HAM FREE Ham Radio Extra Class Questions and Answers 2 — Questions and Answers
Question 1: What is the purpose of a Smith chart in amateur radio?
- To graphically represent complex impedance and solve transmission line problems (Correct answer)
- To calculate antenna gain in dBi
- To map propagation paths across the ionosphere
- To determine the legal power limits for Extra class operators
Correct answer: To graphically represent complex impedance and solve transmission line problems
A Smith chart is a graphical tool used to represent complex impedance and admittance, making it easier to solve transmission line matching problems.
Question 2: Which emission type designator represents a single-sideband suppressed-carrier voice signal?
- F3E
- A1A
- J3E (Correct answer)
- C3F
Correct answer: J3E
J3E is the ITU emission designator for single-sideband suppressed-carrier analog voice transmission.
Question 3: What is the maximum symbol rate permitted for RTTY or data emission on the 20-meter band for Extra class licensees?
- 300 baud (Correct answer)
- 1200 baud
- 19.6 kilobaud
- 56 kilobaud
Correct answer: 300 baud
On the 20-meter band, the maximum symbol rate for RTTY and data emissions is 300 baud per FCC Part 97.
Question 4: What happens to the noise figure of a receiver when a lossy component is placed before the first amplifier stage?
- The noise figure improves proportionally
- The noise figure degrades by approximately the loss of the component (Correct answer)
- The noise figure remains unchanged
- The noise figure is cut in half
Correct answer: The noise figure degrades by approximately the loss of the component
Any loss before the first amplifier stage directly adds to the receiver's noise figure by approximately the same amount in dB.
Question 5: In a phase-locked loop (PLL) circuit, what is the function of the voltage-controlled oscillator (VCO)?
- To filter out harmonics from the reference oscillator
- To divide the output frequency for the phase detector
- To generate an output frequency that varies with the applied control voltage (Correct answer)
- To convert digital signals to analog for modulation
Correct answer: To generate an output frequency that varies with the applied control voltage
The VCO produces an output signal whose frequency changes in proportion to the DC control voltage applied to it.
Question 6: What is the primary advantage of using a Beverage antenna for receiving on the low HF bands?
- Extremely high transmit gain
- Very high directivity and low-angle reception with excellent noise rejection (Correct answer)
- Compact size suitable for portable operation
- Circular polarization for satellite work
Correct answer: Very high directivity and low-angle reception with excellent noise rejection
A Beverage antenna is a long-wire receiving antenna prized for its directivity and ability to reject noise from unwanted directions on low-frequency bands.
HAM FREE Ham Radio Extra Class Questions and Answers 2
What is the purpose of a Smith chart in amateur radio?