ANSWERS TO QUESTIONS Q1. THROUGH Q29.

2-63 ANSWERS TO QUESTIONS Q1. THROUGH Q29. A-1. Frequency and phase. A-2. Frequency-shift keying. A-3. Resistance to noise interference. A-4. Instantaneous frequency. A-5. As the ratio of the frequency deviation to the maximum frequency deviation allowable. A-6. The number of significant sidebands and the modulating frequency. A-7. By changing the reactance of an oscillator circuit in consonance with the modulating voltage. A-8. Collector-to-emitter capacitance. A-9. An LCR filter. A-10. Capacitance. A-11. Phase. A-12. A phase-shift network such as a variable resistor and capacitor in series. A-13. Cw and frequency-shift keying. A-14. Pulse modulation. A-15. Pulse-repetition time. A-16. Rest time. A-17. Peak power during a pulse averaged over pulse time plus rest time. A-18. Either a fixed spark gap that uses a trigger pulse to ionize the air between the contacts, or a rotary gap that is similar to a mechanical switch. A-19. Power source, a circuit for storing energy, a circuit for discharging the storage circuit, and a pulse transformer. A-20. Some characteristic of the pulses has to be varied. A-21. 2.5 times the highest modulating frequency. A-22. Both are susceptible to noise and interference. A-23. The time duration of the pulses or the time of occurrence of the pulses. A-24. Either, or both at the same time. A-25. It requires synchronization between the transmitter and receiver. A-26. A method of pulse modulation in which a modulating wave is used to frequency modulate a pulse-generating circuit.