Technician T4A: Setting up your station: power, meters and computers
These are the 12 official questions in group T4A of the 2026–2030 Technician question pool, with the correct answer marked and a plain-English explanation of why it's right. The real exam asks one question from this group.
- T4A01Question 1
Which of the following is an appropriate power supply rating for a typical 50-watt output mobile FM transceiver?
- A24.0 volts at 4 amperes
- B13.8 volts at 4 amperes
- C24.0 volts at 12 amperes
- D13.8 volts at 12 amperes Correct
Why: At 13.8 volts, a 50-watt radio draws roughly 10 to 12 amps on transmit, so 12 amps is a good supply rating.
- T4A02Question 2
Which of the following should be considered when selecting an accessory SWR meter?
- AThe frequency and power level at which the measurements will be made Correct
- BThe distance that the meter will be located from the antenna
- CThe maximum SWR anticipated on the transmission line
- DThe ability of the meter to compensate for a poor transmission line match to the antenna
Why: SWR meters are made for certain frequency ranges and power levels, so match the meter to how you'll use it.
- T4A03Question 3
Why are short, heavy-gauge wires used for a transceiver’s DC power connection?
- ATo minimize voltage drop when transmitting Correct
- BTo provide a close match to the power supply output impedance
- CTo avoid RF interference
- DTo minimize radiative losses in the power cable
Why: Short, heavy wires have low resistance, so the voltage drops less under the high transmit current.
- T4A04Question 4
How are the audio input and output of a transceiver connected in a station configured to operate using FT8?
- ATo a computer running a terminal program and connected to a terminal node controller unit
- BTo the audio output and input of a computer running FT8 software Correct
- CTo an FT8 conversion unit, a keyboard, and a computer monitor
- DTo a computer connected to the FT8converter.com website
Why: The radio's audio output goes to the computer's input and the computer's output goes to the radio's input, so FT8 software can hear and send.
- T4A05Question 5
Where should an RF power meter be installed?
- AIn the feed line, between the transmitter and antenna Correct
- BAt the power supply output
- CIn parallel with the push-to-talk line and the antenna
- DIn the power supply cable, as close as possible to the radio
Why: A power meter goes in the feed line between the transmitter and the antenna.
- T4A06Question 6
What signals are used in a computer-radio interface for digital mode operation?
- AReceive and transmit mode, status, and location
- BAntenna and RF power
- CReceive audio, transmit audio, and transmitter keying Correct
- DNMEA GPS location and DC power
Why: Digital modes need receive audio, transmit audio and a way to key the transmitter.
- T4A07Question 7
Which of the following is one of the connections required between a computer and a transceiver to operate digital modes?
- AComputer “line out” to transceiver push-to-talk
- BComputer “line in” to transceiver push-to-talk
- CComputer “line in” to transceiver speaker connector Correct
- DComputer “line out” to transceiver speaker connector
Why: The computer's line-in gets receive audio from the radio's speaker jack.
- T4A08Question 8
Which of the following conductors is preferred for bonding at RF?
- ACopper braid removed from coaxial cable
- BCopper-clad steel wire
- CTwisted-pair cable
- DFlat copper strap Correct
Why: Flat copper strap has low inductance, so it's the best bonding conductor at RF.
- T4A09Question 9
How can you determine the length of time that equipment can be powered from a battery?
- ADivide the watt-hour rating of the battery by the peak power consumption of the equipment
- BDivide the battery ampere-hour rating by the average current draw of the equipment Correct
- CMultiply the watts per hour consumed by the equipment by the battery power rating
- DMultiply the square of the current rating of the battery by the input resistance of the equipment
Why: Divide the battery's amp-hour rating by the average current draw to get hours of run time.
- T4A10Question 10
What function does a digital mode hotspot perform for nearby transceivers?
- ACommunication with a digital voice or data network Correct
- BFT8 digital communications via AFSK using a smartphone connected to the internet
- CRTTY encoding and decoding without a computer
- DHigh-speed digital communications for meteor scatter
Why: A hotspot links nearby radios to a digital voice or data network over the internet.
- T4A11Question 11
Where should the negative power return of a mobile transceiver be connected in a vehicle?
- AAt the 12-volt battery chassis ground Correct
- BTo the shell of the power connector
- CTo any metal part of the vehicle
- DThrough the transceiver’s mounting bracket
Why: Connect the negative lead at the battery's chassis ground connection.
- T4A12Question 12
What is an electronic keyer?
- AA device for switching antennas from transmit to receive
- BA device for voice activated switching from receive to transmit
- CA device that assists in manual sending of Morse code Correct
- DAn interlock to prevent unauthorized use of a radio
Why: An electronic keyer helps you send Morse code by forming dots and dashes as you work the paddles.