interface cassette

The TV scope, introduced in the recent October issue, can no~ be completed. Two months ago the basic version was described in detail and the necessary circuits were given for converting a standard domestic television receiver into an oscilloscope - be it with limited capabilities. Last month the possibilities for extending the TV scope were discussed; in particular, the principles and advantages of a variable timebase and trigger facilities were explained. This third and final article in the series gives the necessary extension circuits. Although the basic version is an extremely useful tool when testing low-frequency circuits, its `big brother` offers vastly superior dii;play possibilities. Any signal within the frequency range of the scope (DC to 100 kHz) can be displayed as a clear and stable trace on the screen of any domestic TV receiver.