2023 General pool
50 / 430 questions need explanations
All explanations are written and maintained by ordinary users like you! Please help us finish the explanations in this pool.
What is the purpose of an antenna tuner?
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Reduce the SWR in the feed line to the antenna (32% chose this)
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Reduce the power dissipation in the feedline to the antenna (10% chose this)
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Increase power transfer from the transmitter to the feed line (19% chose this)
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All these choices are correct (39% chose this)
Which intermodulation products are closest to the original signal frequencies?
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Second harmonics (46% chose this)
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Even-order (10% chose this)
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Odd-order (27% chose this)
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Intercept point (17% chose this)
Which of the following is an odd-order intermodulation product of frequencies F1 and F2?
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5F1-3F2 (16% chose this)
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3F1-F2 (18% chose this)
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2F1-F2 (25% chose this)
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All these choices are correct (41% chose this)
What is the term for the inverse of impedance?
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Conductance (59% chose this)
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Susceptance (2% chose this)
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Reluctance (14% chose this)
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Admittance (25% chose this)
What does an FT8 signal report of +3 mean?
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The signal is 3 times the noise level of an equivalent SSB signal (19% chose this)
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The signal is S3 (weak signals) (8% chose this)
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The signal-to-noise ratio is equivalent to +3dB in a 2.5 kHz bandwidth (33% chose this)
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The signal is 3 dB over S9 (40% chose this)
When operating a station in South America by remote control over the internet from the US, what regulations apply?
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Those of both the remote station’s country and the FCC (37% chose this)
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Those of the remote station’s country and the FCC’s third-party regulations (21% chose this)
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Only those of the remote station’s country (26% chose this)
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Only those of the FCC (16% chose this)
What output is produced by a balanced modulator?
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Frequency modulated RF (34% chose this)
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Audio with equalized frequency response (26% chose this)
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Audio extracted from the modulation signal (6% chose this)
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Double-sideband modulated RF (34% chose this)
What is a typical upper frequency limit for low SWR operation of 50-ohm BNC connectors?
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50 MHz (21% chose this)
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500 MHz (42% chose this)
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4 GHz (33% chose this)
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40 GHz (4% chose this)
What happens when inductive and capacitive reactance are equal in a series LC circuit?
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Resonance causes impedance to be very high (30% chose this)
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Impedance is equal to the geometric mean of the inductance and capacitance (15% chose this)
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Resonance causes impedance to be very low (34% chose this)
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Impedance is equal to the arithmetic mean of the inductance and capacitance (21% chose this)
What effect can strong signals from nearby transmitters have on an antenna analyzer?
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Desensitization which can cause intermodulation products which interfere with impedance readings (2% chose this)
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Received power that interferes with SWR readings (39% chose this)
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Generation of harmonics which interfere with frequency readings (4% chose this)
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All these choices are correct (56% chose this)
Which is true of mesh network microwave nodes?
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Having more nodes increases signal strengths (5% chose this)
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If one node fails, a packet may still reach its target station via an alternate node (59% chose this)
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Links between two nodes in a network may have different frequencies and bandwidths (24% chose this)
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More nodes reduce overall microwave out of band interference (11% chose this)
How is a product detector used?
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Used in test gear to detect spurious mixing products (19% chose this)
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Used in transmitter to perform frequency multiplication (9% chose this)
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Used in an FM receiver to filter out unwanted sidebands (21% chose this)
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Used in a single sideband receiver to extract the modulated signal (51% chose this)
What is QPSK modulation?
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Modulation using quasi-parallel to serial conversion to reduce bandwidth (7% chose this)
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Modulation using quadra-pole sideband keying to generate spread spectrum signals (20% chose this)
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Modulation using Fast Fourier Transforms to generate frequencies at the first, second, third, and fourth harmonics of the carrier frequency to improve noise immunity (22% chose this)
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Modulation in which digital data is transmitted using 0-, 90-, 180- and 270-degrees phase shift to represent pairs of bits (52% chose this)
What is the term for interference from a signal at twice the IF frequency from the desired signal?
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Quadrature response (17% chose this)
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Image response (48% chose this)
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Mixer interference (22% chose this)
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Intermediate interference (13% chose this)
What occurs in an LC circuit at resonance?
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Current and voltage are equal (30% chose this)
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Resistance is cancelled (9% chose this)
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The circuit radiates all its energy in the form of radio waves (11% chose this)
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Inductive reactance and capacitive reactance cancel (49% chose this)
Which of the following is good practice when choosing a transmitting frequency to answer a station calling CQ using FT8?
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Always call on the station’s frequency (49% chose this)
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Call on any frequency in the waterfall except the station’s frequency (0% chose this)
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Find a clear frequency during the same time slot as the calling station (13% chose this)
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Find a clear frequency during the alternate time slot to the calling station (39% chose this)
What letter is used to represent reactance?
