What are three common oscillator circuits?

1. A Taft, Pierce, and negative feedback
2. B Pierce, Fenner, and Beane
3. C Taft, Hartley, and Pierce
4. D Colpitts, Hartley, and Pierce

What is a microphonic?

1. A An IC used for amplifying microphone signals
2. B Distortion caused by RF pickup on the microphone cable
3. C Changes in oscillator frequency caused by mechanical vibration
4. D Excess loading of the microphone by an oscillator

What is a phase-locked loop?

1. A An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
2. B An electronic circuit also known as a monostable multivibrator
3. C An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
4. D An electronic circuit consisting of a precision push-pull amplifier with a differential phase input

How is positive feedback supplied in a Colpitts oscillator?

1. A Through a tapped coil
2. B Through link coupling
3. C Through a capacitive divider
4. D Through a neutralizing capacitor

How is positive feedback supplied in a Pierce oscillator?

1. A Through a tapped coil
2. B Through link coupling
3. C Through a neutralizing capacitor
4. D Through a quartz crystal

Which of these functions can be performed by a phase-locked loop?

1. A Wide-band AF and RF power amplification
2. B Frequency synthesis and FM demodulation
3. C Photovoltaic conversion and optical coupling
4. D Comparison of two digital input signals and digital pulse counting

How can an oscillator's microphonic responses be reduced?

1. A Use NP0 capacitors
2. B Reduce noise on the oscillator's power supply
3. C Increase the gain
4. D Mechanically isolate the oscillator circuitry from its enclosure

Which of the following components can be used to reduce thermal drift in crystal oscillators?

1. A NP0 capacitors
2. B Toroidal inductors
3. C Wirewound resistors
4. D Non-inductive resistors

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital-to-analog converter, and a low-pass anti-alias filter?

1. A A direct digital synthesizer
2. B A hybrid synthesizer
3. C A phase-locked loop synthesizer
4. D A direct conversion synthesizer

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

1. A The phase relationship between a reference oscillator and the output waveform
2. B Amplitude values that represent the desired waveform
3. C The phase relationship between a voltage-controlled oscillator and the output waveform
4. D Frequently used receiver and transmitter frequencies

What are the major spectral impurity components of direct digital synthesizers?

1. A Broadband noise
2. B Digital conversion noise
3. C Spurious signals at discrete frequencies
4. D Harmonics of the local oscillator

Which of the following ensures that a crystal oscillator operates on the frequency specified by the crystal manufacturer?

1. A Provide the crystal with a specified parallel inductance
2. B Provide the crystal with a specified parallel capacitance
3. C Bias the crystal at a specified voltage
4. D Bias the crystal at a specified current

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

1. A Use a GPS signal reference
2. B Use a rubidium stabilized reference oscillator
3. C Use a temperature-controlled high Q dielectric resonator
4. D All these choices are correct