Technical Radio Operators Dictionary

The following is a searchable dictionary of commonly used phrases, acronyms, and abbreviations specific to the RF field

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z NUMBERS 0-9

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A (Alpha)
A Ampere ~ Unit Of Current Measurement. Current Is A Measure Of The Electron Flow Through A Circuit Per Unit Of Time.  6.24 X 10^18 Electrons Moving Past A Point In One Second, Equals One Ampere. Abbreviated As Amps. 
A Battery In Early Radio, Batteries Were The Prime Source Of Power, The "A" Battery Provided The Filament Voltage, The B-Battery Furnished The B+ Or The Voltage To The Plates Of The Tubes, And The C Battery Provided The Grid-Bias Voltage For The Tubes.  
absorption The Reduction In A Radio Signal Strength In The Ionosphere. 
AC Alternating Current 
access code  (Repeater Term) A Code To Activate A Repeater Function E.G. Auto Patch, Link Etc.. One Or More Numbers And/Or Symbols Are Keyed In With A Telephone Key Pad And Transmitted To The Repeater. 
A/D Analog-To-Digital 
Aerial Used In The Early Days Of Radio, Sometimes Referring To An Outdoor Antenna. Still Used In The United Kingdom. 
AF Audio Frequency 20 To 20,000 Hertz, The Human Hearing Range. Also Abbreviation For Africa 
AFC Automatic Frequency Control. Used In Fm Receivers To Prevent Drift. 
AFSK Audio Frequency Shift Keying (As Opposed To Frequency Shift Keying, FSK) 
A-index An Index Of The Conditions Of The Earth's Magnetic Field As Measured At Boulder, Colorado. Propagation Generally Improves With Lower Measurement Numbers.
amateur radio A Non-Commercial Radio Service As Set By A Recognized Cognizant Government Agency. In The USA, Amateur Radio Is Defined Under Part 97 Of The FCC Rules And Regulations
amateur service A Radio Communication Service For The Purpose Of Self-Training, Intercommunication And Technical Investigations Carried Out By Amateurs, That Is, Duly Authorized Persons Interested In Radio Technique Solely With A Personal Aim And Without Pecuniary Interest. 
ampere (A) The Basic Unit Of Electrical Current. Current Is A Measure Of The Electron Flow Through A Circuit Per Unit Of Time.  6.24 X 10^18 Electrons Moving Past A Point In One Second, Equals One Ampere. Abbreviated As Amps. 
AGC Automatic Gain Control. A Feedback Voltage In The Receiver Circuit To Prevent Fading.  ALC Automatic Level Control. A Feedback Voltage In The Transmitter's Output Amplifier Used To Prevent Amplifier Overload. Also Used As Feedback From A Linear Amplifier Back To The Exciter To Prevent Overdriving. 
alligator A Repeater That Transmits Further Than It Can Receive, Big Mouth, Small Ears! 
AM Amplitude Modulation
A.M. Ante Meridian (Before Noon)
amateur A Person Licensed To Operate In The Amateur Bands. 
AMSAT Radio Amateur Satellite Corporation
AMTOR Amateur Teleprinter Over Radio. A Version Of RTTY. 
ANARC Association Of North American Radio Clubs.
antenna A Device That Intercepts Or Radiates Radio Frequency Energy. 
antenna farm Ham's Dream - Lots of  Room For Big, Long, Antennas 
antenna tuner Impedance-Matching Device That Matches The Antenna System Input Impedance To The Transmitter, Receiver, Or Transceiver Output Impedance.  
appliance operator  Hams Who Neither Build Nor Experiment With Radio Equipment, But Merely Operate Commercial Equipment, Perhaps Without Understanding How It All Works. 
APRS Automatic Packet Position Reporting System
ARA Amateur Radio Association 
ARC Amateur Radio Club. Military Designation For Avionics (Aviation Radio Composite) 
ARES Amateur Radio Emergency Service
ARRL American Radio Relay League , The National Amateur Radio Organization In The USA
ARQ Automatic Repeat Request Used In AMTOR. 
ASCII American Standard Code For Information Interchange. The ASCII 7-Bit Code Represents 128 Characters Including 32 Control Characters. 
ASR Automatic Send-Receive. An RTTY Terminal Mode That Allows Message Composition While Receiving Text From The Another Station. 
ATT Attenuator, Often Expressed In Db Of Reduction. 
ATV Amateur Television, Also Known As Fast Scan Television
auroral propagation Propagation Above 30 MHz By Means Of Refraction By Highly Ionized Regions Around The Earth's Poles.
autopatch (Repeater Term) A Device That Interfaces A Repeater To The Telephone System To Permit Repeater Users To Make Telephone Calls. Often Just Called A "Patch." 
AVC Automatic Volume Control feedback Scheme To Level Out The Receiver Audio Volume. 
AWG American Wire Gauge Standard For Describing The Diameter Of Wire By Which The Wire Size Increases As The Gauge Number Decreases. 
  
B (Bravo)   
B Battery - In Early Radio, Batteries Were The Prime Source Of Power. The A Battery Provided The Filament Voltage, The B Battery Furnished The B+ Or The Voltage To The Plates Of The Tubes, And The C Battery Provided The Grid-Bias Voltage To The Tubes.
balanced line A Feed Line With Two Conductors Having Equal But Opposite Voltages, With Neither Conductor At Ground Potential.  
balanced modulator A Mixer Circuit Used In A Single-Sideband Suppressed-Carrier Transmitter To Combine A Voice Signal And The RF Carrier. The Balanced Modulator Isolates The Input Signals From Each Other And The Output, So That Only The Sum And The Difference Of The Two Input Signals Reach The Output. The Original Carrier Signal And The Audio Signal Are Suppressed. 
balun Balance To Unbalance , A Device Used To Couple A Balanced Antenna To An Unbalanced Feed Line (E.G., Dipole To Coax)   
band A Range Of Frequencies Allotted For A Particular Use (E.G., 20 Meter Band)
bandpass Range Of Frequencies Permitted To Pass Through A Filter Or Receiver Circuit. 
band-pass filter A Circuit That Passes A Range Of Frequencies And Attenuates Signals Above And Below This Range 
base A Radio Station Located At A Fixed Location As Opposed To A Mobile. Used To Identify The Control Location In A Network Of Radio Stations. 
barefoot Transmitting With A Transceiver Alone And No Linear Amplifier 
base loading A Loading Coil At The Bottom Of An Antenna To Achieve A Lower Resonant Frequency. 
BAUD The Unit Of Digital-Signal Speed. 
Baudot A Five-Bit Digital Code Used In Teleprinter Application. 
BBC British Broadcasting Corporation.
BBS Bulletin Board System 
BCI Broadcast Radio Interference. 
beam An Antenna That Gives A Directional Beam Pattern. See Yagi 
beacon A Station That Transmits One-Way Signals For The Purpose Of Navigation, Homing, And Propagation Condition Determination. See URL ACONS 
Benton Harbor Lunch Box A Portable Transceiver Made By Heathkit Co. Band Choices Were 2, 6, Or 10 Meters  Operation.  
BFO Beat Frequency Oscillator. Used To Mix With The Incoming Signal To Produce An Audio Tone For CW Reception. A BFO Is Needed To Copy CW And SSB Signals. 
Bird Nickname For Satellite. Also A Brand Name Of A High-End, High Quality Directional Wattmeter.  
birdie Spurious Signals Produced In A Receiver usually A Product Of Mixed Intermediate Frequencies Within The Radio. 
bleed over Interference Caused By A Station Operating On An Adjacent Channel 
bleeder resistor A Large-Value Resistor Connected Across The Filter Capacitor In A Power Supply To Discharge The Filter Capacitors When The Supply Is Turned Off. 
block diagram A Drawing Using Rectangles To Represent Major Sections Of Electronic Circuits. The Diagram Shows Signal Flow And The Function Of The Sections. 
BNC Coax Connector Commonly Used With VHF/UHF Equipment - Bayonet Niell-Concelman (Standard Connector Type Used On Coax Cable, Named For Its Inventors). 
bps Bits Per Second 
BPSK Binary Phase Shift Keying; Digital DSB Suppressed Carrier Modulation. 
birdie A False Or Spurious Signal In A Receiver Inadvertently Produced By The Receiver's Circuitry. 
boat anchor Antique Ham Equipment - So Named Because Of Weight And Size.
bootlegger Someone, Usually Not A Ham But A Wannabe, Making Up A Callsign, One Usually Not In The Callbook, And Getting On The Air. Sometimes It Is Someone Who Already Bought A Radio, Took The Test And Flunked, And Then Gets On The Air Anyway. 
bounce Reflections Of A Radio Wave Off Of An Object, (E.G., The Ionosphere Or The Moon) 
breadboard Early Experimenters Used A Wood Board Or Bread Board To Lay Out Circuits. Now Used To Describe An Experimental Layout On Whatever Media - Like Pc Boards. 
break (Repeater Term)  Used To Interrupt A Conversation On A Repeater To Indicate That There Is An Emergency Or Urgent Message. If Non-Urgent, Simply Interject Your Callsign. 
break break (Repeater Term) Used To Intercede In An Existing Conversation With Emergency Communications. 
broadcasting Transmissions Intended For The General Public. Broadcasting Is Prohibited On The Amateur Radio Bands, Other Than QST's Which Of Are Of Interest To All Amateur Stations, Example W1Aw Code Practice Transmissions. 
bug A Semi-Automatic Mechanical Code Key 
bunny hunt (See "Fox Hunt")
bureau International Amateur Organizations Set Up To Process QSL Cards Between Countries. Provides An Inexpensive Way To Send And Receive QSL Cards
burro International QSL Forwarding Bureau. 
  
