Experimental
Television
You can be an image maker too.
INTRODUCTION
Except
for some "old timers", most people believe that television came on the
market in 1947 or thereabouts. Few realize that its development began before the
civil war. The hope then was to transmit photographs over the existing telegraph
wires. Much of the early work was very limited by the hardware. As early as 1907,
a complete electronic television system, similar to the one in use today, was
described by a well-known engineer of the day, but it would be many years before
such a system could be actually built.
By
the middle to late 1920's, engineers like John Logie Baird of Scotland and C.F.
Jenkins of the United States began building mechanical television equipment utilizing
the persistence of vision of the eye. They used scanning disks (or one of its
derivatives) with photo electric cells to construct the images and another disk
revolving in synchronism, to reconstitute the image. Early receivers had a neon
lamp behind the disk to provide the light to form the visible image. Their equipment
could produce recognizable moving images of persons, shapes or forms. In 1928,
Baird successfully transmitted images of London to New York, 34 years before the
Telstar satellite transmitted images of London to New York, across the Atlantic.
In the same year, he also demonstrated for the first time, television pictures
in full color. By 1930, Baird was marketing the "Televisor"; the first
mass-produced television set.
Developments
came rapidly during these years and by 1931-1932, many broadcasting stations were
scheduling regular television programs. By this time, its been said that over
500,000 receivers had been manufactured or were built by home constructors. "Lookers
in" (as Mr. Jenkins liked to call them) were very enthusiastic about their
reception of his signals. Many wrote to the stations describing their scanning
equipment and told how they managed to see a persons lips move or smoke rise from
a cigarette. But mechanical television was not destined to become a commercial
success because the pictures were small and limited to close-ups. Just as experimenters
then became excited by actually seeing pictures on these mechanisms consisting
of motors and spinning disks, today you and I can enjoy the same thrills, seeing
what they saw, with equipment like they used that you can build yourself. If you're
"handy" and have tools, you can build it all. If not, purchase those
parts that you don't feel comfortable in making, but make the rest. It was common
then for experimenters to buy some manufactured components and build only a portion
of their scanning receivers. You can purchase similar materials today that are
the same as those used in my own equipment. These parts are tried, proven and
they will work for you! Those of you that have the skills and tools can and should
should build their own components, using the information available on this site
or in such books as "THE
MECHANICS OF
TELEVISION".
This
book provides information for building various types of cameras and receivers,
which together produce operating systems that really work, with all of the attributes
of early equipment. And with a little extra effort, a cabinet can be built along
the lines of those used with original receivers. Mechanical television is a very
special unique and fascinating hobby. It can and will further the skills of anyone
that participates, young or old. The equipment never fails to attract attention
and capture the interest wherever it's shown.
Many
friends and acquaintances keep telling me, "Peter.... nobody wants to build
anything any more! Look at all the kit manufacturers that have gone out of business.
No doubt a lot radio collectors would like to have working mechanical TV for display,
but no one wants to take the trouble to build one."
I don't accept that.
I
have letters and pictures from many people who have built or are building cameras
and/or receivers based on information available in my book. Judging from the pictures
I've seen, I'd say that many of them are either mechanics, machinists, electricians,
carpenters, technicians or engineers. I happen to know that there are also a couple
of doctors out there working on these things. Construction methods do vary quite
a bit. Some use mostly wood in their assembly and others tend to use more metal
and plastics. It depends on what you can get your hands on and what you are used
to working with. Most builders prefer to buy the electronics rather than build.
But the thread that ties all of these people together is the enthusiasm their
letters exude when describing their projects and the results they have achieved.
Like
most projects, the most difficult thing is getting started... This is especially
true if the project appears to be totally different from the things you've been
doing up to now. But once you get involed, you will learn as you go. Later you
will be doing things that you might not have attempted earlier. The more you become
involved, the better you understand the system and the better you're able to make
the equipment perform. This kind of project is suitable for anyone from age 9
to 90 and if you do get stuck, I or others will help you.
The
Narrow band Television Association (NBTVA)
is dedicated to television experimenters. They offer many parts and supplies at
very low prices. They also send out an interesting quarterly news bulletin to
all paid up members, that gives them first hand information that dovetails with
ongoing NBTV activities. I've been a member a long time , and I strongly suggest
that you join up too. It costs very little and I can't say enough nice things
about this group. Contact them through their web site. Click on the link above.
Peter
F. Yanczer
Note: The photos on this page
is just a small sample of those taken with my own mechanical television equipment,
through the years.