Amateur Radio for Smart People
K5HRA 
What causes spin fading when referring to satellite signals? [T8B09] A. Circular polarized noise interference radiated from the sun B. Rotation of the satellite and its antennas C. Doppler shift of the received signal D. Interfering signals within the satellite uplink band Well, to start with, I suppose we should define “spin fading.” Spin fading … Read more
What do the two numbers represent that are used to define a point on a graph using rectangular coordinates? [E5C11] A. The magnitude and phase of the point B. The sine and cosine values C. The coordinate values along the horizontal and vertical axes D. The tangent and cotangent values This might seem like a … Read more
What is the turns ratio of a transformer used to match an audio amplifier having 600 ohm output impedance to a speaker having 4 ohm impedance? [G5C07] A. 12.2 to 1 B. 24.4 to 1 C. 150 to 1 D. 300 to 1 This is a simple ratio type equation, almost. The equation for solving … Read more
What is the ability to store energy in a magnetic field called? [T5C03] A. Admittance B. Capacitance C. Resistance D. Inductance Here we have another example of a “definition” type of question. The answer is D. Inductance. A device that stores a magnetic field is called an inductor. So if you can remember the correlation, … Read more
What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors? [E5D09] A. It is dissipated as heat in the circuit B. It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated C. It is dissipated as kinetic energy in the circuit D. It … Read more
Why is high input impedance desirable for a voltmeter? [G4B05] A. It improves the frequency response B. It decreases battery consumption in the meter C. It improves the resolution of the readings D. It decreases the loading on circuits being measured Remember that impedance is the property of a circuit that prevents current from moving … Read more
What should be done to insure that voice message traffic containing proper names and unusual words are copied correctly by the receiving station? [T2C03] A. The entire message should be repeated at least four times B. Such messages must be limited to no more than 10 words C. Such words and terms should be spelled … Read more
What is the typical output impedance of an integrated circuit op-amp? [E7G15] A. Very low B. Very high C. 100 ohms D. 1000 ohms A A. Very low output impedance is a property of an IC op-amp. In an ideal case, it would be zero. But of course that’s never possible. In reality, the behavior … Read more
What is the frequency deviation for a 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52MHz FM phone transmitter? [G8B07] A. 101.75 Hz B. 416.7 Hz C. 5 kHz D. 60 kHz Whoa, what? Guess what, dust off that calculator, because here’s where it starts to get mathy. This question is also terribly … Read more
Which of the following describes a simple dipole mounted so the conductor is parallel to the Earth’s surface? [T9A03] A. A ground wave antenna B. A horizontally polarized antenna C. A rhombic antenna D. A vertically polarized antenna Lets recall what we mean when we talk about an electromagnetic field being “polarized.” The direction of … Read more