C (Charlie) 
C Battery In Early Radio, Batteries Were The Prime Source Of Power A Battery Provided The Filament Voltage, The B Battery Furnished The B+ Or Voltage To The Plates Of The Tubes, And The C Battery Provided The Grid-Bias Voltage To The Tubes. 
California kilowatt A Power Setting Above The Legal Limit 
call book A Publication Or CD Rom That Lists Licensed Amateur Radio Operators
calling frequency A Defacto Standard Frequency Where Stations Attempt To Contact Each Other. Example - 146.52 Is The USA National Fm Simplex Calling Frequency.
candy store Ham Term For The Local Ham Radio Dealer.
cans Headphones 
cap Capacitor (Formerly Condenser) 
CAP Civil Air Patrol 
capacitor An Electronic Component Composed Of Two Or More Conductive Plates Separated By An Insulating Material. A Capacitor Stores Energy In An Electric Field. 
carrier A Pure Continuous Radio Emission At A Fixed Frequency, Without Modulation And Without Interruption. Several Types Of Modulation Can Be Applied To The Carrier, See Am And Fm.
carrier-operated relay (COR) (Repeater Term) Circuitry That Causes The Repeater To Transmit In Response To A Received Signal. 
CATV Cable Television (Originally Community Television) 
CATVI Cable Television Interface. 
CBA Callbook Address 
CC&R's Covenants, Conditions, And Restrictions Extensive Set Of Rules Drawn Up By Homeowner's Associations And Their Lawyers Which, Among Other Things, Typically Restrict Or Completely Prohibit A Homeowner From Having Most Forms Of Antennas On Their Property. 
CCW Coherent CW 
center frequency The Unmodulated Carrier Frequency Of An Fm Transmitter. 
center loading A Loading Coil At The Center Of An Antenna To Achieve A Lower Resonant Frequency 
centi The Metric Prefix For 10^-2, Or Divide By 100. 
channel (Repeater Term) The Pair Of Frequencies  (Input And Output) Used By A Repeater. 
chassis ground The Common Connection For All Parts Of A Circuit That Connect To The Negative Side Of The Power Supply. 
chirp Changes In The Carrier Frequency Of A CW Transmitter, Resulting In A Chirping Sound 
clear Used To Indicate A Station Is Done Transmitting 
closed repeater (Repeater Term) A Repeater Whose Access Is Limited To A Select Group (See Open Repeater). 
cloud warmer An Antenna Which Radiates Most Of The Transmitted Energy Nearly Straight Up. 
CMOS Complementary-Symmetry Metal-Oxide Semiconductor. 
coax, coaxial cable A Type Of Wire That Consists Of A Center Wire Surrounded By Insulation And Then A Grounded Shield Of Braided Wire. The Shield Minimizes Electrical And Radio Frequency Interference. 50-Ohm And 72 Ohm Characteristic Impedances Are Typical.
code Usually Refers To Morse Code, But Used For Others Such As Baudot. 
coil A Conductor Wound Into A Series Of Loops. See Also Inductor 
color code A System In Which Numerical Values Are Assigned To Various Colors. Colored Stripes Are Painted On The Body Of Resistors And Other Components To Show Their Value. See Color Code 
condenser Old Term For Capacitorsic Unit Is Farads, Which Is Generally Too Large So Usually Expressed In Microfarads Or Pico farads. An Electronic Component Composed Of Two Or More Conductive Plates Separated By An Insulating Material. A Capacitor Stores Energy In An Electric Field. 
controller (Repeater Term)  Control System Within A Repeater -  Usually Includes Turning The Repeater On-Off, Timing Transmissions, Sending The Identification Signal, Controlling The Auto Patch And CTCSS Encoder/Decoder. 
control operator (Repeater Term) The Amateur Radio Operator Designated To "Control" The Operation Of The Repeater, As Required By FCC Regulations. 
copy Indication Of How Well Communications Are Received. "I Have A Good Copy On You" Also Used As A Question, As In "Did You Copy" or "Understand All" 
copying Used To Indicate One Is Monitoring As In "I Was Copying The Mail" Which Means I Was Listening In On The Conversation 
core The Material Used In The Center Of An Inductor Coil, Where Magnetic Fields Is Concentrated. 
courtesy beep (Repeater Term) An Audible Indication That A Repeater User May Go Ahead And Transmit, Usually Resets The Timer 
coverage (Repeater Term) The Geographic Area That The Repeater Provides Communications. 
CPS Cycles Per Second, This Terminology Was Replaced By "Hertz" (See "Hertz") 
CQ Calling Any Amateur Radio Station, May Be Sent In CW, Phone Or Some Digital Modes 
CR Carriage Return 
critical angle The Angle At Which A Radio Signal Is Refracted In The Ionosphere. Lower Angles Generally Result In Greater Distance Transmissions. 
critical frequency The Highest Frequency At Which A Vertically Incident Radio Wave Will Return From The Ionosphere. Above The Critical Frequency Radio Signals Pass Through The Ionosphere Instead Of Returning To Earth. 
cross-band The Process Of Transmitting On One Band And Receiving On Another. 
CRT Cathode-Ray Tube 
crystal A Piezoelectric Device That Tends To Resonate At A Frequency Dependent On Its Material, Dimensions, And Temperature 
crystal filter A Network Of Piezoelectric Crystals Used To Obtain High Rejection Of Unwanted Signals. 
crystal oscillator A Device That Uses A Quartz Crystal To Keep The Frequency Of A Transmitter Constant. 
CSCE Certificate Of Successful Completion Of Examination (U.S.), A Certificate Certifying A Person Has Successfully Passed One Or More Of The Amateur Radio License Examinations 
CTCSS (Repeater Term) Abbreviation For Continuous Tone-Controlled Squelch System, A Series Of Sub Audible Tones That Some Repeaters Use To Restrict Access. See CTCSS Codes 
current A Flow Of Electrons In An Electrical Circuit. 
cutoff frequency The Frequency At Which A Filter Will Begin To Reject Signals. 
CW Continuous Wave, See Carrier. In Truth A Continuous Wave Is An Unmodulated, Uninterrupted RF Wave. However In Common Usage Refers To Morse Code Emissions Or Messages Which Is An Interrupted Wave.
cycles (cps) Term Used For Measuring Frequency Prior To The Term Hertz Replaced Itnce Kc, Mc, Etc. 
   
