Always under construction By Hugh Stegman nv6H

QSL (?) (1) I am acknowledging receipt (Did you receive?)

(2) A card or letter confirming reception of a radio station

(3) Acknowledgment of transmission, a fancy "roger"

QSO (?) (1) Contact me [on -- kHz] (Should I contact you?)

(2) Communications between two or more stations (informal)

QST (1) General call: "Hello all amateurs"

(2) Ham radio magazine published by ARRL

QSTAG Qadripartite Standardization Agreement

QSV (?) Send Vs (Should I send Vs?)

QSX (?) I am listening [on -- kHz] (Are you listening [on -- kHz]?)

QSY (?) (1) Change frequency [to -- kHz] Should I change frequency [to -- kHz]?

(2) Any frequency change (informal)

QTC (?) (1) I have [number] messages (Do you have messages?)

Message traffic in standard form (informal)

QTH (?) (1) My station location is… (What is your location?)

Station location in general

QWD Quarterly World Days, observation intervals

QWERTY Name of standard typewriter keyboard, from top row of ltrs

QWR Quarter-Wave Rule

QWZ Facetious prosign: Are you woozy? I am woozy

R (1) CW prosign: "Message received"

(2) DC resistance (in ohms)

(3) Resistor

(4) Right

(5) Runway

R chks Radio checks

R&D Research & Development

R&O Report & Order (FCC)

R/T Receiver/Transmitter

R/W Rotary wing (helicopter)

R3E Single sideband, reduced carrier (usually 6 dB) radiotelephony

RA (1) Radio Authority (UK)

(2) Rain

(3) Radio Australia

(4) Radio Altimiter

(5) File format: Real Audio

RAA Royal Australian Army

RAAF Royal Australian Air Force

RAC-ARQ ARQ mode propietary to Racal/Thales

RACES Radio Amateur Civil Emergency Service, FEMA affiliates

Racon Radar Beacon

RACH Random Access CHannel

RAD Radiological [~]

Radar Radio Detection And Ranging

RADARA Regional And Domestic Air Route Area

RADAY Radio Day (US Mil)

RADIL ROCC/AWACS digital information link

RADINT (1) Radar intelligence

(2) Radiation intelligence

RADIUS Remote Authentication Dial In User Service

RADM Rear Admiral

RADMO Radio Mode

RADSL Rate Adaptive Asymmetric Digital Subscriber Line

RADSTA Radio Station

RAF Royal Air Force

RAG Replacement Air Group

RAI Radio Televisione Italiana

RAID (1) Redundant Array of Inexpensive Disks (servers)

(2) Rapid Assessment and Initial Detection team (FEMA/Army NG)

RAIL Runway Alignment Indicator Lights

RAIM Receiver Autonomous Integrity Monitoring

RAM (1) Random Access Memory (can be changed)

(2) Radar-Absorbing Material

RAMAC Random Access Method Of Accounting And Control (IBM, 1956)

RAMDAC Random Access Memory Digital to Analog Converter

RAMP Radar Modernization Project

RAN (1) Radio Access Number

(2) Royal Australian Navy

RAOC rear area operations center

RAP (1) Radar-Absorbing Paint

(2) RAPid Refresh Model (wx)

RAPCON Radar approach control

RARP Reverse Address Resolution Protocol

RAS Remote Access Server

RASC Radio Atmospheric Science Center (Japan)

RASP Radio Science And Propagation

RATCF Radar Air Traffic Control Facility (USN)

RATS Radio Amateur Telecommunications Society

RATT Radioteletype (usually military 75/100 bd)

RAV Restricted Availability

RAVEC Radar Vector

RB Radar Beacon

RBER Residual Bit-Error Ratio

RBL Realtime Blackhole List (spam filtering)

RB-S Response Boat - Small (USCG)

RBS Radar Bomb Scoring

RBW Resolution BandWidth

RC (1) Reserve Components (US Army)

