entertain prejudice against
SCA, thinking that subcarrier use will somehow compromise the quality of their
main channel signal. The FCC has helped by allowing stations to increase their
overall modulation to compensate for having an SCA, and there is no evidence
that having an SCS will decrease a station's ratings.
   The needs of a growing population to be better informed about specialized
matters will dictate more uses of SCA, rebounding to the benefit of FM stations
and the public alike. By taking SCA "out of the closet," our efforts could
result in SCA's being included in every FM radio sold in the United States in
the future.

PROGRAMMING
   SCA's programming has considerably broadened since 1977, when most of the
use of the medium was background music to stores. Radio reading services to the
blind were just getting underway; they are now found in most metropolitan
areas, or across entire states, usually on the subcarriers of public stations.
Overlapping reading services can be tuned in in such areas as Wichita, Kansas
and along the Minnesota-Wisconsin borders.
   It is a pity that most SCA radios are fixed tuned, getting only one station,
and not allowing blind citizens who travel or who live in areas having
overlapping signals to tune in all that they could. There is ethnic programming
in many major markets, at either 67 or 92 kHz. Foreground or light rock music
predominate on 92 kHz. Many stations have an easy-listening SCA at 67 kHz. With
the demise of easy-listening from many commercial FM stations, SCA remains the
only way for millions of people to hear that format on radio.
   In certain areas of the country you can tune in religion, medical news,
relaying of sports and special events, or even AM stations on SCS. With many AM
stations having financial troubles, it might make sense for them to direct
their efforts to being on the SCA of a nearby FM station than face the prospect
of ultimately closing down.
   Listeners with radios so equipped could hear the regular FM program, and
then flipping a switch, hear an SCA containing their favorite AM station. SCA
has a monaural signal with a bandwidth up to 7,000 Hz, or about as good as the
best AM stations send out. Its benefits include coverage range similar to the
main station stereo signal, and the ability to broadcast a whole new program
without having to create new transmitters, build new towers, or pay the power
bills necessary for running a complete radio station. SCS is truly a piggyback
service.
   With the FCC concerned about "deregulation," and removing artificial
restrictions in broadcasting, the time is ripe for broadcasters and the public
alike to turn to FM-SCA. Let its crystal-clear signal peal out with music and
information in clear voice -- content that can inform, uplift, extoll, or even
upbraid.
   To computer activists, SCA offers a world of data, whose unencryption can
challenge the most technically adept. Broadcasters, however, know the world of
sound, and it is talk and music services which they should consider when
addressing SCA opportunities. By offering alternative programming, whether for
profit or not, they can complement what they are doing with their main
channels.
   A public station could provide music on its SCA while carrying news-magazine
programs on the main channel. A commercial station could offer its regular
music format while broadcasting sports on SCA, or vice versa. A rock station
could offer its easy-listening or talk formatted AM signal via SCA, especially
if the AM has coverage problems, or if located in areas having high
concentrations of high-rise buildings with steel construction, making for poor
AM reception (but unimpaired FM-SCA reception).
   The fact that hundreds of thousands of folks are out there with tunable SCA
radios, as is the case in the New York city area alone, should be of little
concern to the stations or the SCServices. The public at large may have some
curiousity about hearing the reading service station, ethnic programming,
medical news, or background music, but this is a transitory interest, far
eclipsed by the tunings-in of those to whom such broadcasts are intended.
Indeed, this large audience is something that could be programmed to and
nurtured.
   Third parties can get into the SCAct by approaching the manager of a local
FM station with ideas as to how its SCS could be providing a profitable or
meritorious service in exchange for a nominal monthly rental to the station.
SCStations are free of such FCC restrictions as the equal time requirement in
political broadcasting, although ultimately the FM station licensee is
responsible to the FCC for the contracts it has with the people to whom it
leases an SCA, and for having a general knowledge of the nature of the SCA
eminations, including foreign language or what type of data is being sent out
to computers, pagers, and similar instruments.
   Reading services on SCA get away with audio pornography that would not be
tolerated by most stations if it were on a main carrier, and you can pick up
private point-to-point messages on SCStations having tone-and-voice paging
services.
   To the casual listener or would-be SCA broadcaster, the opportunity is there
for a new form of electromagnetic discovery. Not only are the programs
different, but the reception characteristics differ. Some stations run their
SCA only part of the time. Others run different services on the same channel at
different times, while still others experiment with it, sometimes turning the
signal on seemingly only for the engineer's amusement.
   Even trying to find out information from some SCA stations can be far from
routine. Not everybody employed at the station knows that an SCA exists or what
it is used for -- and if they know, they may be paranoid about it and not tell
you. Yet, it behooves those employed at an FM station to find out about its
subcarriers. The SCA may be helping to make the station more profitable, and
make possible the paying of your salary.
   Listeners should be aware, too, that many a public or religious FM station
that may be begging you for funds could be raking in the dollars by offering
for-profit data, music, paging or other services -- something they're not very
likely to mention, but nevertheless a significant source of income or potential
income.
   Being able to tune in SCA at home, ona portable, or on a car radio is the
absolute elitism in radio listening. You are in a class unlike 99 percent of
your neighbors. Considering that SCS is sent out with only 10 percent of the
energy that the main FM station uses, reception of SCS under most conditions is
surprisingly good and uncritical when the receiving equipment is properly
installed and used, although it does suffer from multipath distortion and
crosstalk problems.
   To get good reception, place your radio in a spot getting a clear signal
from the FM station with no multipath interference.
   Until the day comes that you can visit your favorite store and buy an FM-SCA
radio, you may have to use some ingenuity in tuning in SCA. It should be well
worth the effort to familiarize yourself with this medium -- and the best way
to do so is with your own FM-SCS radio or adapter unit.
   Dr. Bruce F. Elving is editor of the FM ATLAS AND STATION DIRECTORY and
FMedia! Readers may contact the author at Adolph, Minnesota  55701.

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   Most music is entertainment and is meant to capture and hold your attention.
Yet, research has proven that when properly arranged and recorded, music can be
used to do just the opposite. It can help people concentrate better on whatever
they are doing and reduce the distraction of noise at the same time.
   Why should background music be used instead of playing other sources, such
as AM-FM radio? Playing radio's commercials in the workplace does not make good
business sense, especially when it's playing competitor's commercials, and
could require the nuisance of registration and payment of music license fees.
If a tape player is used, it would need time-consuming care in maintenance and
cleaning. Tapes must be changed. Music quickly becomes repetitive.
   Background music can keep shoppers in a store longer, while "foreground
music" is designed to meet the need of businesses wanting a more contemporary
sound. Foreground music is usually played at a louder volume and is meant to be
consciously listened to.
   Inspirational Audio Music by Roy Swafford is a music format designed to
create a Christian atmosphere in a business. Most background music services
utilize satellites to send the programming to the individual stations, which
send them out in turn by FM-SCA or SCS.
   An engineer at KHOZ-FM 102.9 Harrison, Arizona is quoted: "Most satellite
receivers can receive audio subcarriers like Muzak and it is not illegal to
listen to them. It is also legal to purchase an SCA receiver. Yes, you are
eliminating the background music companies who charge a fee, but that's only in
terms of businesses, not for the private individuals. There is no such law that
says, 'all must pay a fee who listen to SCA'."

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