113: Technical Fundamentals Flashcards
(26 cards)
113.1
Define each band of the electromagnetic spectrum and describe what signals are commonly associated with each
SHF,
SHF: Super High Frequency- 3GHZ to 30GHZ
UHF: Ultra High Frequency- 300MHZ to 3 GHZ
HF: High Frequency- 3MHZ to 30MHZ
VLF: Very Low Frequency- 3 KHZ to 30KHZ
113.2b
Describe the communication capabilities in SHF
Wideband; high bandwidth data SATCOM, IP Services (DoDWB)
113.2c
Describe the communication capabilities in UHF
Narrowband; LOS and SATCOM voice and data services
113.2e
Describe the communication capabilities in HF
around since WW1; long distance transmission of HF signals dependent on refraction
113.2h
Describe the communication capabilities in VLF
sub comms
113.3a
Define and discuss Frequency
measured in Hz; cycles per second
113.3b
Define and discuss Wavelength
distance in space occupied by one radio wave cycle of a at any given instant
113.3c
Define and discuss Ducting
Trapping of an RF wave between two layers of the earth’s atmosphere or between an atmospheric layer and the earth
113.3d
Define and discuss Refraction
change in the direction of the wave when it passes through a different medium
113.3e
Define and discuss Multiplexing
simultaneous transmission of two or more signals over a common carrier wave
113.3f
Define and discuss Bandwidth
difference between the upper frequency limit and the lower frequency limit
113.3g
Define and discuss Keying
Initiates the process of transmitting
113.3h
Define and discuss Azimuth and Elevation Angle
Azimuth Angle: 360 degree angle at which the radio wave travels
Elevation Angle: angle at which the radio wave travels from the antenna to the atmosphere
113.4a
Discuss/describe the Troposphere and how it affects communications
high moisture concentrations; either a signal is attenuated and passed or ducting occurs
113.4c
Discuss/describe the Ionosphere and how it affects communications
interaction of highly charged particles allows more successful long distance communications
113.5c
Discuss propagation paths and give a description of what it means in relation to the atmosphere
path a signal takes from the transmitter to the receiver including any changes caused by passing through the atmosphere
113.6c
Describe the CW modulation type and its usage
continuous wave; electromagnetic wave of constand amplitude and frequency
113.6d
Describe the AM modulation type and its usage
amplitude modulation; modulating an electromagnetic carrier frequency by varying its amplitude IAW the message intelligence that is to be transmitted
113.6e
Describe the FM modulation type and its usage
frequency modulation; conveys information on a carrier wave by varying its frequency
113.7a
Define PRI/PRT as it applies to RADAR
Pulse Repetition Interval/Time - time or duration between the start of one pulse and the start of the next pulse
*reciprocal of PRF
113.7b
Define PRF as it applies to RADAR
Pulse Repetition Frequency - number of pulses transmitted by a radar each second
*reciprocal of PRI/PRT
113.7g
Define scan as it applies to RADAR
time it takes an rf beam to complete one search cycle of the scan pattern
113.8b
Define full Duplex
cell phone; telecommunications between stations happen simultaneously in both directions using two separate frequencies
113.8d
Define simplex
walkie talkie; uses a single channel or frequency to exchange information between 2 or more terminals; one direction only
