COMMUNICATION SYSTEMS
The bel most often expresses what value of any component, circuit, or system?
1. Power, 2. Input, 3. Output, 4. Ratio of input to output power
4. Ratio of input to output power
The gain of a transmitting antenna is 9 dB, what will the gain be for the same antenna used for receiving?
1. 9 dB, 2. 6 dB, 3. 4 dB, 4. 3 dB
1. 9 dB
What two windings are used in a latch-in relay?
1. Trip coil and the set coil, 2. Set coil and the reset coil, 3. Reset coil and the trip coil, 4. Latch coil and the unlatch coil
2. Set coil and the reset coil
If you had to post a tag in a wet environment, how could you hang the tag to prevent it from getting damaged?
1. You can't hang tags in wet environments, 2. Duct tape, 3. Clear plastic envelope, 4. Don't hang the tag at all
3. Clear plastic envelope
Heat is removed from the air passing by the heat producing source in an air-to-air cooling system by forcing it through what component?
1. Blower, 2. RF filter, 3. Heat exchanger, 4. Fins
3. Heat exchanger
Which of the following signal levels indicates that the output signal is greater than the input signal?
1 . 5 dB, 2 . +3 dB, 3 . Either 1 or 2 above, 4 . -2 dB
3 . Either 1 or 2 above
All antennas regardless of their shape or size have how many basic characteristics?
1. 1, 2. 2, 3. 3, 4. 4
4. 4
Which, if any, of the following switchboards has greatly reduced hazards to operators and repairmen?
1. Live front, 2. Semi-dead front, 3. Dead front, 4. None of the above
3. Dead front
What does the term "Smart Ship" mean?
1. Don't talk about OPSEC, 2. Acronym to describe safety, 3. Components or systems that are controlled by computer based equipment, 4. Any piece of equipment that contains a PROM
3. Components or systems that are controlled by computer based equipment
Transformer secondary lead markings are identified by which of the following letters?
1. R, 2. H, 3. X, 4. S
3. X
When the asynchronous transmission method is used, each character sent has which of the following control bits?
1. Start bit(s) only, 2. Stop bit(s) only, 3. Both start and stop bits, 4. Parity bits
3. Both start and stop bits
What is the most limiting characteristic of the Yagi antenna?
1. Power-handling, 2. Narrow bandwidth, 3. Physical size, 4. Lack of directivity
2. Narrow bandwidth
When it is desired for the shaft of the synchro receiver to turn clockwise for an increasing reading, the leads should be connected in which of the following ways?
1. S1 transmitter lead to S3 receiver lead, 2. S2 transmitter lead to S1 receiver, 3. Both 1 and 2 above, 4. R1 transmitter lead to R2 receiver lead
3. Both 1 and 2 above
What form must be used to recommend changes to maintenance requirement cards?
1. OPNAV 4790/2K, 2. OPNAV 4790/2R, 3. OPNAV 4790/CK, 4. OPNAV 4790/7B
4. OPNAV 4790/7B
Which of the following devices is used to regulate flow in a seawater cooling system?
1. The gate valve, 2. The globe valve, 3. The orifice plate, 4. The relief valve
2. The globe valve
Tactical radio sets usually operate within which frequency range?
A. 30MHZ – 512MHZ, B. 3MHZ – 30MHZ, C. 1.6MHZ – 30MHZ, D. 1.6MHZ – 512MHZ
D. 1.6MHZ – 512MHZ
A measurement of the voltage to current ratio (Ein/Iout) at the input end of a transmission line is called the
1. input–gain rate, 2. voltage–gain ratio, 3. output impedance, 4. input impedance
4. input impedance
Which of the following data is NOT included in the GPS NAV–msg?
1. Clock–bias, 2. Correction data, 3. Ephemeris, 4. Spectral
4. Spectral
What must be present if there is an electrical jumper in place in which it is not controlled by formal methods?
1. Troubleshooting records, 2. Wire removal forms, 3. Written procedures, 4. A tag
4. A tag
What is the key component of the phase-sequence indicator?
1. The three-phase induction motor, 2. The saturable reactor, 3. The ion drive clutch assembly, 4. The digital display
1. The three-phase induction motor
Which of the following antennas have the widest frequency range?
A. AT-1011, B. RF-3193, C. AV-2011, D. AV-2055-3
B. RF-3193
For an electric field to exist at the surface of a conductor, the field must have what angular relationship to the conductor?
1. 0°, 2. 30°, 3. 45°, 4. 90°
4. 90°
The OMTI field change of the AN/SPS-40B/C/D radar accomplished which of the following results?
1. Replaced the duplexer with a solid state unit, 2. Allowed interface with the AN/SYS-1, 3. Changed the nomenclature of the radar to AN/SPS-40E, 4. Eliminated unit 23
2. Allowed interface with the AN/SYS-1
Who must review tags where the RA uses a tag-out process that is not consistent with the TUMS?
1. Authorizing Officer, 2. Naval Supervisory Authority (NSA), 3. Lead Maintenance Activity (LMA) 4. Both 2 and 3
4. Both 2 and 3
The device that is inserted in the heat exchanger’s water box to concentrate electrolytic action to it vice to the metal of the heat exchanger’s tubes is made of what material (s)?
1. Zinc cathode, 2. Zincs only, 3. Zinc anode only, 4. Both 2 and 3 above
4. Both 2 and 3 above