General · G8
SIGNALS AND EMISSIONS
Modulation and digital modes in more depth: bandwidth, SSB and CW characteristics, and the growing set of digital modes General-class operators use on HF.
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42 questions across 3 groups
Group G8A
- G8A01How is direct binary FSK modulation generated?
- G8A02What is the name of the process that changes the phase angle of an RF signal to convey information?
- G8A03What is the name of the process that changes the instantaneous frequency of an RF wave to convey information?
- G8A04What emission is produced by a reactance modulator connected to a transmitter RF amplifier stage?
- G8A05What type of modulation varies the instantaneous power level of the RF signal?
- G8A06Which of the following is characteristic of QPSK31?
- G8A07Which of the following phone emissions uses the narrowest bandwidth?
- G8A08Which of the following is an effect of overmodulation?
- G8A09What type of modulation is used by FT8?
- G8A10What is meant by the term “flat-topping,” when referring to an amplitude-modulated phone signal?
- G8A11What is the modulation envelope of an AM signal?
- G8A12What is QPSK modulation?
- G8A13What is a link budget?
- G8A14What is link margin?
Group G8B
- G8B01Which mixer input is varied or tuned to convert signals of different frequencies to an intermediate frequency (IF)?
- G8B02What is the term for interference from a signal at twice the IF frequency from the desired signal?
- G8B03What is another term for the mixing of two RF signals?
- G8B04What is the stage in a VHF FM transmitter that generates a harmonic of a lower frequency signal to reach the desired operating frequency?
- G8B05Which intermodulation products are closest to the original signal frequencies?
- G8B06What is the total bandwidth of an FM phone transmission having 5 kHz deviation and 3 kHz modulating frequency?
- G8B07What is the frequency deviation for a 12.21 MHz reactance modulated oscillator in a 5 kHz deviation, 146.52 MHz FM phone transmitter?
- G8B08Why is it important to know the duty cycle of the mode you are using when transmitting?
- G8B09Why is it good to match receiver bandwidth to the bandwidth of the operating mode?
- G8B10What is the relationship between transmitted symbol rate and bandwidth?
- G8B11What combination of a mixer’s Local Oscillator (LO) and RF input frequencies is found in the output?
- G8B12What process combines two signals in a non-linear circuit to produce unwanted spurious outputs?
- G8B13Which of the following is an odd-order intermodulation product of frequencies F1 and F2?
Group G8C
- G8C02Which digital mode is used as a low-power beacon for assessing HF propagation?
- G8C03What part of a packet radio frame contains the routing and handling information?
- G8C04Which of the following describes Baudot code?
- G8C05In an ARQ mode, what is meant by a NAK response to a transmitted packet?
- G8C06What action results from a failure to exchange information due to excessive transmission attempts when using an ARQ mode?
- G8C07Which of the following narrow-band digital modes can receive signals with very low signal-to-noise ratios?
- G8C08Which of the following statements is true about PSK31?
- G8C09Which is true of mesh network microwave nodes?
- G8C10How does forward error correction (FEC) allow the receiver to correct data errors?
- G8C11How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified?
- G8C12Which type of code is used for sending characters in a PSK31 signal?
- G8C13What is indicated on a waterfall display by one or more vertical lines on either side of a data mode or RTTY signal?
- G8C14Which of the following describes a waterfall display?
- G8C15What does an FT8 signal report of +3 mean?
- G8C16Which of the following provide digital voice modes?