D (Delta) 
dB Decibel (1/10 Of A Bel); Unit For The Ratio Of Two Power Measurements.
dBc In Terms Of Rf Signals, Dbc Is Decibels Relative To The Carrier Level. 
dBd Decibels Above Or Below A Dipole Antenna. 
dBi Decibels Above Or Below An Isotropic Antenna. 
DC Direct Current 
de Morse Code For "From" E.G., Ac6V De Wa0Ppp 
deci The Metric Prefix For 10^-1, Or Divide By 10. 
delta-loop antenna A Variation Of The Cubical Quad With Triangular Elements. 
desense (desensitization) The Reduction Of Receiver Sensitivity Due To Overload From A Nearby Transmitter. 
detecto The Stage In A Receiver In Which The Modulation (Voice Or Other Information) Is Recovered From The Rf Signal. Called A Discriminator In Fm 
deviation The Change In The Carrier Frequency Of A Fm Transmitter Produced By The Modulating Signal. 
deviation ratio The Ratio Between The Maximum Change In Rf-Carrier Frequency And The Highest Modulating Frequency Used In An Fm Transmitter. Also See Modulation Index. 
digipeater A Store-And-Forward Digital Repeater Which Will Receive And Transmit A Data Packet On The Same Frequency. 
dip meter Or Grid Dip Meter - A Device Used To Determine The Resonant Frequency Of An Electronic Circuit 
diplexer  A Frequency Splitting And Isolation Device. Typically Used To Couple Two Transceivers To A Single Or Dual Band Antenna , Thus Allowing One To Receive On One Transceiver And Transmit On The Other Transceiver. Typical Application 2M And 440Mhz Transceivers Into A Dual Band Antenna For Satellite Work.
dipole  The Basic Antenna Consisting Of A Length Of Wire Or Tubing, Open And Fed At The Center. The Entire Antenna Is ½ Wavelength Long At The Desired Operating Frequency. This Antenna Often Used As A Standard For Calculating Gain, Dbd. 
director An Element In Front Of The Driven Element In A Yagi Or Quad And Some Other Directional Antennas.  
doubling (Repeater Term) On A Repeater If Two Stations Transmit Simultaneously, The Signals Mix In The Repeater's Receiver And Results In A Raspy Signal. Fm Has A Characteristic Whereby The Stronger Signals "Captures" And Over-Rides The Weaker One. 
downlink Channel Used For Satellite-To-Earth Communications. 
double-pole, double-throw (DPDT) Switch With Two Different Circuit Lines To Two Different Points.
double-pole, single-throw (DPST) Switch With Two Different Circuit Lines On Or Off.  
DPSK Differential Phase Shift Keying; A Form Of BPSK Where Only Data Transitions Are Transmitted. 
D-region D-Layer Lowest Region Of The Ionosphere Found Approximately 25 To 55 Miles Above Earth; It Fades Away Quickly After Sunset And Sometimes Does Not Form At All On Short Winter Days. The Main Impact Of The D-Layer On Radio Propagation Is To Absorb Energy From Signals Passing Through It.
driven element Antenna Element That Connects Directly To The Feed Line.  
dropping out  (Repeater Term) A Repeater Requires A Minimum Signal In Order To Transmit, When A Signal Does Not Have Enough Strength To Keep The Repeater Transmitting, It "Drops Out" 
DSP Digital Signal Processing Slows For Filtering, Noise Reduction, Audio Equalization, Etc 
DTMF (Repeater Term) Abbreviation For Dual-Tone Multi-Frequency, The Series Of Tones Generated From A Keypad On A Ham Radio Transceiver (Or A Regular Telephone).  Uses 2-Of-7 Or 2-Of-8 Tones; Often Referred To By Bell's Trademark Touchtone. See DTMF Tones 
dual-band antenna  Antenna Designed For Use On Two Different Amateur Radio Bands. 
dummy load A Device Which Substitutes For An Antenna During Tests On A Transmitter. It Converts Radio Energy To Heat Instead Of Radiating Energy. Offers A Match To The Transmitter Output Impedance. 
duplex (Repeater Term) A Communication Mode In Which A Radio Transmits On One Frequency And Receives On Another (Also See Full Duplex, Half Duplex, And Simplex) 
duplexer (Repeater Term) A Device Used In Repeater Systems Which Allows A Single Antenna To Transmit And Receive Simultaneously 
DVM Digital Voltmeter 
DX (Noun) Distant Station; (Verb) To Contact A Distant Station 
DX'er An Amateur Radio Operator Who Actively Pursues Contacting Distant And Rare Amateur Radio Stations. Also Applied To Short Wave Listeners. 
DXCC Award Offered By Arrl For Contacting And Confirming 100 Or More Different Countries First Introduced In 1937.    DXCC Is Copyright ARRL And Its Use Here Is Printed With Permission Of The ARRL. See DXCC 
DXpedition Radio Expedition To Remote And Rare Locations
dynamic range How Well A Receiver Can Handle Strong Signals With Overloading; Any Measure Of Over 100 Decibels Is Considered Excellent. 
  
E (Echo) 
earth ground A Circuit Connection To A Ground Rod Driven Into The Earth 
ECSSB Exalted-Carrier Single Sideband. 
Edison Effect Thomas A. Edison Discovered The Electron Flow From A Glowing Cathode To An Anode In An Evacuated Glass Bulb And Was Called The 'Edison-Effect' This Led To The Development Of The Vacuum Tube. 
EEPROM Electrically-Erasable Programmable Read-Only Memory 
E-layer The Region Of The Ionosphere Found Approximately 55 To 90 Miles Above Earth; It Fades Away A Few Hours After Sunset. The Main Impact Of The E-Layer On Radio Propagation Is To Absorb Energy From Signals Passing Through It, Although Sporadic-E Propagation Makes Possible Distant Communications On Frequencies Above 30 MHz.
EHF Extremely High Frequency (300 GHz) 
EIRP Effective Isotropic Radiated Power. 
elephant A Repeater That Receives Further Than It Can Transmit, Big Ears, Small Mouth! 
ELF Extremely Low Frequency (300 Hz) 
Elmer A Mentor; An Experienced Operator Who Tutors Newer Operators See Elmer's 
eleven meters Currently The Cb Band, Once A Ham Band 
EME Earth-Moon-Earth; Using The Moon As A Passive Reflector To Establish A Signal Path; Moon bounce.
EMF Electromotive Force; Voltage. 
EMI Electromagnetic Interference. 
emission mode The Form Of A Radio Emission, Such As Am, Fm, Or Single Sideband.
EMP Electromagnetic Pulse; A Extremely High-Energy Magnetic Field. Such As The Current Flow Caused By A Lightning Strike Or Nuclear Explosion. 
ERP Effective Radiated Power 
E-skip Sporadic E-Layer Ionospheric Propagation
ether Old Theory For The Medium Once Believed To Conduct Radio Waves. The Existence Of The  Ionosphere Is First Discovered By The English Physicist, Appleton In 1924. 
EU Europe 
eyeball A Face-To-Face Meeting Between Two Ham Radio Operators. 
  
