REVIEW QUESTIONS

Each electron gun is electrostatically focused by a common grid voltage. In other words, each gun has its own electrode, but all three are connected together requiring only one grid voltage. The three electron beams scan the screen and are controlled by the deflection yoke mounted externally around the neck of the tube. As the three beams scan the phosphor screen horizontally and vertically in the standard scanning pattern, the dot triads light up according to the video input signals (fig. 5-34). The purifying coil produces a magnetic field within the tube that aligns the electron beams parallel to the neck of the tube. Rotating the purifying coil adjusts the electron beams so they strike their respective color dots without striking neighboring dots. When this adjustment is made for the red dots, the other two electron beams are aligned as well. The high-voltage anode is a metallic ring around the tube. The field neutralizing coil aids color purity at the outer edges of the picture tube. A metal shield, called a mu-metal shield, is placed around the bell of the tube to prevent stray magnetic fields from affecting the electron beams. Q1. Q2. Q3. Q4. Q5. Q6. Q7. Q8. Q9. Q10. Q11. Q12. REVIEW QUESTIONS Which heading indicator displays the most information? Are the three control boxes in the HSI group interchangeable between the stations? On the BDHI, what is the lubber index? What does HUD stand for? What does TDS stand for? What is a combiner, as used with the HUD system? How many different dc voltages are used in the HUD unit? In the HUD system how many basic modes of operation are there? The SENSO ARU receives inputs from what source? What is another term for a camera tube? What process is referred to as scanning? How many elements are contained in a standard television signal? 5-27