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Z (30% chose this)
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X (46% chose this)
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B (5% chose this)
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Y (20% chose this)
When is an analog multimeter preferred to a digital multimeter?
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When testing logic circuits (6% chose this)
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When high precision is desired (22% chose this)
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When measuring the frequency of an oscillator (28% chose this)
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When adjusting circuits for maximum or minimum values (45% chose this)
Which of the following is a way to determine current propagation on a desired band from your station?
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Use a network of automated receiving stations on the internet to see where your transmissions are being received (45% chose this)
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Check the A-index (6% chose this)
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Send a series of dots and listen for echoes (8% chose this)
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All these choices are correct (42% chose this)
What is the purpose of delaying RF output after activating a transmitter’s keying line to an external amplifier?
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To prevent key clicks on CW (7% chose this)
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To prevent transient overmodulation (14% chose this)
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To allow time for the amplifier to switch the antenna between the transceiver and the amplifier output (54% chose this)
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To allow time for the amplifier power supply to reach operating level (25% chose this)
How does a liquid crystal display compare to an LED display?
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Higher contrast in high ambient lighting (62% chose this)
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Wider dynamic range (6% chose this)
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Higher power consumption (18% chose this)
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Shorter lifetime (14% chose this)
How often may RACES training drills and tests be routinely conducted without special authorization?
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No more than 1 hour per month (16% chose this)
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No more than 2 hours per month (18% chose this)
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No more than 1 hour per week (47% chose this)
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No more than 2 hours per week (19% chose this)
When may third-party messages be transmitted via remote control?
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Under any circumstances in which third party messages are permitted by FCC rules (46% chose this)
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Under no circumstances except for emergencies (33% chose this)
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Only when the message is intended for licensed radio amateurs (14% chose this)
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Only when the message is intended for third parties in areas where licensing is controlled by the FCC (7% chose this)
What procedure may be used by Volunteer Monitors to localize a station whose continuous carrier is holding a repeater on in their area?
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Compare vertical and horizontal signal strengths on the input frequency (3% chose this)
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Compare beam headings on the repeater input from their home locations with that of other Volunteer Monitors (48% chose this)
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Compare signal strengths between the input and output of the repeater (7% chose this)
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All these choices are correct (42% chose this)
Which parameter affects receiver sensitivity?
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Input amplifier gain (29% chose this)
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Demodulator stage bandwidth (9% chose this)
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Input amplifier noise figure (4% chose this)
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All these choices are correct (59% chose this)
What is the output voltage if an input signal is applied to the secondary winding of a 4:1 voltage step-down transformer instead of the primary winding?
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The input voltage is multiplied by 4 (60% chose this)
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The input voltage is divided by 4 (34% chose this)
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Additional resistance must be added in series with the primary to prevent overload (3% chose this)
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Additional resistance must be added in parallel with the secondary to prevent overload (2% chose this)
Where should the station’s lightning protection ground system be located?
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As close to the station equipment as possible (37% chose this)
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Outside the building (61% chose this)
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Next to the closest power pole (0% chose this)
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Parallel to the water supply line (2% chose this)
Which HF bands have segments exclusively allocated to Amateur Extra licensees?
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All HF bands (28% chose this)
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80 meters, 40 meters, 20 meters, and 15 meters (34% chose this)
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All HF bands except 160 meters and 10 meters (17% chose this)
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60 meters, 30 meters, 17 meters, and 12 meters (21% chose this)
What action results from a failure to exchange information due to excessive transmission attempts when using an ARQ mode?
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The checksum overflows (6% chose this)
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The connection is dropped (69% chose this)
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Packets will be routed incorrectly (19% chose this)
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Encoding reverts to the default character set (6% chose this)
Which of the following describes Winlink?
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An amateur radio wireless network to send and receive email on the internet (26% chose this)
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A form of Packet Radio (5% chose this)
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A wireless network capable of both VHF and HF band operation (5% chose this)
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All of the above (64% chose this)
What is a link budget?
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The financial costs associated with operating a radio link (10% chose this)
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The sum of antenna gains minus system losses (18% chose this)
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The sum of transmit power and antenna gains minus system losses as seen at the receiver (62% chose this)
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The difference between transmit power and receiver sensitivity (10% chose this)
What is VARA?
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A low signal-to-noise digital mode used for EME (moonbounce) (7% chose this)
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A digital protocol used with Winlink (68% chose this)
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A radio direction finding system used on VHF and UHF (16% chose this)
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DX spotting system using a network of software defined radios (9% chose this)
Why are signal reports typically exchanged at the beginning of an HF contact?
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To allow each station to operate according to conditions (68% chose this)
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To be sure the contact will count for award programs (7% chose this)
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To follow standard radiogram structure (12% chose this)
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To allow each station to calibrate their frequency display (14% chose this)
Which of the following is good amateur practice for net management?