F (Foxtrot) 
FAA Federal Aviation Administration (USA). See FAA 
F-layer The Region Of The Ionosphere Found Approximately 90 To 400 Miles Above Earth And Which Is Responsible For Most Long Distance Propagation On Frequencies Below 30 MHz. During The Daytime (Especially In Summer), Solar Heating Can Cause The F-Layer To Split Into Two Separate Layers, The F1-Layer And The F2-Layer.
FAQ Frequently Asked Questions 
far field of an antenna That Region Of The Electromagnetic Field Surrounding An Antenna Where The Field Strength As A Function Of Angle (The Antenna Pattern) Is Essentially Independent Of The Distance From The Antenna. In This Region (Also Called The Free-Space Region), The Field Has A Predominantly Plane-Wave Character. That Is, Locally Uniform Distributions Of Electric Field Strength And Magnetic Field Strength Are In A Plane Perpendicular To The Direction Of Propagation. 
Farnsworth A Method Of Sending Morse Code Characters. Example Characters Are Sent At 13 Words Per Minute But The Spacing Is Adjusted So That The Overall Code Speed Is 5 Words Per Minute. 
fax Facsimile, A Digital Mode For Transmitting Images.
FB Fine Business, Good, Fine, Ok 
FCC Federal Communications Commission, The Governmental Body In The U.S. Which Regulates The Radio Spectrum See Urlc 
feedline Wire Or Cable Connecting A Radio To An Antenna 
FET Field-Effect Transistor 
field day Amateur Radio Activity In June To Practice Emergency Communications. 
field strength meter A Test Instrument Used To Show The Presence Of Rf Energy And The Relative Strength Of The Rf Field. 
filter A Circuit Or Device That Will Allow Certain Frequencies To Pass While Rejecting Others. 
final The Last Transmission By A Station During A Contact. Also The Last Amplifying Stage Of A Radio Transmitter. 
fire bottle Any Electronic Vacuum Tube 
first personal First Name  Jargon That Has Crept Into Ham Jargon Old Timers Shutter 
fist Early Spark Transmitters Showered The Operator With Sparks  Marconi's Key Lever Was Lengthened And The Padded End Was Beaten With The 'Fist' Of The Operator To Send Dots And Dashes. Also A Cw Ops' Reference To Another Ops' Keying Characteristic 
F.I.S.T.S. An Organization Of Cw Enthusiasts. See Fists 
flat topping Over modulating So As To Distort A Waveform 
flutter Rapid Variation In The Signal Strength Of A Station, Usually Due To Propagation Variations. 
FM Frequency Modulation
FOC First Class CW Operators Club - See FOC 
fox hunt A Contest To Locate A Hidden Transmitter.
frequency The Rate Of Oscillation (Vibration). Audio And Radio Wave Frequencies Are Measured In Hertz. (Cycles Per Second) 
frequency coordinator (Repeater Term) An Individual Or Group Responsible For Assigning Frequencies To New Repeaters Without Causing Interference To Existing Repeaters 
FSK Frequency-Shift Keying. Modulating The Transmitter By Using The Rtty Data Signal To Shift The Carrier Frequency. Mark And Space. See Url Modulating Tones
FSTV Fast-Scan Tv. Same As Commercial Broadcast Tv. 
full-break in (QSK)  Allows A Station To Break Into The Communication Without Waiting For The Transmitting Station To Finish. 
full duplex A Communications Mode In Which A Radios Can Transmit And Receive At The Same Time By Using Two Different Frequencies (See "Duplex" And Half Duplex) 
full gallon (See Gallon) 
full quieting (Repeater Term) A Phenomenon On Fm Transmissions Where The Incoming Signal Is Sufficient To Engage The Receiver Limitersus Eliminating The Noise Due To Amplitude Fluctuations. 
full-wave bridge rectifier A Full-Wave Rectifier Circuit That Uses Four Diodes And Does Not Require A Center-Tapped Transformer. Converts Ac To Dc
full-wave rectifier A Circuit Basically Composed Of Two Half-Wave Rectifiers. The Full Wave Rectifier Allows The Full Ac Waveform To Pass Through; One Half Of The Cycle Is Reversed In Polarity. This Circuit Requires A Center-Tapped Transformer. Converts Ac To Dc
fuse A Thin Metal Strip Mounted In A Holder. When Excessive Current Passes Through The Fuse, The Metal Strip Melts And Opens And Protects The Circuit. Fuses Are Rated In Amperes And Voltage And Time To Activatest Blow Or Slow Blow. 
  
G (Golf) 
gallon Slang For Transmitter Output Power - Legally Either 1000 Watts Cw Or 1500 Watts Pep 
GaAs Gallium Arsenide; Used In High-Speed Semiconductors. 
gain, antenna  An Increase In The Effective Power Radiated By An Antenna In A Certain Desired Direction, Or An Increase In Received Signal Strength From A Certain Direction. This Is At The Expense Of Power Radiated In, Or Signal Strength Received From, Other Directions. 
GHz Gigahertz (1,000,000,000) Hertz (See Hertz) 
Giga  The Metric Prefix For 10^9 Or Times 1,000,000,000. 
GMRS General Mobile Radio Service.
gray line A Band Around The Earth That Separates Daylight From Darkness. It Is A Transition Region Between Day And Night. One Of The Many Types Of Propagation Paths. 
great circle route The Shortest Path By Radio Between Any Two Points On Earth. 
green stamp U.S. Dollar Bill Sent Along With A Qsl Card (Instead Of An Irc) To Offset Postage Costs Of A Return Card.  
grid dip meter Test Equipment That Causes A Meter Decrease (Dip) When Near Resonant Circuits 
ground Common Zero-Voltage Reference Point. 
ground-plane antenna A Vertical Antenna Built With The Central Radiating Element One-Quarter-Wavelength Long And Several Radials Extending Horizontally From The Base. The Radials Are Slightly Longer Than One-Quarter Wave, And May Droop Toward The Ground. 
ground wave propagation Radio Waves That Travel Along The Surface Of The Earth, Even Beyond The Horizon.
  
H (Hotel) 
half duplex (Repeater Term) A Communications Mode In Which A Radio Transmits And Receives On Two Different Frequencies But Performs Only One Of These Operations At Any Given Time (See "Duplex" And "Full Duplex") 
half-wave dipole The Basic Antenna Consisting Of A Length Of Wire Or Tubing, Open And Fed At The Center. The Entire Antenna Is ½ Wavelength Long At The Desired Operating Frequency.
half-wave rectifier A Circuit That Allows Only Half Of The Applied Ac Waveform To Pass Through It. 
hand-held (Repeater Term) A Small, Lightweight Portable Transceiver Small Enough To Be Carried Easily; Also Called Ht (For Handie-Talkie, A Motorola Trademark). 
hang time (Repeater Term) The Short Period Following A Transmission That Allows Others Who Want To Access The Repeater A Chance To Do So; A Courtesy Beep Sounds When The Repeater Is Ready To Accept Another Transmission. 
ham An Amateur Radio Operator. 
hamfest Ham Festival, A Social And Commercial Event At Which Hams Meet To Buy, Sell, And Swap Equipmente.  See Hamfests
handle A Radio Operator's Name. Actually Unnecessary - Just Say The Name Is. But Many Old Timers Use Handle. 
harmonic A Signal At A Multiple Of The Fundamental Frequency. Also A Slang Term For The Children Of An Amateur. 
HDTV High Definition Television 
HDX Half-Duplex. A Communication System In Which Stations Take Turns Transmitting And Receiving. 
Hertz The Standard Unit Used To Measure Frequency (One Hertz Equals One Complete Cycle Per Second) 
HF High Frequency 3 MHz To 30 MHz 
hi hi Ha Ha (Laughter) 
high-pass filter A Filter Designed To Pass High Frequency Signals, While Blocking Lower Frequency Signals. 
homebrew Term For Home-Built, Noncommercial Radio Equipment. 
hop Communication Between Stations By Reflecting The Radio Waves Off Of The Ionosphere. 
horizontally polarized wave An Electromagnetic Wave With Its Electric Lines Of Force Parallel To The Ground. 
HT (Repeater Term) Handi-Talkie small Hand Held Radio 
Hz (See Hertz) 
  
