NAVEDTRA 14189A Module 17 Chapter 1 Flashcards
What are the two types of electrical communications?
Radio and wire
What is the main advantage of radiotelegraph communications?
Reliability
Why is radiotelephone one of the most useful methods of military communications?
It is direct, convenient and easy to use
What are the disadvantages of radiotelephone communications?
Static, enemy interference or a high local noise level
What is the main use of a radio teletypewriter?
High speed automatic communications across ocean areas
What is facsimile?
The process used to transmit photographs, charts and other graphic information electronically
A system is subdivided into what levels?
Set, group, unit, assembly, subassembly, and part
In the example 1A6CR3, what is the assembly designator?
A6
The majority of vlf transmitters are used for what purpose?
Fleet communications or navigation
Today the Navy uses lf communications as a segment of what operational system?
Fleet Multichannel Broadcast System
Why does the Navy only use the upper and lower ends of the mf band?
Due to the commercial broadcast (AM) band
What are the four general types of communications services in the hf band?
Point-to-point, ship-to-shore, ground-to-air, and fleet broadcast
A message transmitted on several frequencies at the same time is an example of what type of transmission?
Frequency-diversity
Physically separating receive antennas is an example of what technique?
Space-diversity
When using frequencies above 30 megahertz, you are normally limited to using what range?
Line of sight