(2) Radio control

RCA Radio Corporation of America

RCC (1) Rescue Coordination Center (GMDSS)

(2) Range control center (USAF)

(3) Resource control complex

(4) Rag Chewer's Club (ham award)

RCCC Range communications control center

RCDS Raster Chart Display System

RCI Radio Canada International

RCIED Remote Controlled Improvised Explosive Device

RCMA Dead scanner radio club, which included HF utility

RCNC Range communications network controller

RCNY Rules of the City of New York

RCO Range Control Officer

rcp Remote Copy (unix)

RCP Resource Change Proposal

RCR Runway Condition Reading

RCS (1) Radio Communication System

(2) Reaction Control System (NASA)

(3) Radar cross-section

(4) Radio Conference Subcommittee (of IRAC)

(5) Remote Control System

rcv Receive mode

rcvr receiver

RD (1) replacement directorate

(2) Restricted data

(3) Regional Director

(4) Radar man (old USCG grade)

RDARA Regional and Domestic Air Route Area

RDEC Research, Development and Engineering Center (Army)

RDF (1) Radio direction finding

(2) Resource Description Framework

(3) Resource Description Format

(4) Rapid Deployment Force

(5) Repeater Distribution Frame (telephony)

(6) Raw Data File

(7)Record Description Field

RDFT Redundant Digital File Transfer (used by HM01)

RDM (1) Radio Data Modem

(2) Radio Diffusion Marocaine (Morroco)

RDNS Reverse Domain Name System lookup (Internet)

RDRAM RAMBUS (company) Dynamic Random Access Memory

RDS (1) Radio Data System (FM car radios)

(2) Remote Data Service

RDT Remote digital terminal

RE Reverse engineering

REACT Radio Emergency Associated Communication Team, like ARES,

but on CB and GMRS

REC Radio-electronic combat

rec receive

recon reconnaissance

REDHORSE Rapid Engineer Deployable Heavy Operational Repair Squadron, Engineer

REE Radio Exterior de Espana (Spain overseas broadcaster)

Reg regulation, includes radio rules

REJ Packet control frame: Reject, data out of sequence

Rem (1) Remark (computer programming)

(2) Radiation-equivalent, man (nuclear safety)

REMES Reference Message

REP Radiological Emergency Preparedness (program)

REQ request

req'd required

RES Radio Equipment and Systems

RETMA Radio, Electronics, Television Manufacturers Assn, now EIA

retrans retransmission

rev reverse

RF Radio Frequency

RF/EMPINT Radio Frequency/Electromagnetic Pulse Intelligence

RFC (1) RF Choke

(2) Request For Comment (Internet standards)

RFDS Royal Flying Doctor Service (Australia)

RFDU RF distribution unit

RFE Radio Free Europe

RFI (1) RF Interference

(2) Radio France International

RFID Radio Frequency Identification

RFMU Radio Frequency Monitoring Unit

RFP Request For Proposals

RFPI Radio For Peace International, Costa Rica

RFR RF radiation

RG-# Radio Guide, Radio Group, Radio Grade (differs) - coax cable designator

RGB Red, Green, Blue; additive color mixing like TV

RGS Remote ground station

RH Relative Humidity

RHC Radio Havana Cuba

RHCP Right-hand circular polarization

RHOJ Radar home on jam

RI (1) Routing indicator (Telex or radiograms)

(2) Ring Indicator (modem line)

RIAA Recording Industry Assn of America (audio)

RIFF Resource Interchange File Format (Microsoft MIDI)

RIMM (1) RAMBUS In-Line Memory Module

(2) Removable Interchangeable Media Module

RIN Relative-Intensity Noise

RIO (1) Radar Intercept Officer

(2) Relative Ionospheric Opacity

Riometer Relative Ionospheric Opacity Meter (uses cosmic RF)

RIPE Regional Internet Registry for Europe

RIPE Reseaux IP Europeens (Internet registry)

