1.4-1.6

Front 1

AMP/MIXER

Back 1

Amplifies the incoming RF signal from the antenna & mixes it with the VCO reference frequency

Front 2

IF Amp

Back 2

Intermediate Frequency Amp - Filters out the sum & two originals, leaving only the difference frequency with the intel

Front 3

Descriminator

Back 3

Filters out the Difference, leaving only the intel from the original tuned radio frequency

Front 4

AGC

Back 4

Automatic Gain Control - Provides a stable output IF signal regardless of variations in the RF output - Automatically controls the voltage

Front 5

Squelch

Back 5

Suppresses the operation of the AF power amplifier when a signal is not present

Front 6

RF Modulator

Back 6

Varies the amplitude of the input VCO reference on the source proportional to the input AF on Gate

Front 7

RF Amplifier

Back 7

Amplifies the output of the RF modulator to a sufficient level for transmission

Front 8

Troublshooting Steps

Back 8

- Symptom Recognition
- Symptom Elaboration - the process of obtaining a more detailed description of the trouble system
- Listing of Probable Faulty Functions - used to isolate the problem down to as few units or sections as possible
- Localizing the Faulty Function - determining which of the functional units of a system is actually at fault

Front 9

Polarization

Back 9

The direction of the electronic field with respect to the earth

Front 10

Atmosphere

Back 10

- I - Ionoshpere
- See - Stratosphere
- The - Troposhere
- Earth - Earth

Front 11

Reflection

Back 11

The turning back of a wave from the boundary of a medium

Front 12

Refraction

Back 12

The changing of direction of a wave as it passes from one medium into another, having a different velocity of propogation

Front 13

Diffraction

Back 13

The bending of radio waves as they pass the edge of an object

Front 14

Coupling Device/Coil

Back 14

Connects the transmitter to the feeder. Also provides impedence matching of the transmitter and transmission line

Front 15

Feeder

Back 15

Transmission line which carries energy to the antenna

Front 16

Antenna

Back 16

Radiates energy into space

Front 17

To radiate max energy into space...

Back 17

The electrical length of the antenna must be at least 1/2 wavelength of the frequency to be radiated.

Front 18

2 types of antennas

Back 18

- Hertz Antenna - Half Wave [DIPOLE or DOBLET]
- Operates independantly of ground and therefore may be used at high altitudes above the earth
- Marconi Antenna - Quarter Wave
- Operates with one end grounded and is mounted perpendicular to the earth or to a surface acting as a ground

Front 19

Input End

Back 19

The end of a transition line connected to a source

Front 20

Output End

Back 20

The end of a line connected to an antenna or other load

Front 21

Two-wire Transmission Lines

Back 21

- Shielded Pair - Permits use at higher frequencies up to 900MHz
- Twisted Pair

Front 22

Coaxial Cable

Back 22

most common type of transmission line in Naval Aircraft

Front 23

Waveguide

Back 23

- Metal Tube specifically designed to guide or conduct electromagnetic waves (usually in the microwave range) through its interior
- esentially a coaxial conductor/cable without a center conductor

Front 24

Waveguide shapes

Back 24

> Elliptical
> Rectangular
> Circular

Front 25

Advantages of a Waveguide

Back 25

- Copper loss is minimal due to a large surface area
- Since there is no center conductor, dielectric loss is eliminated in a wave guide
- Radiation loss in a waveguide is insignificant because the fields are contained within the guide itself

Front 26

3 ways to inject or remove energy from a Waveguide

Back 26

- Probe
- Loop
- Slot

Front 27

Probe

Back 27

> A small probe in the middle of the wide dimension of the waveguide
> Acts as a Quarter-wave antenna

Front 28

Loop

Back 28

> A small loop, usually in the end or side of the wave guide
> Transfers energy

Front 29

Slot

Back 29

> Microwave energy is transferred through a small slot cut in the end of a wave guide

Front 30

Transmitter

Back 30

converts electrical signal into a lightwave signal

Front 31

Optical Fiber

Back 31

Provides a path for the signal

Front 32

Receiver

Back 32

Converts a light wave signal into an electrical signal

Front 33

Advantages of Fiber Optics

Back 33

- Easily repaired
- Very high data transmission rates
- Small size and light weight

Front 34

Construction of Fiber Optics

Back 34

- A transparent dielectric cylinder (CORE) is surrounded by a transparent buffer (CLADDING)
- All of which is encased in a Primary Protective Jacket, a Strength Member, and a Protective Outer Jacket

Front 35

Core

Back 35

The center dielectric in an optical fiber

Front 36

Cladding

Back 36

A sheathing or covering, usually of glass or plastic, fused to the core

Front 37

Protective Jackets

Back 37

Due to their fragile nature, single fibers and fiber bundles must have protective covers

Front 38

Step Index

Back 38

- Abrupt Refractive Index
- At proper angles, acts like a mirror
- Used for short distances

Front 39

Graded Index

Back 39

- A variation of Refractive Index
- Causes the light ray to be continuously refocused as it travels down the fiber
- Used for longer distances

Front 40

3 Alignment Errors of Fiber Optics

Back 40

- Gap - The end-to-end separation of the fiber
- Axial - Offset of the fibers in a perpendicular direction
- Angular - Angle between the fibers