19 2-65.   How is the Q of a crystal determined? 1.  Type of cut used 2.  Type of holder used 3.  Accuracy of the grinding 4.  All of the above 2-66.   An oscillator that is turned ON for a specific period of time, then is turned OFF and remains OFF until required at a later time, is which of following types? 1.  LC 2.  Pierce 3.  Pulsed 4.  Crystal Figure 2F.—Oscillator circuit. IN ANSWERING QUESTIONS 2-67 THROUGH 2-70, REFER TO FIGURE 2F. 2-67.   What circuit is shown in the figure? 1.  Pierce oscillator 2.  Pulsed oscillator 3.  Colpitts oscillator 4.  Armstrong oscillator 2-68.   Sine waves are generated in the emitter circuit of Q1 during which of the following time periods of the input gate? 1.  T0 to T1 and T1 to T2 2.  T0 to T1 and T2 to T3 3.  T1 to T2 and T3 to T4 4.  T1 to T3 and T0 to T4 2-69.   The frequencies in the output are determined by what two circuit parameters? 1.  Input gate time and the time the circuit is turned OFF 2.  Output gate time and the time the circuit is turned ON 3.  Input gate time and the resonant frequency of the tank circuit 4.  Output gate time and the resonant frequency of the tank circuit, 2-70.   If the resonant frequency of the tank circuit were 5 megahertz and transistor Q1 were cut off for 500 microseconds, what maximum number of cycles of the tank frequency would be present in each pulse of the output? 1. 500 cycles 2.  1,500 cycles 3.  2,500 cycles 4.  3,500 cycles 2-71.   What is the fourth harmonic of a 2-megahertz signal? 1.  6 megahertz 2.  2 megahertz 3.  8 megahertz 4.  4 megahertz 2-72.   What is the highest multiplication factor normally used in frequency multipliers? 1.  One 2.  Two 3.  Three 4.  Four