1|Page
General Communications Technician Level 2 (GCT2)
Certification Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the General
Communications Technician Level 2 (GCT2) Certification Exam, an advanced,
journeyman-level assessment administered by ETA International. The exam goes beyond
basic electronics to evaluate a candidate’s ability to install, maintain, and troubleshoot
complex communication infrastructure, covering advanced RF propagation and antenna
theory, digital modulation techniques (PCM, PAM), microwave and fiber optic systems
(SONET, DWDM), public safety standards (Project 25, FirstNet), IP-based networking
(VLANs, routing, multicast), regulatory compliance (FCC, ITU), and emerging technologies
such as Distributed Antenna Systems (DAS) and early 5G implementations.
QUESTION 1
What is the primary advantage of using a log-periodic dipole array (LPDA) for wideband
spectrum monitoring?
A) High directivity at a single frequency
B) Constant impedance and gain over a wide frequency range
C) Circular polarization capability
D) Low noise figure at microwave frequencies
CORRECT ANSWER: B
EXPERT RATIONALE: LPDA maintains relatively constant input impedance and gain
across its design bandwidth, making it ideal for broadband applications like spectrum
monitoring.
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QUESTION 2
In a T1 digital transmission system using Alternate Mark Inversion (AMI) line coding,
what condition causes a Bipolar Violation (BPV)?
A) Two consecutive positive pulses
B) Two consecutive negative pulses
C) A pulse with the same polarity as the previous nonzero pulse
D) Absence of pulses for more than 125 microseconds
CORRECT ANSWER: C
EXPERT RATIONALE: AMI alternates polarity for each successive '1' bit; two same-
polarity nonzero pulses in a row constitute a BPV, indicating a line code error.
QUESTION 3
What is the typical bit error rate (BER) threshold used for acceptable voice quality on a
Project 25 (P25) Phase 2 trunked radio system?
A) 1x10^-3
B) 1x10^-5
C) 1x10^-8
D) 1x10^-10
CORRECT ANSWER: A
EXPERT RATIONALE: P25 systems use forward error correction (FEC) to achieve usable
voice quality at a raw BER up to 1x10^-3, beyond which intelligibility degrades
significantly.
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QUESTION 4
Which SONET/SDH overhead byte is responsible for carrying alarm and performance
monitoring information between regenerators?
A) A1/A2 framing bytes
B) J0 trace byte
C) F1 user channel
D) E1/E2 orderwire bytes
CORRECT ANSWER: B
EXPERT RATIONALE: The J0 (section trace) byte, part of the section overhead, allows
regenerators to verify connectivity and monitor performance across the section.
QUESTION 5
When deploying a Distributed Antenna System (DAS) for a large stadium, which
component combines multiple RF sources (e.g., cellular, public safety) onto a single fiber
backbone?
A) Remote antenna unit (RAU)
B) Optical distribution master (ODM)
C) Bidirectional amplifier (BDA)
D) Hybrid combiner
CORRECT ANSWER: B
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EXPERT RATIONALE: The ODM (or head-end unit) accepts donor signals from various
base stations, converts them to optical wavelengths, and multiplexes them onto fiber for
transport to remote units.
QUESTION 6
In IP-based radio dispatch systems, which protocol is commonly used to transport voice
packets between consoles and base stations with low latency?
A) SIP (Session Initiation Protocol)
B) RTP (Real-time Transport Protocol)
C) SNMP (Simple Network Management Protocol)
D) HTTP/2
CORRECT ANSWER: B
EXPERT RATIONALE: RTP provides end-to-end delivery of real-time audio, including
sequence numbering and timestamping, essential for voice dispatch over IP networks.
QUESTION 7
What is the main purpose of a circulator in a microwave transmitter output stage?
