TELETEXT RECEPTION
As suggested in Chapter 2 there are several ‘free’ TV lines in the field blanking interval of the broadcast vision signal. For many years these have been used to carry VITS (Vertical Interval Test Signals) in the form of pulse-and-bar and chroma signals: they are used for engineering tests on transmission lines and r.f. links. Other TV lines are used to convey data in the form of alphanumeric characters and graphics in coded form. A suitably equipped receiver can display pages of text and graphics, either alone or superimposed on the broadcast picture. Regularly updated magazine items such as news, travel information and share prices are transmitted, along with programme schedules, simple games, and on the commercial ...
Get Newnes TV and Video Engineer's Pocket Book, 3rd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