I (India) 
I (intensity) Symbol For Current In An Electric Circuit, Measured In Amperes 
IARU International Amateur Radio Union Worldwide Ham Radio Organization Whose Members Consist Of The Official Radio Society From Each Participating Country. See Iaru 
IC Integrated Circuit. 
ID Identification, As Announcing Station Callsign At Intervals Specified By Part 97 Of The FCC Rules And Regulations. 
IF Intermediate Frequency - Intermediate Frequency, Resultant Frequency From Heterodyning The Carrier Frequency With An Oscillator, Mixing Incoming Signals To An Intermediate Frequency Enhances Amplification, Filtering And The Processing Signals. Desirable To Have More Than One If. 
image A False Signal Produced In A Superheterdyne Receiver's Circuitry. 
impedance The Opposition To The Flow Of Electric Current And Radio Energy; It Is Measured In Ohms (Symbol Is Z). For Best Performance, The Impedance Of An Antenna, The Feedline, And The Antenna Connector On A Radio Should Be Approximately Equal. 
inductance A Measure Of The Ability Of A Coil To Store Energy In A Magnetic Field. 
inductor An Electrical Component Usually Composed Of A Coil Of Wire Wound On A Central Core. An Inductor Stores Energy In A Magnetic Field.  
input frequency (Repeater Term) The Frequency Of The Repeater's Receiver (And Your Transceiver's Transmitter). 
intermod Short For "Intermodulation," This Means False Or Spurious Signals Produced By Two Or More Signals Mixing In A Receiver Or Repeater Station. 
intermodulation distortion or IMD (Repeater Term) The Unwanted Mixing Of Two Strong Rf Signals That Causes A Signal To Be Transmitted On An Unintended Frequency. 
I/O Input/Output 
ionosphere The Electrically Charged Region Of The Earth's Atmosphere Located Approximately 40 To 400 Miles Above The Earth’S Surface That Refracts Radio Signals. 
IOTA Islands On The Air
IRC International Reply Coupon Coupon That Can Be Purchased At Post Offices Which Can Be Exchanged In Foreign Countries For Return Postage For A Surface Mail Letter To The Country That Issued The Coupon.
isotropic Theoretical "Single Point" Antenna Used Calculate Gain. 
ITU International Telecommunications Union, The Body Which Specifies Worldwide Guidelines Concerning The Use Of The Electromagnetic Spectrum For Communications Purposes. See Itu 
  
J (Juliet) 
J antenna (J pole) A Mechanically Modified Version Of The Zepp (Zeppelin) Antenna. It Consists Of A Half-Wavelength Radiator Fed By A Quarter-Wave Matching Stub. This Antenna Does Not Require The Ground Plane That ¼-Wave Antennas Do To Work Properly. 
jam Cause Intentional Interference 
JFET Junction Field-Effect Transistor. 
jug Large Transmitting Tubes, Klystrons, Magnetrons 
jury rig Fix In An Unorthodox Manner 
  
K (Kilo) 
kc (See "Kilocycles") 
kilo The Metric Prefix For 10^3, Or Times 1,000 
K- index A Measure Of The Earth's Magnetic Field As Measured At Boulder, Colorado. Propagation Conditions Improve With Lower Measurement Numbers.
kerchunking Activating A Repeater Without Identifying Or Modulating The Carrier. 
key (Noun) Any Switch Or Button, Usually Refers To A Telegraph Or Morse Code Key 
key (Verb) To Press A Key Or Button 
keyer Electronic Device For Sending Morse Code Semi-Automatically; Connects To A Key (See Above). Dits Are Sent By Pressing One Paddle Of The Key, Dahs Sent By Pressing The Other One Paddle. 
key up (Repeater Term) To Turn On A Repeater By Transmitting On Its Input Frequency. 
key up (Verb) To Activate A Transmitter Or Repeater 
kilocycles Thousand Cycles Per Second. Replaced By Kilohertz (KHz) 
kilohertz One Thousand Hertz (See "Hertz") 
  
L (Lima) 
ladder line An Open Wire Transmission Line - 600, 450 Ohm Characteristic Impedances Are Typical. 
landline Ham Slang For Telephone (Lines)
LCD Liquid Crystal Display 
LED Light-Emitting Diode 
LF Low Frequency KHz To 300 KHz 
lid A Poor Operator, One Who Does Not Follow Proper Procedures Or Sends Sloppy Morse Code. 
limiter (Repeater Term) A Stage Of An Fm Receiver That Clips The Tops Of The Fm Signal Thus Makes The Receiver Less Sensitive To Amplitude Variations And Pulse Noise.  
linear An Amplifier Used After The Transceiver Output. So Named For Its Purity Of Amplification. Linear, In The Mathematical Sense, Means That What Comes Out Is Directly Proportional To What Goes In. As Far As Linear Amps Go, If You Double The Input, The Output Is Doubled And So On. This Does Not Generate Any Additional Frequency Byproducts. If The Amp Is Nonlinear, Sums, Differences And All Combinations Of Those Are Generated Also. 
line-of-sight propagation The Term Used To Describe Propagation In A Straight Line Directly From One Station To Another.  
load An Electrical Device Which Consumes, Converts, Or Emanates Energy 
local oscillator (LO) A Receiver Circuit That Generates A Stable, Pure Signal Used To Mix With The Received Rf To Produce A Signal At The Receiver Intermediate Frequency (If). 
long path Short Path Degrees The Direct Great Signal Bearing Path Between Two Locations. Long Path Is The Reciprocal Bearing. 
lollipop Ham Term For An Astatic D-104 Microphone 
LORAN Long Range Aid To Navigation. 
lowfer One Who Experiments At Very Low Frequencies (Typically 1750 Meters, Which Is 160-190 KHz And Can Be Used Under FCC Part 15). 
low-pass filter A Filter That Allows Signals Below The Cutoff Frequency To Pass Through And Attenuates Signals Above The Cutoff Frequency.  
LSB Lower Side Band -The Common Single-Sideband Operating Mode On The 40, 80, And 160 Meter Amateur Bands.  
LW Long Wave 1500 KHz 
  
