| 摘要 |
<p>PURPOSE:To improve operation remarkabley by make it possible to fulfill reproductive spot knocking with a cathode-ray tube fitted by making the intermediate potential of a spot knocking power voltage equal to the earth potential. CONSTITUTION:The intermediate potential of high spot knocking voltage 13 is grounded. In the case spot knocking is required is consequence of defective dielectric-strength characteristics of cathode-ray tube 1 after the fabrication of the receiver, cathode-ray tube 1, deflecting yoke 6 and purity magnet 7 all remain fitted, socket 9, anode cap 11, etc., are detached, and spot knocking anode cap 14 and socket 15 are connected instead. Further, the applied voltage is made one to three times as high as the maximum rated voltage of cathode-ray tube 1, but positive voltage side 13a is so set that no discharge will occur among yoke 6 close to the earth potential, external conductive film 12 and cap 14, thereby setting the voltage to a value required for spot knocking by selecting the voltage at negative voltage side 13b.</p> |