RISC Reduced Instruction Set Computing, chip architecture

RIT Receiver Incremental Tuning, same as "clarifier"

RITL Radio In The Loop (telephony)

RJ Radio Japan

RLC Resistance-Inductance-Capacitance (network)

RLL Radio Local Loop

Rlogin Remote Login, networking program like telnet

RM (1) ("Romeo Mike") Radioman, radio operator

(2) Radio Man (old USCG grade, became TC)

(3) File extension: Real Media

RMA (1) Revolution in Military Affairs (US tax subsidized paper crunching)

(2) Return Merchandise Authorization

(3) Reduced Major Axis)

(4) Old Microsoft midi file format (see MIDI)

RMC Regional Meteorological Center

RMI (1) Radio Magnetic Indicator

(2) Republic of the Marshall Islands

(3) RIFF MIDI (an acronym made up of acronyms)

(4) Radio Miami International

RMK Remarks

RMP (1) Radio Mobile Patrol (NYPD car)

(2) Radio Motor Patrol

(3) Radio Móvil Privada (Spanish: Private Mobile Radio)

(4) Raster Map Product

(5) Radio Merkury Poznan (Poland)

RMS (1) Royal Majesty Ship

(2) Royal Mail Steamer (obsolete?)

(3) Root Mean Square

(4) Remote Mine Sweeping

(5) Radar Manual Systems

(6) Remote Manipulator System (space shuttle's robot arm)

RMTN Region IV Meteorological Telecommunication Network

RN (1) Radio Netherlands

(2) Royal Navy

(3) Registered Nurse

(4) Revision Notice

Radio Netherlands

rn Read News, usually the default Unix Usenet reader

RNAV Area Navigation (IFR flight)

RNDZ Rendezvous

RNP Required Navigation Performance

RNP/AR Required Navigation Performance Authorization Required

RNR Packet control frame: Receive Not Ready

RNZ Radio New Zealand

RNZAF Royal New Zealand Air Force

RNZI Radio New Zealand International

RNZN Royal New Zealand Navy

RO (1) Radio Officer (traditionally trained in Morse code)

(2) Receive Only

ROA Remotely Operated Aircraft

ROC (1) Regional Operating Center (FEMA/NCS)

(2) Rear operations center

(3) Reservoir Operating Center (USACE)

ROCC Regional Operations Control Center

ROE Rules Of Engagement

ROFL Rolling On Floor Laughing (Internet, also ROTFL)

ROFOR Route Forecast

Roger Voice Prosign: Message Received (from "R" in Morse code)

ROLAP relational on-line analytical processing (databases)

ROM Read Only Memory (can't easily be changed)

ROMES Refrence Our Message

ROMPRES Romanian press agency

RON Remain Over Night (US military)

ROSE RATS Open System Environment (Packet; see RATS)

ROTATE Radar Observations of Tornadoes And Thunderstorms Experiment

ROTFL Rolling On The Floor Laughing (Internet, also ROFL)

ROTHR Relocatable (HF) Over-The-Horizon Radar

ROTR Receive-Only Typing Reperforator (tape printer)

ROU-FEC Romanian FEC

ROVER Remote Out-of-Vehicle Emergency Radio (LAPD)

RP (1) Received Pronunciation (British radio "accent")

(2) Reporting Party (Police)

RP-1 Rocket Propellant #1, kerosene rocket fuel

RPA (1) Remote Passphrase Authentication

(2) Radio-Programming Application

RPC Remote Procedure Call (lousy Windoze security)

RPG Report Program Generator (strange IBM computer language)

RPI Runway Point of Intercept

RPM Red (Hat) Package Manager (Linux)

rpm Rotations per minute

RPN Reverse Polish Notation (computing)

rpt (1) Reception report

(2) CW prosign: repeat

Rptr Repeater

RPU Remote Pickup Unit

RQ (1) Repeat Request

(2) Request acknowledgment of receipt (DSC protocol)

RQS Request to send (modem handshaking line, rare name for RTS)