M (Mike) 
mA milliampere (1/1,000 ampere) 
machine A Repeater 
magnetic mount or mag-mount (Repeater Term) An Antenna With A Magnetic Base That Permits Quick Installation And Removal From A Motor Vehicle Or Other Metal Surface. 
mA/h Milliampere Per Hour 
making the trip Jargon For "Successfully Transmitting A Readable Message" 
MARS Military Affiliate Radio System, Military Affiliated Amateurs Who Provide Free Communications For Overseas GIS And Other Federal Services. Mars Operators Are Licensed Under Dod. Established 1948. 
matchbox Normally Called An Antenna Tuner. Impedance-Matching Device That Matches The Antenna System Input Impedance To The Transmitter, Receiver, Or Transceiver Output Impedance.  
MC (See Megacycles) 
MCW Modulated Continuous Wave, A Fixed Audio Tone Modulates A Carrier, Older Method Of Sending Morse Code.
mega The Metric Prefix For 10^6, Or Times 1,000,000. 
megacycles Million Cycles Per Second. This Terminology Has Been Replaced By Megahertz (Mhz) 
megahertz Million Hertz (See Hertz) 
meteor scatter Ionized Trails Of Meteors Used As A Reflecting Media.
MF Medium Frequency00-3,000 KHz) 
mic (mike) Microphone device That Converts Sound Waves Into Electrical Energy. 
micro The Metric Prefix For 10^-6, Or Divide By 1,000,000. 
microwave The Region Of The Radio Spectrum Above 1 Gigahertz (Ghz). 
mil 1/1000 Of An Inch. Also Mill A Special Typewriter Used By Radio Operators In Copying Messages 
milli The Metric Prefix For 10^-3, Or Divide By 1,000. 
mixer A Circuit That Takes Two Or More Input Signals, And Produces An Output That Includes The Sum And Difference Of Those Signal Frequencies. 
mW Milliwatt (1/1,000 Watt) 
mobile An Amateur Radio Station Installed In A Vehicle mobile Station Can Be Used While In Motion. A Portable Station Is One That Is Designed To Be Easily Moved From Place To Place But Can Only Be Used While Stopped.  
mode (See Emission Mode) 
modem Short For Modulator/Demodulator. A Modem Modulates A Radio Signal To Transmit Data And Demodulates A Receive Signal To Recover Transmitted Data. 
modulate Create A Radio Emission So That It Contains Information (Voice, Morse Code, Music, Binary, ASCII).
modulation Index (Repeater Term) The Ratio Between The Maximum Carrier Frequency Deviation And The Audio Modulating Frequency At A Given Instant In An Fm Transmitter. 
MOSFET Metal-Oxide-Semiconductor-Field-Effect Transistor 
motorboating An Undesirable Low Frequency Feedback Resulting In A Motorboat Sound On The Audio 
MUF Maximum Usable Frequency, A Measure Of The Highest Frequency That Will Support Transmissions Off Of The Ionosphere. 
multimode transceiver Transceiver Capable Of SSB, CW, Am, And Fm Operation.  
mV Millivolt (1/1,000 Volt) 
MW Medium Wave ~ 3000 KHz. Also Used For The Am Broadcast Band 530-1710 Khz 
  
N (November) 
NB Narrow Band. Also Noise Blanker 
NBFM  Narrow Band Fm 
NCS Net Control Station  
near field of an antenna The Region Of The Electromagnetic Field Immediately Surrounding An Antenna Where The Reactive Field Dominates And Where The Field Strength As A Function Of Angle (Antenna Pattern) Depends Upon The Distance From The Antenna. It Is A Region In Which The Electric And Magnetic Fields Do Not Have A Substantial Plane-Wave Character, But Vary Considerably From Point-To-Point. 
negative No, Incorrect 
negative copy Unsuccessful Transmission 
negative feedback The Process In Which A Portion Of The Amplifier Output Is Returned To The Input, 180 Degrees Out Of Phase With The Input Signal. Improves Linearity And Reduces Distortion. 
negative offset The Repeater Input Frequency Is Lower Than The Output Frequency. 
net A Group Of Stations That Meet On A Specified Frequency At A Certain Time. The Net Is Organized And Directed By A Net Control Station, Who Calls The Net To Order, Recognizes Stations Entering And Leaving The Net, And Authorizes Stations To Transmit. 
NiCad Nickel Cadmium, Generally Refers To A Type Of Rechargeable Battery 
nickels Used On DX Nets As A Signal Report 5X5 
NiMH Nickel Metal Hydride, Generally Refers To A Newer Type Of Rechargeable Battery 
NODE A Remotely Controlled TNC/Digipeatered As A Connect Point In Packet Radio. 
NPN A Type Of Transistor That Has A Layer Of P-Type Semiconductor Material Sandwiched Between Layers Of N-Type
semiconductor material. 
NTS National Traffic System Amateur Radio Relay System For Passing Messages. 
NTSC National Television System Committee (Not National Television Standards Committee) And Others Tv Standards. 
  
O (Oscar) 
OC Oceania 
odd split Unconventional Frequency Separation Between Input And Output Frequencies. 
offset (Repeater Term) In Order To Listen And Transmit At The Same Time, Repeaters Use Two Different Frequencies. On The 2 Meter Ham Band These Frequencies Are 600 Kilocycles/Second (Or 600 Kilohertz) Apart. As A General Rule, If The Output Frequency (Transmit) Of The Repeater Is Below 147 MHz Then The Input Frequency (Listening) Is 600 Kilohertz Lower. This Is Referred To As A Negative Offset. If The Output Is Above 147 MHz Then The Input Is 600 Kilohertz Above. This Is Referred To As A Positive Offset. 
Ohm The Fundamental Unit Of Resistance. One Ohm Is The Resistance Offered When A Potential Of One Volt Results In A Current Of One Ampere. 
old man (OM) Friendship Term, Friend, Pal Or Buddy 
OM (See Old Man) 
OO Official Observer Volunteer Who Monitors The Amateur Bands For Infractions 
open repeater (Repeater Term) A Repeater Whose Access Is Not Limited. 
OSCAR Orbiting Satellite Carrying Amateur Radio. 
oscillate Vibrate, Generate An Ac Or Other Periodic Signal 
oscilloscope An Electronic Test Instrument Used To Observe Wave Forms And Voltages On A Cathode-Ray Tube. Displays Time On The X-Axis And Amplitude On The Y-Axis, Z-Axis Is Intensity Of The Crt Spot. 
OT Old Timer Around Ham Radio For A Long Time 
OTC Old Timer's Club 
OTS Official Traffic Station 
output frequency (Repeater Term) The Frequency Of The Repeater's Transmitter (And Your Transceiver's Receiver). 
over Used During A Two Way Communication Under Difficult Copy Alert The Other Station That You Are Returning The Communication Back To Them. Other Terms Are Cambio (Change), Microphone To You, And In CW The Letter K Is Used As An Invitation To Transmit. Not Necessary On 2 Meter Fm Repeaters, As The Courtesy Beep Serves This Function. 
  
