Mixed Deck — All Ham Radio General Class Test Topics Flashcards

What is the feed point impedance of a quarter-wave ground-plane antenna with the radials bent downward at 45 degrees?

Answer: About 50 ohms

Bending the radials of a ground-plane antenna downward to 45 degrees raises the feed point impedance to approximately 50 ohms, providing a good match to common coaxial cable.

What action is required if an RF exposure evaluation shows that MPE limits are exceeded at the property boundary?

Answer: Reduce power, change antenna, or implement other measures to bring exposure into compliance

Operators must take corrective action such as reducing power, raising the antenna, using a directional antenna, or reducing operating time to achieve compliance.

What is the primary advantage of a log-periodic dipole array (LPDA) antenna?

Answer: Wide bandwidth with consistent gain and impedance

An LPDA provides relatively constant gain and impedance characteristics across a wide frequency range.

What is the highest frequency limit of the General class phone segment on 40 meters?

Answer: 7.300 MHz

General class phone privileges on 40 meters run from 7.175 MHz up to 7.300 MHz, the top of the band.

What type of feed line loss increases significantly when the line is operated with high SWR?

Answer: Coaxial cable

Coaxial cable losses increase dramatically under high SWR conditions compared to open-wire feed lines.

What is the recommended minimum safe distance approach when working near an energized amateur antenna?

Answer: De-energize the antenna before climbing the tower or working nearby

The safest practice is to completely de-energize the antenna system before anyone works near it to eliminate all RF exposure risk.

An amateur station uses SSB voice with a typical duty cycle of about 20%. How does this affect the effective average power for RF exposure?

Answer: The effective average power is 20% of the PEP output

For SSB, a 20% duty cycle means the average power is approximately 20% of PEP, which is used in RF exposure calculations rather than peak power.

What may a ground loop in your station's audio connections manifest as?

Answer: You receive reports of “hum” on your station’s transmitted signal

When people report hearing a "hum" in your station's transmitted signal, a ground loop may be the cause. Ground loops frequently cause interference and noise, and in rare situations, they could even put users at danger for electric shock.

What is the approximate MPE power density limit for the general public at 146 MHz?

Answer: 0.2 mW/cm²

At 146 MHz (VHF), the uncontrolled (general public) MPE limit is approximately 0.2 mW/cm², which is five times lower than the 1 mW/cm² occupational limit.

A General class licensee wants to use RTTY on 40 meters. What portion of the band is permitted?

Answer: 7.025–7.125 MHz

General class operators may use RTTY/data on 40 meters from 7.025 to 7.125 MHz.

What is the safest way to discharge a high-voltage capacitor before handling?

Answer: Use a resistor in series with an insulated probe to bleed the charge slowly

Using a resistor in series with an insulated probe bleeds the capacitor charge slowly and safely without creating a damaging current spike.

What does the term 'lid' refer to in amateur radio slang?

Answer: A poor or inconsiderate operator

'Lid' is slang for an inexperienced or discourteous amateur radio operator.

What is the purpose of sending 'QRL?' before transmitting on an HF frequency?

Answer: To ask if the frequency is in use before transmitting

QRL? is the Q-code query meaning 'Is this frequency in use?' — a courtesy check to avoid interfering with an ongoing contact.

An amateur operator is setting up an HF station and finds the SWR is 3:1 on their desired frequency. Which of the following is the most likely consequence of operating with this high SWR?

Answer: The transceiver may reduce its output power to protect its final amplifier circuits.

A high SWR indicates a significant impedance mismatch, causing a portion of the transmitter's power to be reflected back down the feed line. Modern solid-state transceivers have protective circuitry that detects high SWR and automatically reduces the output power to prevent the reflected power from damaging the final amplifier transistors. While some power is lost and the system is inefficient, the primary immediate effect is often this protective power reduction.

In a common-emitter transistor amplifier, what is the phase relationship between the input and output signals?

Answer: The output is 180 degrees out of phase with the input

A common-emitter amplifier inverts the signal, producing a 180-degree phase shift between input and output.

Which of the following best practices for net management among amateurs?

Answer: Have a backup frequency in case of interference or poor conditions

In order to handle the net effectively, it is a good amateur practice to have a backup frequency.

What is the Radio Amateur Civil Emergency Service (RACES)?

Answer: A part of amateur radio designated for use during civil emergencies under government direction

RACES is a part of amateur radio authorized by FCC Part 97 to provide communications for civil defense authorities during declared emergencies.

What is the meaning of the term 'pileup' in HF DX operating?

Answer: Many stations calling a rare DX station simultaneously

A pileup occurs when many amateur stations simultaneously try to contact a rare or sought-after DX station.

What does the FCC require regarding station identification when using a phone emission?

Answer: ID must be given in English at the beginning and end of each contact and every 10 minutes

Part 97 requires phone stations to identify in English (or CW) at the beginning and end of contacts and at least every 10 minutes during a contact.

What is the voluntary band plan purpose for the segment 14.225 to 14.150 MHz on 20 meters?

Answer: SSB voice operations

The segment from 14.225 to 14.350 MHz on 20 meters is primarily used for SSB voice operations by General class operators.