What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

1. A Removal of the CW signal as well as the interfering carrier
2. B Any nearby signal passing through the DSP system will overwhelm the desired signal
3. C Excessive ringing
4. D All these choices are correct

Which of the following types of noise can often be reduced by a digital noise reduction?

1. A Broadband white noise
2. B Ignition noise
3. C Power line noise
4. D All these choices are correct

Which of the following types of noise are removed by a noise blanker?

1. A Broadband white noise
2. B Impulse noise
3. C Hum and buzz
4. D All these choices are correct

How can conducted noise from an automobile battery charging system be suppressed?

1. A By installing filter capacitors in series with the alternator leads
2. B By installing a noise suppression resistor and a blocking capacitor at the battery
3. C By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the antenna feed line
4. D By installing ferrite chokes on the charging system leads

What is used to suppress radio frequency interference from a line-driven AC motor?

1. A A high-pass filter in series with the motor's power leads
2. B A brute-force AC-line filter in series with the motor's power leads
3. C A bypass capacitor in series with the motor's field winding
4. D A bypass choke in parallel with the motor's field winding

What type of electrical interference can be caused by computer network equipment?

1. A A loud AC hum in the audio output of your station's receiver
2. B A clicking noise at intervals of a few seconds
3. C The appearance of unstable modulated or unmodulated signals at specific frequencies
4. D A whining-type noise that continually pulses off and on

Which of the following can cause shielded cables to radiate or receive interference?

1. A Low inductance ground connections at both ends of the shield
2. B Common-mode currents on the shield and conductors
3. C Use of braided shielding material
4. D Tying all ground connections to a common point resulting in differential-mode currents in the shield

What current flows equally on all conductors of an unshielded multiconductor cable?

1. A Differential-mode current
2. B Common-mode current
3. C Reactive current only
4. D Magnetically-coupled current only

What undesirable effect can occur when using a noise blanker?

1. A Received audio in the speech range might have an echo effect
2. B The audio frequency bandwidth of the received signal might be compressed
3. C Strong signals may be distorted and appear to cause spurious emissions
4. D FM signals can no longer be demodulated

Which of the following can create intermittent loud roaring or buzzing AC line interference?

1. A Arcing contacts in a thermostatically controlled device
2. B A defective doorbell or doorbell transformer inside a nearby residence
3. C A malfunctioning illuminated advertising display
4. D All these choices are correct

What could be the cause of local AM broadcast band signals combining to generate spurious signals on the MF or HF bands?

1. A One or more of the broadcast stations is transmitting an over-modulated signal
2. B Nearby corroded metal connections are mixing and reradiating the broadcast signals
3. C You are receiving skywave signals from a distant station
4. D Your station receiver IF amplifier stage is overloaded

What causes interference received as a series of carriers at regular intervals across a wide frequency range?

1. A Switch-mode power supplies
2. B Radar transmitters
3. C Wireless security camera transmitters
4. D Electric fences

Where should a station AC surge protector be installed?

1. A At the AC service panel
2. B At an AC outlet
3. C On the single point ground panel
4. D On a ground rod outside the station

What is the purpose of a single point ground panel?

1. A Remove AC power in case of a short-circuit
2. B Prevent common-mode transients in multi-wire systems
3. C Eliminate air gaps between protected and non-protected circuits
4. D Ensure all lightning protectors activate at the same time