October 1957 Popular Electronics
[Table of Contents]
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
1950s was a time of transition in the television watching business.
Broadcasters were experimenting with pay-TV systems to replace or
supplement over-the-air service. Much as people today think that
everything on the Internet should be free, the same mindset prevailed
then regarding television programming. Early coding and decoding
schemes seem really hokey by today's standards, using computer-type
punch cards. I remember the area around Annapolis, Maryland, where
I grew up, had both over-the-air and cable-based subscription services
in conjunction with the open broadcasts. I spent at least a little
time playing with the horizontal and vertical picture sync settings
on the back of the TV set that, if lucky, would produce a stabilized
picture for at least a little while since at least some of the simpler
"encoding" involved inverting the standard synchronization pulses
in the analog waveform. I have posted at least two other articles
from the era on the same topic: "New
," in a 1953 Radio & Television
," in a 1958 Radio-Electronics
Pay for TV?
By Mike Bienstock
Subscription television - what it is and how it works
What is this thing called pay-TV? More and more it's been in the
news lately, and chances are that very soon the FCC will hand down
a decision on whether to allow a public test or not. So let's examine
it, take it apart and see what makes it tick.
subscription television, to use the technical term) is just what
the name implies - television service for which the viewer pays
rather than the sponsor. Without going into the name-calling aspects
of the controversy, there are powerful elements opposed to the system,
and equally powerful elements in favor of it. Therefore, the FCC
- which has been examining all aspects of the situation for several
years - has a ticklish decision to make.
The system itself
can be used in two ways: broadcast transmission on one or more channels,
with the viewer choosing the program he wants to see and paying
for it; or closed-circuit transmission, paid for on a program basis
or by a monthly flat fee.
Each method has its proponents,
but at the moment the FCC enters the case only in the broadcast
aspect, since it has the power to regulate such transmission. It
is possible that in the future the agency may rule that it has power
over interstate closed-wire television also.
The key to
the broadcast transmission scheme, of course, is a means of preventing
just anybody from receiving the programs. The three major firms
in this field have all turned to coding (scrambling), which presents
Basic operation of broadcast subscription
TV is exactly the same as normal television. The big difference
is the insertion of a scrambler step before transmission and a decoder
at the receiver.
If they scramble the picture and
sound (they believe sound must be coded too, because they've found
that people will just listen to the sound and enjoy it), there must
be some way of unscrambling it. So, naturally, they will provide
their customers with decoders. But there's the rub. Some people,
principally the proponents of closed-circuit transmission, claim
that any coded broadcast could be bootlegged (uncoded by those not
paying for it) with the greatest of ease.
Programming the Zenith decoder.
Decoder used by Zenith has numbers set by knobs, obtained
by punch-out card.
Those sponsoring broadcast transmission deny it. They say that it
would be an extremely difficult process and, in these prosperous
times, wouldn't seem worth the work. Scrambling.
First let's examine scrambling. Generally, three types would be
used, individually or in random order. One is coding by line groups,
in which groups of lines are shifted in relation to each other,
giving a Venetian blind effect whereby each of the "slats" forming
the picture is moved in relation to the next.
is the second type, in which the two fields of the picture are shifted
in relation to each other. The normal field results from the way
the picture is "painted" on the tube. In the 525-line picture, first
alternate lines are transmitted, then the lines in between, but
in such rapid sequence that you "see" both fields. In coding the
fields, the two sequences would be shifted out of relationship,
so you would see a blurred series of images rather than a clear
The third form is essentially the same as the first,
except that instead of coding groups of lines a single line is shifted
out of phase with the next. In addition to this, inversion of polarity
is used just to confuse the picture. Here white would appear to
be black, and black white.
When all three types are used
in random order, with reversal of polarity thrown in for good measure,
the result is quite definitely impossible to make out.
The coded picture, to be viewed, must
be decoded. There are three decoding systems currently taking the
spotlight which are ready for action.
Skiatron uses a decoder
which is keyed by a printed-circuit IBM-type card. The card is inserted
and the viewer presses a button. The circuit is closed and the device
automatically clears up the picture. At the same time, it punches
the card as a record. At the end of a month, the card would be sent
back, the total tallied, and the next month's card sent to the viewer.
Zenith uses a decoder on which five knobs can be turned
to form a series of numbers, A punch-out card provided by the firm
supplies the proper number for the day in question, and would work
only for that decoder. Punched holes form the basis for billing.
A small electronic computer is used to "devise" the numbers for
Paramount's Phonevision, which was originally
conceived as a telephone transmission operation, has since switched
to broadcast, but in this case, rather than numbers and cards, a
coin box is used. When the proper number of coins has been deposited,
the picture will be unscrambled. Closed-Circuit
If the FCC fails to approve tests
of broadcast pay-TV, the industry will be forced to fall back on
closed-circuit transmission. In this case, a huge wiring program
would be entailed. While this might not be too costly for smaller
towns and rural areas, it would involve considerable expense in
metropolitan areas where telephone and utility wires are underground.
On the West Coast, however, some communities - such as the city
of Los Angeles - have most of their utility wires on poles above
ground. This would simplify closed-wire installation to a tremendous
Skiatron has claimed to have developed a new light
line which is inexpensive, yet would be able to carry three signals.
Such a line would cut down costs tremendously. Otherwise, of course,
coaxial cable would be used.
Skiatron's system uses printed-circuit card inserted
Jerrold, a firm which specializes in community antenna systems,
claims that closed systems are the only practicable types for subscription
television, since, the company says, it is simple to devise an unscrambler
which would decode any picture. Jerrold stated before the FCC that
it is prepared to file for a patent on such a device. Also, this
firm points out that there are scores of communities already wired
for master antenna systems, and calls for FCC-sponsored tests in
such an area. It adds that there would be no problem of "bootlegging"
the signal, since service would be supplied by simple switching
as in a telephone office.
Jerrold is in the process of setting
up such a system in Bartlesville, Okla., which will be run by a
theater chain. Three channels will be available, one offering 13
first-run movies, another second-run pictures, and the third background
music, news and time; for this entertainment package, the subscriber
will pay $9.50 a month.
Typical of encoding systems which will
scramble picture and sound is this one used by Zenith. The monitor
in front keeps continuous check on picture "quality." Although this
is a rather elaborate setup, other coding installations are simpler.
A closed-wire system would need no scrambling. since programs would
be routed to customers by means of a switching system similar to
one used for a telephone switchboard.
the Future Holds
Under both types of transmission,
the programs are expected to be first-run movies, Broadway plays
and musicals, sports, opera, symphonies and certain special events,
as well as strictly educational programs.
In some quarters
this is seen as being the ruination of the movie industry, but others
claim that it would be its salvation. Some say that to force the
public to pay for a broadcast would violate the "freedom" of the
air; others point out that the public is actually paying for commercial
television now through buying the products of the firms that pay
for the air time.
One thing is certain. In one way or another,
there will be a form of pay-TV in the not-too-distant future. Whether
you will be willing to pay from 25 cents to a dollar or more for
such entertainment will be up to you to decide. But it will be there
for you to make the choice.
Posted February 10, 2014