RR (1) Transmission is in Russian

(2) Radio Regulation (ITU)

(3) Railroad (don't laugh, some use HF)

(4) Packet control frame: Receive Ready

(5) Response and Recovery Directorate (FEMA)

(6) Radio Reloj (clock radio, SS news format)

RRC (1) Regional Radio Conference (ITU)

(2) Range Rate Correction (DGPS)

RRP Runway Reference Point

RRSS Radparker Relay Spam Stopper

RRx Routine Report, where x is a sequential letter, used for delayed METAR

RS (01) radiated susceptibility

(02) range squadron

(03) reentry system

(04) requirements submission

(05) resource scheduling

(06) Radio Satellite (Russian amateur)

(07) EIA Recommended Standard, RS-232 was one

(08) Record Separator (ASCII)

(09) Radio Sweden

(10) Reference Station

RS-232 Recommended Standard 232, standard serial I/O, now EI-232

RSA (1) Rivest-Shamir-Adelman, inventors of a proprietary type of

public-key encryption

(2) Republic of South Africa

RSGB Radio Society of Great Britain

rsh Restricted shell (Unix)

RSN Real Soon Now (when everything is going to happen)

RSO Range Safety Officer

RSOC Regional SIGINT Operation Center (like Menwith, UK)

RSR Remote Secure Receiver (GPS)

RSS (1) Really Simple Syndication (world wide web)

(2) Radio Subsystem

(3) RDF Site Summary (see RDF #2)

(4) Rich Site Summary

RSSI Received Signal Strength Indicator

RST (1) Signal report: Readability, Strength, [Tone] (if CW)

(2) Reset

RSTA reconnaissance, surveillance and target acquisition

RSU RoadSide Unit (auto toll collection)

RSVP (1) Resource Reservation Protocol

(2) Repondez Si'Vous Plait (Please Respond, party invitations)

RT (1) Radiotelephone

(2) Receiver-transmitter

(3) Receive Timing

(4) routing table

RTB Return to base

RTC (1) Rail Traffic Control

(2) Remote Type Certification

RTCA Radio Technical Commission for Aeronautics

RTCE Reat-Time Channel Evaluation

RTCM Radio Technical Commission for Maritime (services)

RTCP Real Time Control Protocol

RTD Return to duty

RTDC Real time data controller

RTE Radio Telefs Éireann (Ireland)

RTF (1) Radiodiffusion Television Francais

(2) Runtime file

RTFM Read the [fine] manual

RTFMS Real-Time (HF) Frequency Management Software

RTHK Radio Television Hong Kong

RTLS (1) Return to launch site

(2) Real-Time Locating Systems

RTO (1) Responsible Test Organization (US)

(2) Radiotelephone Operator (LAPD)

(3) Range training officer

RTOK Retest OK

RTOS Real Time Operating System

RTS Request To Send (secondary handshaking modem line)

RTT (1) Radioteletype

(2) Radio Transmission Technology

RTTY Radioteletype

RTZ Return To Zero

R-UIM Removable User Identity Module

RUMES Reference Your Message

RVR Runway Visual Range

RVRNO RVR system not available

RVSM Reduced Vertical Separation Minimum

RWI radio wire integration (changed to NRI-net radio interface)

RWR Radar Warning Receiver

RWY runway

RX (1) Receiver

(2) Religious programming

(3) Retransmission

RXD Received Data (Serial I/O)

RXR Receive Reversed (usually RTTY Mark/Space)

RY RYRYRY teleprinter test call

RZ Return to Zero

RZL Return to Zero Level

S (1) south

(2) Siemen

s second

S&TCD Space and Terrestrial Communications Directorate

s/n Serial number

S/N Signal/Noise ratio

S/NR Signal/Noise Ratio

s/off Sign off

s/on Sign on

s/w software (computer programs and instructions)

S1 Adjutant (US Army)

S2 Intelligence Officer (US Army)

