Page 1 of 113
NWSA Antenna & Line (A&L) Specialty Comprehensive
Certification EXAM COMPLETE QUESTIONS AND
DETAILED SOLUTIONS LATEST UPDATE THIS YEAR-JUST
RELEASED
SUMMARIZED EXAM COVERAGE (POINT FORM)
• Antenna theory (impedance, radiation patterns, gain, bandwidth, polarization)
• Transmission lines (characteristic impedance, VSWR, return loss, velocity factor, power
handling)
• Line types and connectors (coaxial, open-wire, waveguide, N, 7/16, BNC, TNC, SMA)
• Matching techniques (stubs, transformers, baluns, stub tuners, series/parallel matching)
• Practical installation (tower safety, grounding, lightning protection, corrosion prevention)
• Testing and measurement (VSWR meter, spectrum analyzer, TDR, network analyzer, dummy
loads)
• Environmental effects (ice, wind, temperature, moisture, salt spray, solar radiation)
• Troubleshooting (common faults, intermittent failures, degradation modes)
• RF safety (exposure limits, minimum safe distances, warning signs)
• Standards and best practices (NWSA, ANSI/TIA, IPC, NEC)
1. A crew is installing a new collinear array on a 150-foot tower. What is the primary radiation
characteristic of this antenna type?
A) Figure-eight pattern
B) Omnidirectional in azimuth
C) Unidirectional with high front-to-back ratio
D) Circular polarization
Answer: B
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Rationale: A collinear array consists of multiple dipoles stacked vertically, producing a flattened,
omnidirectional pattern.
2. During a site survey, you measure 2:1 VSWR at the transmitter but 1.2:1 at the antenna feedpoint.
What is the most likely cause?
A) Antenna is detuned
B) High loss in the transmission line
C) Transmitter output stage failure
D) Connector corrosion at the antenna
Answer: B
Rationale: Lossy line reduces reflected power reaching the transmitter, making VSWR appear lower at
the antenna than at the transmitter.
3. An antenna is rated for 5 kW average power but only 2 kW PEP SSB. Why can’t it handle 5 kW PEP
SSB?
A) Average heating is higher on SSB
B) Peak voltages can exceed insulation ratings
C) SSB has 100% duty cycle
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D) The balun will saturate
Answer: B
Rationale: SSB peaks can be 4× average power; high peak voltages may arc across insulators or
connectors.
4. You are replacing a broken fiberglass whip on a vehicle. What must be checked before transmitting?
A) SWR at ½ frequency
B) DC grounding to vehicle chassis
C) Torque on mounting bolts
D) Antenna color for UV resistance
Answer: B
Rationale: Many whips are DC-grounded for lightning protection; failure to ground can cause RF burns or
static buildup.
5. A technician measures the impedance of a folded dipole and finds 300 Ω at resonance. What is the
expected feedpoint impedance for a standard half-wave dipole in free space?
A) 50 Ω
B) 73 Ω
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C) 100 Ω
D) 300 Ω
Answer: B
Rationale: A half-wave dipole is approximately 73 Ω; a folded dipole transforms this to ~300 Ω via
transformer action.
6. After a storm, a yagi’s forward gain drops significantly but VSWR remains good. What is the likely
issue?
A) Corroded connector at the shack
B) A parasitic element has shifted position
C) Water in the coaxial cable
D) Transistor failure in the transmitter
Answer: B
Rationale: Misaligned reflector or director ruins pattern and gain, while feedpoint match may stay
acceptable.
7. A 100-foot run of LMR-400 at 150 MHz has 1.5 dB loss. Approximately what percentage of power
reaches the antenna?
NWSA Antenna & Line (A&L) Specialty Comprehensive
Certification EXAM COMPLETE QUESTIONS AND
DETAILED SOLUTIONS LATEST UPDATE THIS YEAR-JUST
RELEASED
SUMMARIZED EXAM COVERAGE (POINT FORM)
• Antenna theory (impedance, radiation patterns, gain, bandwidth, polarization)
• Transmission lines (characteristic impedance, VSWR, return loss, velocity factor, power
handling)
• Line types and connectors (coaxial, open-wire, waveguide, N, 7/16, BNC, TNC, SMA)
• Matching techniques (stubs, transformers, baluns, stub tuners, series/parallel matching)
• Practical installation (tower safety, grounding, lightning protection, corrosion prevention)
• Testing and measurement (VSWR meter, spectrum analyzer, TDR, network analyzer, dummy
loads)
• Environmental effects (ice, wind, temperature, moisture, salt spray, solar radiation)
• Troubleshooting (common faults, intermittent failures, degradation modes)
• RF safety (exposure limits, minimum safe distances, warning signs)
• Standards and best practices (NWSA, ANSI/TIA, IPC, NEC)
1. A crew is installing a new collinear array on a 150-foot tower. What is the primary radiation
characteristic of this antenna type?
A) Figure-eight pattern
B) Omnidirectional in azimuth
C) Unidirectional with high front-to-back ratio
D) Circular polarization
Answer: B
, Page 2 of 113
Rationale: A collinear array consists of multiple dipoles stacked vertically, producing a flattened,
omnidirectional pattern.
2. During a site survey, you measure 2:1 VSWR at the transmitter but 1.2:1 at the antenna feedpoint.
What is the most likely cause?
A) Antenna is detuned
B) High loss in the transmission line
C) Transmitter output stage failure
D) Connector corrosion at the antenna
Answer: B
Rationale: Lossy line reduces reflected power reaching the transmitter, making VSWR appear lower at
the antenna than at the transmitter.
3. An antenna is rated for 5 kW average power but only 2 kW PEP SSB. Why can’t it handle 5 kW PEP
SSB?
A) Average heating is higher on SSB
B) Peak voltages can exceed insulation ratings
C) SSB has 100% duty cycle
, Page 3 of 113
D) The balun will saturate
Answer: B
Rationale: SSB peaks can be 4× average power; high peak voltages may arc across insulators or
connectors.
4. You are replacing a broken fiberglass whip on a vehicle. What must be checked before transmitting?
A) SWR at ½ frequency
B) DC grounding to vehicle chassis
C) Torque on mounting bolts
D) Antenna color for UV resistance
Answer: B
Rationale: Many whips are DC-grounded for lightning protection; failure to ground can cause RF burns or
static buildup.
5. A technician measures the impedance of a folded dipole and finds 300 Ω at resonance. What is the
expected feedpoint impedance for a standard half-wave dipole in free space?
A) 50 Ω
B) 73 Ω
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C) 100 Ω
D) 300 Ω
Answer: B
Rationale: A half-wave dipole is approximately 73 Ω; a folded dipole transforms this to ~300 Ω via
transformer action.
6. After a storm, a yagi’s forward gain drops significantly but VSWR remains good. What is the likely
issue?
A) Corroded connector at the shack
B) A parasitic element has shifted position
C) Water in the coaxial cable
D) Transistor failure in the transmitter
Answer: B
Rationale: Misaligned reflector or director ruins pattern and gain, while feedpoint match may stay
acceptable.
7. A 100-foot run of LMR-400 at 150 MHz has 1.5 dB loss. Approximately what percentage of power
reaches the antenna?