P (Papa) 
P-P Peak-To-Peak; As In Peak-To-Peak Voltage 
PA Power Amplifier 
packet radio A System Of Digital Communication Whereby Information Is Transmitted In Short Bursts. The Bursts ("Packets") Also Contain Callsign, Addressing And Error Detection Information. 
paddle Morse Code Key 
PAL Phase Alteration Line. Television Standard Used In Parts Of Europe. 
parallel circuit An Electrical Circuit In Which The Electrons Follow Thru More Than One Path In Going From The Negative Supply Terminal To The Positive Terminal. 
parallel-conductor feed line Feed Line Constructed Of Two Wires Held At A Constant Distance Apart; Either Incased In Plastic Or Constructed With Insulating Spacers Placed At Intervals Along The Line.
parasitic beam antenna Another Name For The Beam Antenna.
parasitic element Part Of A Directive Antenna That Derives Energy From Mutual Coupling With The Driven Element. Parasitic Elements Are Not Connected Directly To The Feed Line. 
parasitic Oscillations In A Transmitter On Frequencies Other Than The Desired One; These Can Produce Spurious Signals From The Transmitter. 
path noise (Repeater Term) A Term Used In Repeaters To Indicate That The Signal Is So Weak That The Limiters Have Not Engaged Thus Noise On The Signal Will Be Heard - This Is Referred To As Path Noise And Sometimes As (Incorrectly) White Noise (See Same) 
PBBS Packet Bulletin Board System 
PC Printed Circuit 
PCM Pulse Code Modulation Based On The Shannon's Communication Theory Or "Information Theory" That Describes His "Sampling Theorem" 
PEP Peak Envelope Power -  The Average Power Of A Signal At Its Largest Amplitude Peak.
peak-inverse-voltage (PIV) The Maximum Voltage A Diode Can Withstand When It Is Reverse Biased (Not Conducting). 
personal First Name  In "The Personal Here Is Bob" - CB Jargon That Has Crept Into Ham Jargon Old Timers Shutter 
phase The Time Interval Between One Event And Another In A Regularly Recurring Cycle.
phase modulation Varying The Phase Of An RF Carrier In Response To The Instantaneous Changes In An Audio Signal. 
phone Voice Modulation.
phone patch A Connection Between A Two-Way Radio Unit And The Public Telephone System. 
picket fencing (Repeater Term) A Condition Experienced On VHF And Above Where A Signal Rapidly Fluctuates In Amplitude Causing A Sound Akin To Rubbing A Stick On A Picket Fence. If A Repeater User's Signal Isn't Strong Enough To Maintain Solid Access To The Machine's Input (Such As When Operating From A Vehicle Passing Beneath Underpasses Or Through Hilly Terrain), The Signal Would Be Hard To Copy Because Of A Pronounced, Rapid Fluttery Or Choppy Characteristic.
pico The Metric Prefix For 10^-12, Or Divide By 1,000,000,000,000. 
PIN Positive-Intrinsic-Negative (Transistor Or Diode) 
pirate Station Using An Existing Callsign And Illegally Operating On The Air 
PL (Repeater Term) Private Line (Same As CTCSS)-- Low Frequency Audio Tones Used To Alert Or Control Receiving Stations. Pl, An Acronym For Private Line, Is Motorola's Proprietary Name For A Communications Industry Signaling Scheme Call The Continuous Tone Coded Squelch System, Or CTCSS. It Is Used  To Prevent A Repeater From Responding To Unwanted Signals Or Interference. Tone Is An Electronic  Means Of Allowing A Repeater To Respond Only To Stations That Encode Or Send The Proper Tone. Any Station May Be Set Up To Transmit This Unique Low Frequency Tone That Allows The Repeater To Operate. Also Used During The Autopatch Mode..
PLL Phase-Lock Loop 
PM Phase Modulation, Similar To Frequency Modulation.
P.M. Post Meridian (After Noon). 
PNP A Type Of Transistor That Has A Layer Of N-Type Semiconductor Sandwiched Between Layers Of P-Type Semiconductor Material. 
pole-pig Another Name For A Step Down Transformer Used By Power Transmission Companies. Some Surplus Units Can Be Reverse Wired And Used As The Transformers In A Ham Radio High Voltage Supplies.  
portable A Mobile Is A Amateur Radio Station Installed In A Vehicle mobile Station Can Be Used While In Motion. A Portable Station Is One That Is Designed To Be Easily Moved From Place To Place But Can Only Be Used While Stopped. Portable Operation Is Away From The Home Base Station.  
positive offset (Repeater Term) The Repeater Input Frequency Is Higher Than The Output Frequency. 
pot Potentiometer Continuously Variable Resistor Often Used For Adjusting Levels, As In Volume Control. 
PRB Private Radio Bureau, Administers Amateur Services 
product detector A Receiver Circuit Consisting Of A Beat Frequency Oscillator And Additional Circuitry For Enhanced Reception Of Ssb Signals. 
PROM Programmable Read-Only Memory 
propagation The Means Or Path By Which A Radio Signal Travels From A Transmitting Station To A Receiving Station.
PSK31 A Digital Transmission Mode - Phase Shift Keying With 31.25 Baud Rate .
PTO Permeability Tuned Oscillator 
PTT Push To Talk, The Switch In A Transmitter Circuit That Activates The Microphone And Transmission Circuitry 
pull the plug Shut Down The Station 
  
Q (Quebec)
Q A Figure Of Merit For Tuned Circuits. For Antennas, The Q Is Inversely Proportional To Useable Bandwidth, With Reasonable Swr. 
quad A Directional Antenna Consisting Of Two One-Wavelength "Squares" Of Wire Placed A Quarter-Wavelength Apart. 
Q-signals A Set Of Three-Letter Codes Which Are Used By Amateurs As Abbreviations. Commonly Used On Both Cw And Phone.
QCWA Quarter Century Wireless Association - Requires 25 Years Of Amateur Service For Membership. 
QRP Low Power Operation, Usually 5 Watts Output Or 10 Watts Input Power.
QSL To Acknowledge Receipt. Commonly Used To Indicate "I Understand", "I Coped Your Transmission (Or Report) All Ok". Also Used As A Term For Sending Cards By Mail To Confirm A Two Way Contact With A Station, Such As Qsl Via The Bureau. (See Burro Or Bureau). 
QSL Manager A Person, Usually An Amateur Radio Operator, Who Manages The Receiving And Sending Of Qsl Cards For A Managed Station). A Qsl Manager Is Needed Because The Managed Station Either Has Difficulty Handling The Volume Of Incoming Qsl Cards, Or The Station Is Geographically Located Such That It Is Difficult Or Impossible For That Station To Accept And/Or Send Qsl Cards. It Is Very Common For "Rare" Dx Stations And Dxpeditions To Have A Qsl Manager.  
QSO Two Way Conversation 
Quagi An Antenna Constructed With Both Quad And Yagi Elements 
  
R (Romeo) 
RADAR Radio Detection And Ranging. 
RAC Radio Amateurs Of Canada, A National Amateur Radio Organization In Canada.
RACES Radio Amateur Civil Emergency Service.
radio check Query From A Station Desiring A Report On His Stations Signal Strength And  Audio Quality
ragchewing Chatting Informally Via Radio 
RAM Random Access Memory 
R/C Radio-Control 
RCC Rag Chewers Club 
rcvr Receiver 
RDF Radio Direction Finding 
reactance The Opposition To Current That A Capacitor Or Inductor Creates In An Ac Circuit.
reflector An Element Behind The Driven Element In An Yagi And Some Other Directional Antennas.
refract To Bend. Electromagnetic Energy Is Refracted When It Passes Through A Boundary Between Different Types Of Material Much As Light Is Refracted As It Travels From Air Into Water Or From Water Into Air. 
repeater A Repeater Is A Receiver/Transmitter That Listens For Your Transmission And Re-Transmits It. Repeaters Usually Enjoy The Advantage Of Height And Power To Extend The Range Of Your Transmission. Repeaters Listen On One Frequency And Transmit On Another. The Separation Between These Two Frequencies Is Referred To As The Offset. See Repeater Operation 
repeater directory An Annual Arrl Publication That Lists Repeaters In The Us, Canada And Other Areas. See Arrl Repeater Directory 
resonance A Condition Where Xc = Xl, Establishing A Resonant Circuited For Selectivity (Parallel Circuit) Or A Maximum Impedance Circuit (Series) 
reset Applies To When A Repeater Timer Is Reset Back To Zero And Normally Occurs When The Carrier Of The Transmitter Drops.  
Rettysnitch A Fictional Torture Device For Bad Hams.  See Rettysnitch 
RF Radio Frequency, Emissions In The Radio Portion Of The Electromagnetic Spectrum 
RFI Radio Frequency Interference 
RG As In Rg-8 Coax - Rg = (1) Radio Guide Or (2) Radio Group As Opposed To Electrical Group Or Telephone Group 
rice box Equipment Made In Japan Or The Orient 
rig A Radio (Transmitter, Receiver, Or Transceiver) 
RIT Receiver Incremental Tuning. Also Known As A Clarifier 
RMS Root Mean Square 
roger I Understand and received 100% In CW "R"
roger beep A Dit-Dah-Dit Sent At The End Of A Transmission 
ROM Read-Only Memory 
rotor (See "Rotator") 
rotator A Device Attached To An Antenna Mast Which Rotates It So That The Antenna Can Point In Different Directions. Years Ago This Device Was Simply Called A "Rotor" 
Rover A Station That Operates From Several Grid Squares Or Counties During A Contest  
RS-232 Computer Interface Standard Set By The Electronics Industries Association (Eia). 
RST Readability, Signal, And Tone, A Three-Digit Report Indicating How Well An Operator'S Emissions Are Being Received.
RTMA Radio Television Manufacturers Association. 
RTTY Radio Teletype form Of Digital Communications. 
rubber duck A Shortened Flexible Antenna Used With Hand-Held Scanners And Transceivers. 
RX Receiver, Receive 
  
