Skip to main content

๐“๐ฒ๐ฉ๐ž๐ฌ ๐จ๐Ÿ ๐‘๐š๐๐ข๐จ ๐–๐š๐ฏ๐ž๐ฌ


Types of Radio Waves

๐Ÿ›ฉ๏ธRadio waves of different frequencies have unique characteristics as they propagate through the atmosphere. VLF, LF, & MF waves have relatively long wavelengths and utilize correspondingly long antennas.

๐Ÿ›ฉ๏ธRadio waves produced at these frequencies ranging from 3kHz to 3mHz are known as ground waves or surface waves. They follow the curvature of the earth as they travel from the broadcast antenna to the receiving antenna. Ground waves are particularly useful for long distance transmissions. Automatic direction finders (ADF) & LORAN navigational aids use these frequencies.

โœˆ๏ธHigh frequency (HF) radio waves travel in a straight line & do not curve to follow the earthโ€™s surface. This would limit transmissions from the broadcast antenna to receiving antennas only in the line-of-sight of the broadcast antenna except for a unique characteristic. HF radio waves bounce off of the ionosphere layer of the atmosphere. This refraction extends the range of HF signals beyond line-of-sight. As a result, transoceanic aircraft often use HF radios for voice communication. The frequency range is between 2 to 25 MHz. These kinds of radio waves are known as sky waves.

โœˆ๏ธAbove HF transmissions, radio waves are known as space waves. They are only capable of line-of-sight transmission & do not refract off of the ionosphere. Most aviation communication & navigational aids operate with space waves. This includes VHF (30-300MHz), UHF (300MHz-3GHz), & super high frequency (SHF) (3Ghz-30Ghz) radio waves.

โœˆ๏ธVHF communication radios are the primary communication radios used in aviation. They operate in the frequency range from 118.0 MHz to 136.975MHz. 700 & 20 separate and distinct channels have been designated in this range with 25 kilohertz spacing between each channel. Further division of the bandwidth is possible, such as in Europe where 8.33 kilohertz separate each VHF communication channel. VHF radios are used for communications between aircraft & ATC as well as air-to-air communication between aircraft. When using VHF, each party transmits & receives on the same channel. Only one party can transmit at any one time

โžก๏ธSubscribe us for more aircraft knowledge and aircraft factโฌ…๏ธ
โžก๏ธDo Share with your Friendsโฌ…๏ธ

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

๐“๐ฒ๐ฉ๐ž๐ฌ ๐จ๐Ÿ ๐‚๐จ๐ฆ๐›๐ฎ๐ฌ๐ญ๐ข๐จ๐ง ๐‚๐ก๐š๐ฆ๐›๐ž๐ซ๐ฌ

๐Ÿ›ฉ๏ธA combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, combustion chamber or flame holder. In a gas turbine engine, combustion chamber is fed high pressure air by the compression system. ๐Ÿ›ฉ๏ธThe combustor then heats this air at constant pressure. After heating, air passes from the combustor through the nozzle guide vanes to the turbine. In the case of a ramjet or scramjet engines, the air is directly fed to the nozzle. ๐€๐ง๐ง๐ฎ๐ฅ๐š๐ซ ๐“๐ฒ๐ฉ๐ž โœˆ๏ธThe most commonly used type of combustor is the fully annular combustor. Annular combustors do away with the separate combustion zones and simply have a continuous liner and casing in a ring. There are many advantages to annular combustors, including more uniform combustion, shorter size, lighter, and less surface area. Annular combustors tend to have very uniform exit temperatures. They also have the lowest pressure drop of the three...
Post a Comment
Read more

๐–๐ž๐ญ-๐’๐ฎ๐ฆ๐ฉ ๐Ž๐ข๐ฅ ๐’๐ฒ๐ฌ๐ญ๐ž๐ฆ

Wet Sump Oil System โœณ๏ธThe engine oil system performs several important functions: ๐Ÿ›ฉ๏ธLubrication of the engineโ€™s moving parts . ๐Ÿ›ฉ๏ธCooling of the engine by reducing friction . ๐Ÿ›ฉ๏ธRemoving heat from the cylinders . ๐Ÿ›ฉ๏ธCarrying away contaminants . ๐Ÿ›ฉ๏ธProviding a seal between the cylinder walls and pistons. โžก๏ธSubscribe us for more aircraft knowledge and aircraft factโฌ…๏ธ โžก๏ธDo Share with your Friendsโฌ…๏ธ
Post a Comment
Read more

๐— ๐—ผ๐—ป๐—ผ๐—ฐ๐—ผ๐—พ๐˜‚๐—ฒ ๐˜ƒ๐˜€ ๐—ฆ๐—ฒ๐—บ๐—ถ-๐—บ๐—ผ๐—ป๐—ผ๐—ฐ๐—ผ๐—พ๐˜‚๐—ฒ ๐—ฆ๐˜๐—ฟ๐˜‚๐—ฐ๐˜๐˜‚๐—ฟ๐—ฒ

๐Ÿ›ซA monocoque structure uses its outer shell to support stresses and loads applied to it, whereas a semi-monocoque structure has an internal "skeleton" of supports and braces to keep its shape rigid and strong. ๐Ÿ›ซThe vast majority of pressurized aircraft are semimonocoque to help distribute stresses equally along the fuselage during flight. ๐Ÿ›ซHowever, some helicopters use monocoque structure to maximize internal space in the flight compartment. ๐Ÿ›ซMonocoque fuselage has its skin holding the skeleton structure together while the semi-monocoque has both the skin and the skeleton holding together. ๐Ÿ›ซSemi-monocoque also has "stringers" running horizontally down the plane to help hold the frame together. ๐Ÿ›ซThe monocoque fuselage also cannot be used for airframes after a certain size (small aircraft with single engine), but the semi-monocoque has been used from single piston engines to commercial airliners. ๐Ÿ›ซA monocoque design would also have ...
Post a Comment
Read more