Topic G4A Quick Review Audio


What is the purpose of the "notch filter" found on many HF transceivers?

  1. To restrict the transmitter voice bandwidth
  2. To reduce interference from carriers in the receiver passband
  3. To eliminate receiver interference from impulse noise sources
  4. To enhance the reception of a specific frequency on a crowded band


What is one advantage of selecting the opposite, or "reverse," sideband when receiving CW signals on a typical HF transceiver?

  1. Interference from impulse noise will be eliminated
  2. More stations can be accommodated within a given signal passband
  3. It may be possible to reduce or eliminate interference from other signals
  4. Accidental out-of-band operation can be prevented


What is normally meant by operating a transceiver in "split" mode?

  1. The radio is operating at half power
  2. The transceiver is operating from an external power source
  3. The transceiver is set to different transmit and receive frequencies
  4. The transmitter is emitting an SSB signal, as opposed to DSB operation


What reading on the plate current meter of a vacuum tube RF power amplifier indicates correct adjustment of the plate tuning control?

  1. A pronounced peak
  2. A pronounced dip
  3. No change will be observed
  4. A slow, rhythmic oscillation


What is a reason to use Automatic Level Control (ALC) with an RF power amplifier?

  1. To balance the transmitter audio frequency response
  2. To reduce harmonic radiation
  3. To reduce distortion due to excessive drive
  4. To increase overall efficiency


What type of device is often used to match transmitter output impedance to an impedance not equal to 50 ohms?

  1. Balanced modulator
  2. SWR bridge
  3. Antenna coupler or antenna tuner
  4. Q multiplier


What condition can lead to permanent damage to a solid-state RF power amplifier?

  1. Insufficient drive power
  2. Low input SWR
  3. Shorting the input signal to ground
  4. Excessive drive power


What is the correct adjustment for the load or coupling control of a vacuum tube RF power amplifier?

  1. Minimum SWR on the antenna
  2. Minimum plate current without exceeding maximum allowable grid current
  3. Highest plate voltage while minimizing grid current
  4. Maximum power output without exceeding maximum allowable plate current


Why is a time delay sometimes included in a transmitter keying circuit?

  1. To prevent stations from interfering with one another
  2. To allow the transmitter power regulators to charge properly
  3. To allow time for transmit-receive changeover operations to complete properly before RF output is allowed
  4. To allow time for a warning signal to be sent to other stations


What is the purpose of an electronic keyer?

  1. Automatic transmit/receive switching
  2. Automatic generation of strings of dots and dashes for CW operation
  3. VOX operation
  4. Computer interface for PSK and RTTY operation


Which of the following is a use for the IF shift control on a receiver?

  1. To avoid interference from stations very close to the receive frequency
  2. To change frequency rapidly
  3. To permit listening on a different frequency from that on which you are transmitting
  4. To tune in stations that are slightly off frequency without changing your transmit frequency


Which of the following is a common use for the dual-VFO feature on a transceiver?

  1. To allow transmitting on two frequencies at once
  2. To permit full duplex operation - that is, transmitting and receiving at the same time
  3. To permit monitoring of two different frequencies
  4. To facilitate computer interface


What is one reason to use the attenuator function that is present on many HF transceivers?

  1. To reduce signal overload due to strong incoming signals
  2. To reduce the transmitter power when driving a linear amplifier
  3. To reduce power consumption when operating from batteries
  4. To slow down received CW signals for better copy


What is likely to happen if a transceiver's ALC system is not set properly when transmitting AFSK signals with the radio using single sideband mode?

  1. ALC will invert the modulation of the AFSK mode
  2. Improper action of ALC distorts the signal and can cause spurious emissions
  3. When using digital modes, too much ALC activity can cause the transmitter to overheat
  4. All these choices are correct


Which of the following can be a symptom of transmitted RF being picked up by an audio cable carrying AFSK data signals between a computer and a transceiver?

  1. The VOX circuit does not un-key the transmitter
  2. The transmitter signal is distorted
  3. Frequent connection timeouts
  4. All these choices are correct


How does a noise blanker work?

  1. By temporarily increasing received bandwidth
  2. By redirecting noise pulses into a filter capacitor
  3. By reducing receiver gain during a noise pulse
  4. By clipping noise peaks


What happens as the noise reduction control level in a receiver is increased?

  1. Received signals may become distorted
  2. Received frequency may become unstable
  3. CW signals may become severely attenuated
  4. Received frequency may shift several kHz