Technician exam: practical circuits and equipment
Receivers, transmitters, transceivers, amplifiers, meters and troubleshooting. 44 questions, 10 at a time, starting with ones you haven't seen.
Rules to remember10 key practical circuits and equipment rulesShow the rules
- Selectivity is a receiver's ability to pick out the wanted signal while rejecting others on nearby frequencies. (p. 51)
- An RF power amplifier placed after the transceiver boosts its output to a higher transmitted power. (p. 52)
- A band-reject filter tuned to the FM broadcast band removes that strong signal before it reaches the 2-meter receiver. (p. 54)
- An antenna analyzer sweeps frequencies and shows SWR or impedance, revealing where the antenna is resonant. (p. 55)
- A dummy load is a 50-ohm resistor that does not behave like a coil, mounted so the heat from the absorbed power can escape. (p. 55)
- Electric potential is voltage, and it is measured with a voltmeter. (p. 57)
- To measure current, the meter must be placed in series so the current passes through it. (p. 57)
- An ammeter measures electric current, typically in amperes. (p. 57)
- An ohmmeter sends a small known current through the part and measures the voltage across it, then uses Ohm's law to find resistance. (p. 58)
- Always switch off the circuit before measuring resistance; live voltage gives false readings and can damage the ohmmeter. (p. 59)
Taken from the explanations to checked practice questions; page numbers link to the official handbook.
Sample practical circuits and equipment questions
1.What does a typical RF dummy load consist of?
- AA 50-ohm non-inductive resistor mounted on a heat sink
- BA 50-ohm inductive reactance mounted in a shielded enclosure
- CA low-voltage power supply and an AC relay
- DA low-voltage power supply and a DC relay
Show the answer
✓ A. A 50-ohm non-inductive resistor mounted on a heat sink
A dummy load is a 50-ohm resistor that does not behave like a coil, mounted so the heat from the absorbed power can escape.
2.What should be the first step to resolve non-fiber optic cable TV interference caused by your amateur radio transmission?
- AAdd a preamplifier to the TV antenna input
- BAdd a low-pass filter to the TV antenna input
- CBe sure all TV feed line coaxial connectors are installed properly
- DAdd a high-pass filter to the TV antenna input
Show the answer
✓ C. Be sure all TV feed line coaxial connectors are installed properly
Most cable TV interference gets in through loose or poor connectors, so checking that every coax connector is installed properly comes first.
3.Which of the following can reduce interference to a 2-meter band transceiver from a nearby commercial FM station?
- AInstalling a band-reject filter
- BUsing double-shielded coaxial cable
- CInstalling bypass capacitors on the microphone cable
- DInstalling an RF preamplifier
Show the answer
✓ A. Installing a band-reject filter
A band-reject filter tuned to the FM broadcast band removes that strong signal before it reaches the 2-meter receiver.
4.Which of the following describes combining speech with an RF carrier signal?
- ALow-pass filtering
- BImpedance matching
- COscillation
- DModulation
Show the answer
✓ D. Modulation
Modulation is the process of putting information such as speech onto an RF carrier so it can be transmitted.