Extra Exam - E9E
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- D
- E9E08 Which of the following measurements describes a mismatched transmission line? / A. An SWR less than 1:1 / B. A reflection coefficient greater than 1 / C. A dielectric constant greater than 1 / D. An SWR greater than 1:1
- A
- E9E05 How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system? / A. The driven element reactance must be capacitive / B. The driven element reactance must be inductive / C. The driven element resonance must be lower than the operating frequency / D. The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
- B
- E9E07 What parameter best describes the interactions at the load end of a mismatched transmission line? / A. Characteristic impedance / B. Reflection coefficient / C. Velocity factor / D. Dielectric Constant
- B
- E9E04 What is the purpose of the series capacitor in a gamma-type antenna matching network? / A. To provide DC isolation between the feed-line and the antenna / B. To compensate for the inductive reactance of the matching network / C. To provide a rejection notch to prevent the radiation of harmonics / D. To transform the antenna impedance to a higher value
- D
- E9E03 What is the name of the matching system that uses a short perpendicular section of transmission line connected to the feed line near the antenna? / A. The gamma match / B. The delta match / C. The omega match / D. The stub match
- B
- E9E01 What system matches a high-impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center? / A. The gamma matching system / B. The delta matching system / C. The omega matching system / D. The stub matching system
- C
- E9E13 What is the purpose of a "Wilkinson divider"? / A. It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band / B. It is used to feed high-impedance antennas from a low-impedance source / C. It divides power equally among multiple loads while preventing changes in one load from disturbing power flow to the others / D. It is used to feed low-impedance loads from a high-impedance source
- C
- E9E06 What is the equivalent lumped-constant network for a hairpin matching system on a 3-element Yagi? / A. Pi network / B. Pi-L network / C. L network / D. Parallel-resonant tank
- C
- E9E09 Which of these matching systems is an effective method of connecting a 50-ohm coaxial cable feed-line to a grounded tower so it can be used as a vertical antenna? / A. Double-bazooka match / B. Hairpin match / C. Gamma match / D. All of these answers are correct
- C
- E9E10 Which of these choices is an effective way to match an antenna with a 100-ohm terminal impedance to a 50-ohm coaxial cable feed-line? / A. Connect a 1/4-wavelength open stub of 300-ohm twin-lead in parallel with the coaxial feed-line where it connects to the antenna / B. Insert a 1/2 wavelength piece of 300-ohm twin-lead in series between the antenna terminals and the 50-ohm feed cable / C. Insert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable / D. Connect 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
- A
- E9E12 What is the primary purpose of a "phasing line" when used with an antenna having multiple driven elements? / A. It ensures that each driven element operates in concert with the others to create the desired antenna pattern / B. It prevents reflected power from traveling back down the feed-line and causing harmonic radiation from the transmitter / C. It allows single-band antennas to operate on other bands / D. It makes sure the antenna has a low-angle radiation pattern
- B
- E9E11 What is an effective way of matching a feed-line to a VHF or UHF antenna when the impedances of both the antenna and feed-line are unknown? / A. Use a 50-ohm 1:1 balun between the antenna and feed-line / B. Use the "universal stub" matching technique / C. Connect a series-resonant LC network across the antenna feed terminals / D. Connect a parallel-resonant LC network across the antenna feed terminals
- A
- E9E02 What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center? / A. The gamma match / B. The delta match / C. The omega match / D. The stub match