Narrow-band Television
The ICH (Chapter 3) provides a pretty good introduction
to the subject of NBTV and links to web sites where you can follow current developments.
Initially my plans for this page are to cover hardware and software support issues for the
NBTV RomScanner and perhaps track some of my own projects as I get back up to speed after
the effort of getting the book finished up. Later, if there is interest, I will expand the
coverage with new projects, news, and new links.
Why Bother with NBTV?
If you have come this far, you probably have already answered the question to your own satisfaction, but a few points are worth noting. First, NBTV is the ultimate electronic nostalgia trip. We have gotten very casual in the presence of electronic marvels, but NBTV can take you back to the start of it all, when the most fundamental aspects of television were still in the making! The entire "era" lasted little more than a dozen years, but it was a period of intense experimentation and innovation and, when it was over, television in its entirely modern form had come into being. Whether your interests are restoration, recreation, or just curiosity, there is plenty to keep you busy. Most of the pioneers of modern NBTV have been at it longer than the mechanical television era itself!
NBTV has endless potential for building, tinkering, and experimentation! Building and experimenting with electronics has gone out of style, even among Radio Amateurs, but it's alive and well in NBTV. While challenging, the projects are all within the grasp of any diligent experimenter. It is also worth noting that, with today's parts and circuits, success is much easier to come by than would have been the case in the late 20s or early 30s. The additional attraction of the mechanical tinkering inherent in many projects make the whole thing that much more attractive to many experimenters. Those needing instant gratification need not apply!
Finally, there is the potential to actually use NBTV to communicate,
whether via the old technology or the latest computer image compression algorithms. The
only thing more satisfying than watching an NBTV image on the bench is to actually send
that image through space, be it a hundred feet or a hundred miles!
NBTV INFORMATION
Narrow Band Television Association
The NBTVA website in the UK has been growing steadily and has lots of interesting material:
If you are going to experiment with NBTV display systems, the CDs from the NBTVA are an absolute requireement for standardized images. Here are three images from disk #2 as displayed using the Virtual Televisor system. Disk #3 is particularly interesting as it features interviews with members demonstrating their equipment. Each disk typically contains a complete set of images in the club's 32-line format, as well as a duplicate set in the Baird 30-line format. Image data are on the left audio channel while the accompanying sound can be heard on the right channel. Today is is easy to be dismissive about the first decade of television, yet we need to make judgements not from today, but in the context of a brand-new technology. Watching the full-motion NBTV video and listening to the sound, it is easy to see why the proponents of mechanical television felt that it had real educational and entertainment potential, despite the obvious limitations.
The NBTVA is the world center for NBTV activity and experimentation, so bookmark the site and visit it regularly! No matter where you are located, you might wish to consider joining the NBTVA, which will also give you their excellent journal and access to the Members Store for well-priced project materials. Joining has been made considerably easier by the fact that club dues, which previously had to be paid directly in Sterling, can now be paid via PayPal.
This very valuable resource can be reached via the link above or through the Forum link on the NBTV Association website. As in most such fora, you can read the material anonomously, but you will have to join the forum to post or otherwise participate.
Peter Yanczer's Mechanical TV Site
Peter Yanczer's has maintained a website for many years that got innumerable people started with respect to mechanical television. Although he has now arrived at the point where he feels he needs to close the site, Steve McVoy's Early Television Foundation is now hosting many of Peter's old pages.
Steve McVoy's site has fascinating material on both mechanical and early CRT TV systems, much of which you can see at the ETF Museum in Hilliard, Ohio.
Jame T. Hawes Mechanical Television Archive
Lots of interesting information, including design tools that can help you work up some of the basic modules needed for a mechanical televisor.
Gary has some superb Windows freeware that will let you display NBTV with no interface hardware other than your standard soundcard as well as software to produce NBTV video from standard video in the AVI format.
NBTV PROJECTS!
The only NBTV construction project to appear in the
first edition of the Image Communications Handbook was the ROMScanner
picture generator. However, I continue to be working, at a highly variable pace, on
several other projects, most devoted to image display. As time goes by, these will be
listed below with links to more complete pages for each project. Keep in mind that many of
these will start as "works in progress", so don't rush ahead to duplicate the
project until all the results are in - unless of course you like to experiment!
ROMScanner EPROM Image Generator
No matter what your interests in terms of NBTV image
display, you will need a source of stable images, either to align or to demonstrate your
televisor. The ROMScanner fills the bill rather nicely.
Aurora Multi-Standards Converter
If you want a very flexible source
of TV images in a wide range of formats, here is a commercial scan/standards converter
that will do the job!
Virtual Televisor Computer Image Display
Most approaches to NBTV image display result in rather
small pictures that are far from optimum for comfortable individual or group viewing. Here
is a project, based on a parallel port interface to a PC, that eliminates that limitation.
Now that the Virtual Televisor computer
display is up and running, I intend to explore at least two approaches to mechanical image
display - a classic Nipkow disc televisor and a mirror screw system. I don't intend to
break any new ground in circuit design and will be using Peter Smith's video and motor
drive circuits. However, I will be putting all of these on a single compact PC board to
make it easier to build the televisors. While I am not yet ready to proceed at full-speed,
it is never too early to satrt gathering critical parts such as scanning discs, motors,
etc.
32-Line Nipkow Disc Design Program
This program will not plot your disc for you, but will generate all the values you need to do the job. You can start with a disc of a set diameter or you can specifiy the height of the image. The program lets you work in either inches or millimeters.
Ralph E. Taggart (gyrobee@aol.com)