A) To increase the peak envelope power (PEP)
B) To isolate the transmitter from reflected power due to antenna mismatch
C) To convert linear polarization to circular polarization
D) To suppress spurious emissions below FCC limits
General Communications Technician Level 2 (GCT2)
Certification Exam | Latest Verified Questions and
Detailed Answers
OVERVIEW DESCRIPTION:
This comprehensive set of multiple-choice questions is designed for the General
Communications Technician Level 2 (GCT2) Certification Exam, an advanced,
journeyman-level assessment administered by ETA International. The exam goes beyond
basic electronics to evaluate a candidate’s ability to install, maintain, and troubleshoot
complex communication infrastructure, covering advanced RF propagation and antenna
theory, digital modulation techniques (PCM, PAM), microwave and fiber optic systems
(SONET, DWDM), public safety standards (Project 25, FirstNet), IP-based networking
(VLANs, routing, multicast), regulatory compliance (FCC, ITU), and emerging technologies
such as Distributed Antenna Systems (DAS) and early 5G implementations.
QUESTION 1
What is the primary advantage of using a log-periodic dipole array (LPDA) for wideband
spectrum monitoring?
A) High directivity at a single frequency
B) Constant impedance and gain over a wide frequency range
C) Circular polarization capability
D) Low noise figure at microwave frequencies
CORRECT ANSWER: B
EXPERT RATIONALE: LPDA maintains relatively constant input impedance and gain
across its design bandwidth, making it ideal for broadband applications like spectrum
monitoring.
,2|Page
QUESTION 2
In a T1 digital transmission system using Alternate Mark Inversion (AMI) line coding,
what condition causes a Bipolar Violation (BPV)?
A) Two consecutive positive pulses
B) Two consecutive negative pulses
C) A pulse with the same polarity as the previous nonzero pulse
D) Absence of pulses for more than 125 microseconds
CORRECT ANSWER: C
EXPERT RATIONALE: AMI alternates polarity for each successive '1' bit; two same-
polarity nonzero pulses in a row constitute a BPV, indicating a line code error.
QUESTION 3
What is the typical bit error rate (BER) threshold used for acceptable voice quality on a
Project 25 (P25) Phase 2 trunked radio system?
A) 1x10^-3
B) 1x10^-5
C) 1x10^-8
D) 1x10^-10
CORRECT ANSWER: A
EXPERT RATIONALE: P25 systems use forward error correction (FEC) to achieve usable
voice quality at a raw BER up to 1x10^-3, beyond which intelligibility degrades
significantly.
,3|Page
QUESTION 4
Which SONET/SDH overhead byte is responsible for carrying alarm and performance
monitoring information between regenerators?
A) A1/A2 framing bytes
B) J0 trace byte
C) F1 user channel
D) E1/E2 orderwire bytes
CORRECT ANSWER: B
EXPERT RATIONALE: The J0 (section trace) byte, part of the section overhead, allows
regenerators to verify connectivity and monitor performance across the section.
QUESTION 5
When deploying a Distributed Antenna System (DAS) for a large stadium, which
component combines multiple RF sources (e.g., cellular, public safety) onto a single fiber
backbone?
A) Remote antenna unit (RAU)
B) Optical distribution master (ODM)
C) Bidirectional amplifier (BDA)
D) Hybrid combiner
CORRECT ANSWER: B
, 4|Page
EXPERT RATIONALE: The ODM (or head-end unit) accepts donor signals from various
base stations, converts them to optical wavelengths, and multiplexes them onto fiber for
transport to remote units.
QUESTION 6
In IP-based radio dispatch systems, which protocol is commonly used to transport voice
packets between consoles and base stations with low latency?
A) SIP (Session Initiation Protocol)
B) RTP (Real-time Transport Protocol)
C) SNMP (Simple Network Management Protocol)
D) HTTP/2
CORRECT ANSWER: B
EXPERT RATIONALE: RTP provides end-to-end delivery of real-time audio, including
sequence numbering and timestamping, essential for voice dispatch over IP networks.
QUESTION 7
What is the main purpose of a circulator in a microwave transmitter output stage?
A) To increase the peak envelope power (PEP)
B) To isolate the transmitter from reflected power due to antenna mismatch
C) To convert linear polarization to circular polarization
D) To suppress spurious emissions below FCC limits
