What is an effect of excessive phase noise in an SDR receiver's master clock oscillator?

1. A It limits the receiver's ability to receive strong signals
2. B It can affect the receiver's frequency calibration
3. C It decreases the receiver's third-order intercept point
4. D It can combine with strong signals on nearby frequencies to generate interference

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

1. A A front-end filter or preselector
2. B A narrow IF filter
3. C A notch filter
4. D A properly adjusted product detector

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

1. A Desensitization
2. B Cross-modulation interference
3. C Capture effect
4. D Frequency discrimination

What is the noise figure of a receiver?

1. A The ratio of atmospheric noise to phase noise
2. B The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
3. C The ratio in dB of the noise generated in the receiver to atmospheric noise
4. D The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

What does a receiver noise floor of -174 dBm represent?

1. A The receiver noise is 6 dB above the theoretical minimum
2. B The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
3. C The noise figure of a 1 Hz bandwidth receiver
4. D The receiver noise is 3 dB above theoretical minimum

How much does increasing a receiver's bandwidth from 50 Hz to 1,000 Hz increase the receiver's noise floor?

1. A 3 dB
2. B 5 dB
3. C 10 dB
4. D 13 dB

What does the MDS of a receiver represent?

1. A The meter display sensitivity
2. B The minimum discernible signal
3. C The modulation distortion specification
4. D The maximum detectable spectrum

An SDR receiver is overloaded when input signals exceed what level?

1. A One-half of the maximum sample rate
2. B One-half of the maximum sampling buffer size
3. C The maximum count value of the analog-to-digital converter
4. D The reference voltage of the analog-to-digital converter

Which of the following choices is a good reason for selecting a high IF for a superheterodyne HF or VHF communications receiver?

1. A Fewer components in the receiver
2. B Reduced drift
3. C Easier for front-end circuitry to eliminate image responses
4. D Improved receiver noise figure

What is an advantage of having a variety of receiver bandwidths from which to select?

1. A The noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity
2. B Receiver power consumption can be reduced when wider bandwidth is not required
3. C Receive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference
4. D Multiple frequencies can be received simultaneously if desired

Why does input attenuation reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

1. A The attenuator has a low-pass filter to increase the strength of lower frequency signals
2. B The attenuator has a noise filter to suppress interference
3. C Signals are attenuated separately from the noise
4. D Atmospheric noise is generally greater than internally generated noise even after attenuation

How does a narrow-band roofing filter affect receiver performance?

1. A It improves sensitivity by reducing front-end noise
2. B It improves intelligibility by using low Q circuitry to reduce ringing
3. C It improves blocking dynamic range by attenuating strong signals near the receive frequency
4. D All these choices are correct

What is reciprocal mixing?

1. A Two out-of-band signals mixing to generate an in-band spurious signal
2. B In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
3. C Two digital signals combining from alternate time slots
4. D Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals

What is the purpose of the receiver IF Shift control?

1. A To permit listening on a different frequency from the transmitting frequency
2. B To change frequency rapidly
3. C To reduce interference from stations transmitting on adjacent frequencies
4. D To tune in stations slightly off frequency without changing the transmit frequency