4. What troubles were encountered in the earlier forms of granular carbon transmitters and how were they overcome?
5. What limits the current-carrying capacity of the transmitter? How may this capacity be increased?
6. State in what kind of transmitters a maximum degree of sensitiveness is desirable.
7. Show the conventional symbols for transmitters.
8. Describe a telephone receiver.
9. Sketch a Western Electric receiver and point out its deficiencies.
10. Make a diagram of the Kellogg receiver.
11. Describe the direct-current receiver of the Automatic Electric Company.
12. Describe and sketch the Dean receiver.
13. Show the conventional symbols of a receiver.