HamSandwich

Your callsign is showing. That's a good thing.

Study › Technician › T7A › T7A05

T7A05

PRACTICAL CIRCUITS · Station equipment: receivers, transceivers, transmitter amplifiers, RF preamplifiers, transverters; Basic radio circuit concepts and terminology: sensitivity, selectivity, mixers, oscillators, Push-To-Talk (PTT), VFO, modulation

T7A05T7A →

What is the name of a circuit that generates a signal at a specific frequency?

  1. AReactance modulator
  2. BPhase modulator
  3. CLow-pass filter
  4. DOscillator
Why An oscillator is the circuit that converts DC power into a repeating AC waveform at a chosen frequency, usually set by a crystal or an LC tank. Every transmitter and receiver needs one: the VFO that sets your operating frequency and the local oscillator that feeds a mixer are both oscillators. In short, it is the circuit that generates a signal at a specific frequency.
Watch out The modulator choices, reactance and phase, do not create a signal on their own; they take an existing carrier and vary it to impress audio or data onto it. A low-pass filter only removes frequencies above a cutoff, it generates nothing.
Oscillator = origin of the signal. Modulators change a signal, filters remove parts of it, only the oscillator makes one.
HamSandwich explanation, first draft. The question and answers are the NCVEC text.
← T7A04 All of T7A T7A06 →

The rest of T7A

  1. T7A01 Which term describes the ability of a receiver to detect the presence of a signal?
  2. T7A02 What is a transceiver?
  3. T7A03 Which of the following is used to convert a signal from one frequency to another?
  4. T7A04 Which term describes the ability of a receiver to discriminate between multiple signals?
  5. T7A05 What is the name of a circuit that generates a signal at a specific frequency?
  6. T7A06 What device converts the RF input and output of a transceiver to another band?
  7. T7A07 What is the function of a transceiver's PTT input?
  8. T7A08 Which of the following describes combining speech with an RF carrier signal?
  9. T7A09 What is the function of the switch which selects either SSB or CW-FM on some VHF power amplifiers?
  10. T7A10 What can be added to the output of a transceiver to increase the transmitted output power?
  11. T7A11 What is the function of the Variable Frequency Oscillator (VFO) circuit in a transceiver?
Baofeng BF-F8HP Pro Dual Band HandheldSponsored · View on Amazon →Baofeng UV-5R Dual Band Two Way RadioSponsored · View on Amazon →