S3 Operations and Training Officer (US Army)

S3A Supervised Standard Scientific Analysis

S4 Supply Officer (US Army)

SA (1) South Atlantic

(2) Sand

(3) Situational Awareness

(4) Selective Activation (GPS)

(5) Selective Availability (GPS)

SAA South Atlantic Anomaly, a large magnetic deviation

SAAF Small Austere Air Field

SAAFR Standard use Army Aircraft Flight Route

SaaS Software as a Service

SABC South African Broadcasting Corporation

SABM Packet control frame: Set Async Balanced Mode (connect)

SAC Strategic Air Command, now part of US Stratcom

SACCS Strategic Automated Command & Control System

SACD Super Audio Compact Disk (Sony/Philips)

SACEUR Supreme Allied Command(er) Europe

SACLANT Supreme Allied Commander, Atlantic {NATO}

SADL Situational Awareness Data Link

SAE Self Addressed Envelope (usually with IRC or "green stamp")

SAFE Selected Area For Evasion

SAGE Semi-Automated Ground Environment (early, huge, USAF system)

SAID Sub-Auroral Ion Drift

SALS Short Approach Lighting System

SAM (1) Special Air Mission (US Air Force VIP flight)

(2) South America (MWARA)

(3) Surface-to-Air missile

SAMCOM Special Air Missions Communications ("Mystic Star")

SAME Specific Area Message Encoding (US weather warnings)

SANA Syrian Arab News Agency

SAO (1) South Atlantic Ocean

(2) Surface Aviation Observation (weather)

SAP (1) Second Audio Program

(2) Special-Access Program

(3) Soon As Possible, when every radio project has to be done

SAR (1) Search and rescue

(2) Synthetic Aperture Radar

(3) Station Availability Report (SHARES)

SARAH Standard Automated Remote to Autodin Host

SAREX Shuttle Amateur Radio Experiment, obsolete

SARNET NOAA SARSAT Network

SAROPS Search & Rescue Optimal Planning System

SARPs Standards and Recommended Practices

SARSAT Search And Rescue Satellite

SART (1) Survival Craft Radar Transponder

(2) Search And Rescue Transponder

SARTG Scandinavian Amateur Radio Teleprinter Group

SASE Self Addressed Stamped Envelope

SASP Separation and Airspace Safety Panel

SAT (1) South Atlantic (MWARA)

(2) Satellite

(3) Saturday

(4) Supervisory Audio Tone (telco)

SATAN Security Administrator Tool for Analyzing Networks

SATCOM Satellite communication

SATERN Salvation Army Team Emergency Radio Network

SAVASI Simplified Abbreviated Visual Approach Slope Indicator

SAWS Stand Alone Weather System

SB (1) Standby (EIA-449)

(2) Sierra Bravo, son of a [female dog]

(3) Sideband

SBA (1) Sovereign Base Area

(2) Small Business Administration

S-band 1.55-5.2 Ghz microwave band

SBAS (1) Space Based Augmentation System

(2) Satellite Based Augmentation System

SBCS Single Byte Character Set

SBD Safe Braking Distance (railroad)

SBD1 Safe Braking Distance + 1 minute (also SBD2, etc)

SBE Society of Broadcast Engineers

SBN Single sideBand phase Noise

SBS-1 Mode-S receiver by Kinetic Avionics

SBU Sensitive But Unclassified

SC (1) Sudden commencement (of a magnetic storm; causes fadeouts)

(2) Selective Calling

SC-104 Special Committee #104 (DGPS Standard)

SCA (1) Subsidiary Communications Authorization (US commercial FM)

(2) Shuttle Carrier Aircraft (NASA's modified 747 for transporting

orbiter)

SCADA Supervisory Control and Data Acquisition System

SCAMP Single-Channel Antijam Man-Portable

SCAT Strategic Communications (Continuing) Assessment Program

SCBA Self-Contained Breathing Apparatus

SCCS satellite communications control system

SCDCC Southern California Digital Communications Council (Amateur)

