Antenna Gain dBi vs. dBd

Effective Radiated Power

How does antenna gain stated in dBi compare to gain stated in dBd for the same antenna? A. dBi gain figures are 2.15 dB lower than dBd gain figuresB. dBi gain figures are 2.15 dB higher than dBd gain figuresC. dBi gain figures are the same as the square root of dBd gain figures multiplied … Read more

Determine Maximum Usable Frequency

Determine Maximum Usable Frequency

What is a reliable way to determine if the MUF is high enough to support skip propagation between your station and a distant location on frequencies between 14 and 30 MHz? A. Listen for signals from an international beacon in the frequency range you plan to useB. Send a series of dots on the band … Read more

Estimating Maximum Permissible Exposure

Estimating Maximum Permissible Exposure

Which of the following properties is important in estimating whether an RF signal exceeds the maximum permissible exposure (MPE)? A. Its duty cycleB. Its frequencyC. Its power densityD. All these choices are correct [G0A02] Let’s look at each possible answer individually, and then we’ll decide which is correct. A. Its duty cycle. Duty Cycle refers … Read more

What unit is used to measure reactance?

unit of reactance

What unit is used to measure reactance? A. FaradB. OhmC. AmpereD. Siemens This is a really easy question, when you understand what reactance is exactly. Reactance is one part of what we call Impedance. The problem is that impedance is in mathematical terms, a complex number. That means there’s a “real” part, and an “imaginary” … Read more

Binary States

How many states does a 3-bit binary counter have?

Ah a little down one of the side paths of amateur radio for this question from the General Class exam pool. How many states does a 3-bit binary counter have? A. 3B. 6C. 8D. 16 The answer depends on us knowing how to count in binary. Essentially the question is asking us what the maximum … 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

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

General: Quad Antennas

Quad Antenna

Approximately how long is each side of the reflector element of a quad antenna? A. Slightly less than 1/4 wavelength B. Slightly more than 1/4 wavelength C. Slightly less than 1/2 wavelength D. Slightly more than 1/2 wavelength So lets look at what a “quad antenna” entails.  As you might have guessed from the name, … Read more

General: Sine Wave Oscillators

RC phase shift oscillator

What are the basic components of virtually all sine wave oscillators? A. An amplifier and a dividerB. A frequency multiplier and a mixerC. A circulator and a filter operating in a feed-forward loopD. A filter and an amplifier operating in a feedback loop To answer this question, lets look at what makes up a sine … Read more

General: Uses For An Antenna Analyzer

What is a use for an antenna analyzer other than measuring the SWR of an antenna system? A. Measuring the front to back ratio of an antennaB. Measuring the turns ratio of a power transformerC. Determining the impedance of an unknown or unmarked coaxial cableD. Determining the gain of a directional antenna Well, you’re not … Read more