RAE CLASS A 2

What term describes a wide-bandwidth communications system in which the RF carrier varies according to some predetermined sequence?

• Amplitude compandor single sideband

• AMTOR

• Time-domain frequency modulation

• Spread-spectrum communication

What spread-spectrum communications technique alters the centre frequency of a conventional carrier many times per second in accordance with a pseudo-random list of channels?

• Frequency hopping

• Direct sequence

• Time-domain frequency modulation

• Frequency compandor spread-spectrum

What spread-spectrum communications technique uses a very fast binary bit stream to shift the phase of an RF carrier?

• Frequency hopping

• Direct sequence

• Binary phase-shift keying

• Phase compandor spread-spectrum

What controls the spreading sequence of an amateur spread-spectrum transmission?

• A frequency-agile linear amplifier

• A crystal-controlled filter linked to a high-speed crystal switching mechanism

• A binary linear feedback shift register

• A binary code which varies if propagation changes

Why are spread-spectrum communications so resistant to interference?

• Interfering signals are removed by a frequency-agile crystal filter

• Spread-spectrum transmitters use much higher power than conventional carrier-frequency transmitters

• Spread-spectrum transmitters can "hunt" for the best carrier frequency to use within a given RF spectrum

• Only signals using the correct spreading sequence are received

Why do spread-spectrum communications interfere so little with conventional channelized communications in the same band?

• A spread-spectrum transmitter avoids channels within the band which are in use by conventional transmitters

• Spread-spectrum signals appear only as low-level noise in conventional receivers

• Spread-spectrum signals change too rapidly to be detected by conventional receivers

• Special crystal filters are needed in conventional receivers to detect spread-spectrum signals

What is the term for the amplitude of the maximum positive excursion of a signal as viewed on an oscilloscope?

• Peak-to-peak voltage

• Inverse peak negative voltage

• RMS voltage

• Peak positive voltage

What is the easiest voltage amplitude dimension to measure by viewing a pure sine wave signal on an oscilloscope?

• Peak-to-peak voltage

• RMS voltage

• Average voltage

• DC voltage

What is the relationship between the peak-to-peak voltage and the peak voltage amplitude in a symmetrical waveform?

• 1:1

• 2:1

• 3:1

• 4:1

What input-amplitude parameter is valuable in evaluating the signal-handling capability of a Class A amplifier?

• Peak voltage

• RMS voltage

• An average reading power output meter

• Resting voltage