SCDX Sweden Calling DXers

SCDXC Southern California DX Club

SCFL Source-Coupled Field-effect transistor Logic

SCI San Clemente Island (USN, CA)

SCMA Southern California Monitoring Association

SCN (1) System Coordination Net (US Coast Guard)

(2) SHARES Coordination Net (US NCS/SHARES)

SCO (1) Subcarrier oscillator

(2) Santa Cruz Organization, a software source

(3) State Coordinating Officer (FEMA/NSEP)

SCOPE System Capable Of Planned Expansion (Scope Command)

SCP Southern Command Post, US Army, Camp Bondsteel, Kosovo

SCPC Single channel per carrier

SCPI Standard Commands for Programmable Instruments

SCPT Single channel per transponder

SCPTOC Southern Command Post Tactical Operations Center, Kosovo

SCR Silicon controlled rectifier

SCRAM Scramble; automated fast shutdown of nuclear reactor [~]

SCRRBA Southern California Repeater/Remote Base Assn (Amateur)

SCS Satellite Control Squadron

SCSI Small Computer System Interface ("scuzzy")

SCSL stratocumulus standing lenticular cloud

SCT Scattered clouds

SCTP Stream Control Transmission Protocol

SCUBA Self-Contained Underwater Breathing Apparatus

SD Secure Digital, type of storage device

SDARS Satellite Digital Audio Radio Service (Sirius & XM)

SDF Simplified Directional Facility

SDH Synchronous Digital Hierarchy (Europe)

SDHC SD card, High Capacity

SDI Strategic Defense Initiative, U.S. space money sink

SDIO SD card with I/O

SDLC Synchronous Data Link Control, bitwise computer comm protocol

SDLP Station Data Link Protocol

SDM Short Data Message

SDMA Space-Division Multiple Access

SDNRIU Secure Digital Net Radio Interface Unit

SDO Solar Dynamics Observatory (NASA)

SDR Software Defined Radio

SDRAM Synchronous Dynamic Random Access Memory

SDSC SD card, Standard Capacity

SDSL Symmetric Digital Subscriber Line

SDTV Standard Definition Television

SDU Secure data unit

SDX Semi-duplex

SDXC SD card, eXtended Capacity

SE Southeast

SEA Southeast Asia (MWARA)

SEAD Suppression of Enemy Air Defenses

SEAL Sea, Air, Land (US Navy special op teams)

SEAM Space Emergency Action Message

SEATO South East Asia Treaty Organization (now ASEAN)

sec Second

SEC Software Engineering Center (Army)

SECAF Secretary of the Air Force

SECAM (1) SEquentiel Couleur A Memoire, weird French TV standard,

adopted by Russian bloc to keep out Western TV

(2) Simply Everything Contrary to America

SECDEF Secretary of Defense (US)

SECT SHARES Emergency Coordination Team

SECURE State Emergency Capability Using Radio Effectively

SECURITE Prosign: safety traffic follows; uses FF pronunciation

SEE-CURE-EE-TAY

SEDENA Secretaria de la Defensa Nacional (Mexico)

SEE Stimulated Electromagnetic Emissions

SEI Specific Emitter Identification

SELCAL Selective Calling (tones or numbers) [~]

SELFEC Selective FEC

SELSCAN Proprietary name for Collins scanning ALE HF radio system

SENS System Event Notification Service (Windows)

SENSAPI System Event Notification Service API (nested acronym)

SENSE Synthetic Environments for National Security Estimates

SEP Solar Energetic Particle Event (observation interval)

SER Symbol Error Rate

SES Ship Earth Station

SESAR Single European Sky ATM Research

SESC Space Environmental Services Center

SESEF Ship Electronic Systems Evaluation Facility (US Navy)

SETI Search for Extra-Terrestrial Intelligence (by radio)

SEVOCOM Secure voice communications

SEW Space & Electronic Warfare

SF Special Facility