Abbreviations

Abbreviations

Names often used on UHF LRS pages and when talking about radio control and video links and FPV.

RC - Radio Control, remote wireless control of something
RC unit - The radio control unit you hold in your hand, can be a Futaba, JR, Graupner, Multiplex and so on
Servo - when connected to rudders/ailerons/elevator they steer a plane.
Servo pulse - is a digital pulse width that hold position information, 1.5mS is centre position.
LRS - Long Range System, often a short for my system, sometimes also called UHF LRS
UHF - Ultra Height Frequencies, is 300-3000MHz, but radio amateurs often call UHF = 70CM band, also known as the 430-470MHz area
TX - Transmitter used to transfer a signal to a receiver
RX - Receiver used to receive the radio signal and output the signals, pulses, audio, video, data
RC RX - Radio control receiver, can be any type any brand and any coding system, they all output standard servo pulses
LRS TX - the metal box containing the 500mW transmitter used for my long range system.
LRS RX - the receiver located in the plane, this receiver is connected directly to servos and 5V supply
RSSI - received signal strength indication, is often an analogue voltage that goes up or down depending of radio signal level in a receiver
Video TX - Video transmitter, located on a plane, car, boat, helicopter or whatever, often using 900-1300-2400MHz
Video RX - Video receiver, located on ground, when connected to a TV screen you can see live pictures from the Video TX
Video Splitter - is an amplifier that will allow the user to distribute a video signal to several things at the same time.
PPM - Pulse Period Modulation, is the pulse system used in trainer/student systems, it contain high resolution information’s on all servo positions assigned.
PPM inverted - the pulse can be normal or inverted, some older systems do not handle both when connected as student/trainer
LOS - Line Of Sight, is the distance from ground to a plane with nothing in the way, not even ground.
Long Range - is normally not defined, but when a plane is not visible by direct sight it is normally called long range
BNC - is the connector name/type used for the TX and Booster for my LRS, same connector is used on Ethernet systems.
Booster - is an amplifier that will take radio signals and boost them up to a more powerful level.
LNA - Low Noise Amplifier is used in receivers as the front end stage, they improve the sensitivity and therefore also the range
Diversity - is often a double antenna and/or double receiver system with auto switching to the best signal, this improves the useable range allot
GPS - often we use a GPS receiver on planes to feed speed, position, and height information to OSD systems.
OSD - On Screen Display, will overlay interesting information to a live video signal.
Logger - will record data or measurements for playback / view later, some OSD systems can log some information’s too.
Modem - Modulator Demodulator, encode data into sound, and back again, can use audio line in a wireless video system to transfer data like GPS positions
Head Tracker - a unit mounted on a person’s head, will then control remote located servos so a remote camera follow head movements, gives Virtual Reality experience to FPV.
FPV - First Person View, like pilot view out the front window.
UAV - Unmanned Aerial Vehicle, a UAV is a fully computer guided plane, not a radio controlled plane, if RC'ed it is an FPV or just a normal RC plane
Trainer - Most advanced RC units have trainer connectors with PPM in/out so they can be connected via a cable to a student RC unit.
Student - Most advanced RC units have trainer connectors that can be configured to output PPM signals for a PC simulator or trainer RC unit or LRS.
Patch - A patch antenna is a directional antenna that will when pointed to a plane improve the range
Yagi - A Yagi antenna is a directional antenna that will when pointed to a plane improve the range
Dish - A Dish antenna is a directional antenna with highest possible gain, will when pointed to a plane improve the range
Gain - antenna gain is often named in db, more db more gain, and also a more narrow beam, so pointing correctly is harder with high gain.
RF - Radio Frequency, any frequency that is not directly hear able audio
RF module - often a plug in box or module or printed circuit board that can be changed/added in RC units, normally a transmitter
BEC - Battery Eliminator Circuit, is a 5V-6V regulator often linear type that makes supply for RC RX and servos
SBEC - Switching Battery Eliminator Circuit, is a 5V-6V regulator switch mode type handles more input voltage and have lower loss
RC Receiver Battery or Supply, is normally 4 or 5 NIMH cells providing 4.8 or 6V of steady and stable supply, such a battery must be able to handle
 all servo max currents and still provide sufficient stable voltage, do not use spring loaded battery cassettes or weak current capable cells like normal alkaline types,
 Today more new and fancy battery types like lipo and lion and such can also be used if receiver and servos can handle the different voltage range they provide.
Fading - when the distance and positions and angles of a wireless system is changed the radio signal will also change
Multipath Fading - A direct signal and a reflected signal hit receiver antenna with -180 deg phase, creating a zero signal level
Nulling - is the same as Multipath fading
FHSS - Frequency Hopping Spread Spectrum, a way to send data using many different frequencies, makes a system immune to noise and jamming proof.