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Always use multiple sets of phonetics during check-in (4% chose this)
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Have a backup frequency in case of interference or poor conditions (54% chose this)
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Transmit the full net roster at the beginning of every session (8% chose this)
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All these choices are correct (34% chose this)
Which of these functions is performed by software in a software-defined radio (SDR)?
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Filtering (10% chose this)
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Detection (0% chose this)
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Modulation (8% chose this)
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All these choices are correct (82% chose this)
Where should lightning arrestors be located?
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Where the feed lines enter the building (67% chose this)
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On the antenna, opposite the feed point (11% chose this)
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In series with each ground lead (13% chose this)
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At the closest power pole ground electrode (8% chose this)
In an ARQ mode, what is meant by a NAK response to a transmitted packet?
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Request retransmission of the packet (73% chose this)
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Packet was received without error (13% chose this)
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Receiving station connected and ready for transmissions (11% chose this)
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Entire file received correctly (4% chose this)
What is link margin?
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The opposite of fade margin (4% chose this)
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The difference between received power level and minimum required signal level at the input to the receiver (72% chose this)
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Transmit power minus receiver sensitivity (9% chose this)
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Receiver sensitivity plus 3 dB (16% chose this)
What precaution should be taken when connecting a solar panel to a lithium iron phosphate battery?
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Ground the solar panel outer metal framework (11% chose this)
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Ensure the battery is placed terminals-up (3% chose this)
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A series resistor must be in place (20% chose this)
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The solar panel must have a charge controller (66% chose this)
When operating a US station by remote control from outside the country, what license is required of the control operator?
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A US operator/primary station license (51% chose this)
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Only an appropriate US operator/primary license and a special remote station permit from the FCC (23% chose this)
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Only a license from the foreign country, as long as the call sign includes identification of portable operation in the US (12% chose this)
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A license from the foreign country and a special remote station permit from the FCC (13% chose this)
On which HF and/or MF amateur bands are there portions where General class licensees cannot transmit?
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60 meters, 30 meters, 17 meters, and 12 meters (24% chose this)
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160 meters, 60 meters, 15 meters, and 12 meters (24% chose this)
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80 meters, 40 meters, 20 meters, and 15 meters (40% chose this)
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80 meters, 20 meters, 15 meters, and 10 meters (11% chose this)
What must you do if your station fails to meet the FCC RF exposure exemption criteria?
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Perform an RF Exposure Evaluation in accordance with FCC OET Bulletin 65 (74% chose this)
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Contact the FCC for permission to transmit (2% chose this)
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Perform an RF exposure evaluation in accordance with World Meteorological Organization guidelines (9% chose this)
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Use an FCC-approved band-pass filter (16% chose this)
Which of the following provide digital voice modes?
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WSPR, MFSK16, and EasyPAL (6% chose this)
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FT8, FT4, and FST4 (12% chose this)
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Winlink, PACTOR II, and PACTOR III (14% chose this)
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DMR, D-STAR, and SystemFusion (68% chose this)
Which of the following is a common use of the dual-VFO feature on a transceiver?
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To allow transmitting on two frequencies at once (11% chose this)
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To permit full duplex operation -- that is, transmitting and receiving at the same time (8% chose this)
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To transmit on one frequency and listen on another (74% chose this)
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To improve frequency accuracy by allowing variable frequency output (VFO) operation (6% chose this)
What is another name for a Winlink Remote Message Server?
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Terminal Node Controller (21% chose this)
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Gateway (73% chose this)
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RJ-45 (3% chose this)
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Printer/Server (3% chose this)
What is meant by the term “critical frequency” at a given incidence angle?
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The highest frequency which is refracted back to Earth (79% chose this)
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The lowest frequency which is refracted back to Earth (8% chose this)
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The frequency at which the signal-to-noise ratio approaches unity (11% chose this)
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The frequency at which the signal-to-noise ratio is 6 dB (2% chose this)
What is the primary purpose of an Amateur Radio Emergency Data Network (AREDN) mesh network?
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To provide FM repeater coverage in remote areas (5% chose this)
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To provide real time propagation data by monitoring amateur radio transmissions worldwide (16% chose this)
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To provide high-speed data services during an emergency or community event (79% chose this)
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To provide DX spotting reports to aid contesters and DXers (0% chose this)
How much change in signal strength is typically represented by one S unit?
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6 dB (77% chose this)
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12 dB (11% chose this)
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15 dB (8% chose this)
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18 dB (5% chose this)
What symptoms may result from other signals interfering with a PACTOR or VARA transmission?
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Frequent retries or timeouts (2% chose this)
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Long pauses in message transmission (0% chose this)
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Failure to establish a connection between stations (12% chose this)
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All these choices are correct (87% chose this)
In what configuration are the individual cells in a solar panel connected together?
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Series-parallel (85% chose this)
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Shunt (5% chose this)
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Bypass (2% chose this)
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Full-wave bridge (9% chose this)
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