Amateur Extra: Crystal Oscillator Frequency

Crystal Oscillator

Which of the following must be done to insure that a crystal oscillator provides the frequency specified by the crystal manufacturer? A. Provide the crystal with a specified parallel inductanceB. Provide the crystal with a specified parallel capacitanceC. Bias the crystal at a specified voltageD. Bias the crystal at a specified current A crystal oscillator … Read more

Sporadic E Propagation : Amateur Extra

Sporadic E Propagation

At what time of year is Sporadic E propagation most likely to occur? A. Around the solstices, especially the summer solsticeB. Around the solstices, especially the winter solsticeC. Around the equinoxes, especially the spring equinoxD. Around the equinoxes, especially the fall equinox Sporadic E Propagation refers to the phenomena where radio signals bounce off of … Read more

General: LSB Frequency Range

Modulated Radio Signal Frequency Spectrum

What frequency range is occupied by a 3 kHz LSB signal when the displayed carrier frequency is set to 7.178 MHz? A. 7.178 to 7.181 MHzB. 7.178 to 7.184 MHzC. 7.175 to 7.178 MHzD. 7.1765 to 7.1795 MHz LSB, or Lower Side Band, is a transmission mode where all of the transmitted signal exists to … Read more

Amateur Extra: Gray Code

Gray Code

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits? A. It increases security B. It has more possible states than simple binary C. It has more resolution than simple binary D. It facilitates error detection Firstly, what the heck is “Gray code” anyway? The reflected binary code … Read more

General: Class A Amplifier

Class A Amplifier

Which of the following is a characteristic of a Class A amplifier? A. Low standby power B. High Efficiency C. No need for bias D. Low distortion By definition, a Class A amplifier operates on 100% of the input signal.   Because of this, they are not particularly efficient or have low standby power.  “No need … Read more

Amateur Extra: Circular Polarization

Circular Polarization

What is meant by circularly polarized electromagnetic waves? A. Waves with an electric field bent into a circular shapeB. Waves with a rotating electric fieldC. Waves that circle the EarthD. Waves produced by a loop antenna To answer this we need to understand what’s going on inside an electromagnetic (or EM) wave.  In an EM … Read more