S (Sierra) 
SAREX Shuttle Amateur Radio Experiment, Communicating With Astronauts In Space. See Sarex 
SASE Self-Addressed, Stamped Envelope 
SEC Section Emergency Coordinator 
SECAM Séquentiel Couleur Avec Mémoire (French Color TV Standard) 
selectivity Ability Of A Receiver To Reject Signals Adjacent To Tuned Signal. 
sensitivity A Receivers Ability To Receive Weak Signals. 
separation or split The Difference (In KHz) Between A Repeater's Transmitter And Receiver Frequencies. Repeaters That Use Unusual Separations, Such As 1 Mhz On 2 M, Are Sometimes Said To Have "Oddball Splits." 
series circuit An Electrical Circuit In Which All The Electrons Must Flow Through Every Part Of The Circuit. There Is Only One Path For The Electrons To Flow. 
SFI Solar Flux Index
shack Ham Station Operating Area 
SHF Super High Frequency 3 GHz 
short path In Degrees Direct Great Signal Bearing Path Between Two Locations. Long Path Is The Reciprocal Bearing. 
signal A Radio Emission 
silent key A Deceased Amateur Operator 
simplex A Communications Mode In Which A Radio Transmits And Receives On The Same Frequency 
SINAD Signal To Noise And Distortion Ratio 
single-pole, double-throw (SPDT) switch  A Switch That Connects One Center Contact To One Of Two Other Contacts.
single-pole, single-throw (SPST) switch  A Switch That Only Connects One Center Contact To Another Contact. 
SINPO A Reporting System Used By Radio Hobbyists To Indicate How Well A Station Was Received strength, I=Interference, N=Noise, P=Propagation, O=Overall 
SITOR-A Simplex Teleprinting Over Radio System, Mode A 
SITOR-B Simplex Teleprinting Over Radio System, Mode B (FEC Mode) 
SK Silent Key, An Amateur Term For Indicating That A Ham Has Passed Away. Also One Of The Prosigns - Meaning "End Of Contact", See Prosigns
skip zone Dead Zone, Too Far For Ground Wave Propagation And Too Near For Sky Wave Propagation 
skyhook Antenna 
sky wave propagation The Transmitting Of Radio Waves Which Reflect Off Of The Ionosphere.
slim Someone Pretending To Be A DX Station, Usually Rare, That Is Supposed To Be On The Air. For Example, Someone In Southern Argentina Pretending To Be On Heard Island 
slop jar An Electrolytic Rectifier Rectifiers Were Common In The Late '20S And Early  30S. One "Cell" Consisted Of Two Strips Of Dissimilar Metals In A Caustic Potash (Lye) Solution. Many Cells Were Needed For A High Voltage Supply.  
SM Section Manager 
S-Meter Signal Strength Meter
S/N Signal-To-Noise Ratio 
spark gap An Early Transmitter Design Which Used Electrical Sparks To Generate Radio Frequency Oscillations 
spectrum The Electromagnetic Spectrum Or Some Portion Of It 
speech processor A Circuit That Increases The Average Level Of The Modulating Signal Applied To A Transmitter. 
splatter A Type Of Interference To Stations On Nearby Frequencies. Splatter Occurs When A Transmitter Is Overmodulated. 
split or separation (Repeater Term) The Difference (In KHz) Between A Repeater's Transmitter And Receiver Frequencies. Repeaters That Use Unusual Separations, Such As 1 Mhz On 2 M, Are Sometimes Said To Have "Oddball Splits."   
split Dx Stations Often Operate Split - That Is Transmitting On One Frequency And Listening At A Different Frequency Or Range Of Frequencies. This Avoids Congestion On The Dx Transmit Frequency. 
sporadic-E Random Patches Of Intense Ionization That Form In The E-Layer Of The Ionosphere And Refract Higher Frequency Signals That Normally Cannot Be Refracted By The Ionosphere. 
SPST Single Pole Single Throw (Switch) 
spurs Spurious Signals desired Signals And Frequencies In The Output Of A Transmitter. 
SQL Squelch circuit That Mutes The Receiver When No Signal Is Present, Thereby Eliminating Band Noise 
squelch tail (Repeater Term) A Brief Bit Of Noise Heard Between The End Of A Radio Transmission And The Reactivation Of The Receiver's Squelch Circuit. 
SSB Single Side Band
SSBSC Single Side Band Suppressed Carrier. 
SSN Sunspot Number
SSTV Slow Scan Television 
straight key A Non-Electronic Morse Code Key With One Paddle 
stub A Transmission Line 'Stub' Is A Length Of Transmission Line That Is Open Or Shorted At One End. It Is Effectively A Capacitor Or Inductor, Depending On Length, And Can Be Used To Achieve A Match [Vswr = 1:1] If Connected At A Selected Point In The Basic Transmission Line. 
superheterodyne A Radio Receiver Scheme Which Beats Or Heterodynes A Second Radio Frequency To The Incoming Radio Signals. The Combined Frequencies Form An Intermediate (If) Third Frequency. Aids In Selectivity Characteristics. 
SW Short Wave 
SWL Short Wave Listening
SWR Standing Wave Ratio, A Measure Of How Much Radio Energy Sent Into An Antenna System Is Being Reflected Back To The Transmitter. See Swr 
SWR meter A Device Used To Determine The Standing Wave Ratio Of An Antenna System 
synch. detection Synchronous Detection Is An Ingenious Method Of Processing An Am Signal To Improve Audio Quality And Reduce Interference From Adjacent Stations. 
  
T (Tango) 
TCXO Temperature-Compensated Crystal Oscillator. 
telegraphy The Transmission Of Information In Morse Code Format
telephony The Transmission Of Information In Voice Format
third-party communications Messages Passed From One Amateur To Another On Behalf Of A Third Person.
third-party communications agreement An Official Understanding Between The United States And Another Country That Allows Amateurs In Both Countries To Participate In Third-Party Communications. See 3Rd Party Agreements 
TI Talk-In Frequency 
ticket Slang For An Amateur Radio License 
timer Repeaters Often Incorporate A Timer Or Transmit Time Limiter To Control  The Length Of A Single Transmission From A User. The Time Limit Is Set By The Repeater Owner. 
time-out Excessively Long Transmission On A Repeater Causing The Repeater's Timer Circuit To Stop Further Transmissions
tone pad An Array Of 12 Or 16 Numbered Keys That Generate The Standard Telephone Dual Tone Multifrequency (DTMF) Dialing Signals. Resembles A Standard Telephone Keypad. (See Autopatch) 
TOR Telex Over Radio. 
TNC Terminal Node Controller, A Device Which Interfaces A Computer To A Transceiver And Performs A Function Similar To A Modem 
TNC Threaded Niell-Concelman (Standard Connector Type Used On Coax Cable, Named For Its Inventors). 
top band  160 Meter Ham Band (Highest Number Meter Band) 
TP Test Point 
traffic A Message Or Messages Sent By Radio 
transceiver A Radio That Both Transmits And Receives 
triplexer See Diplexer. 
tropospheric ducting Propagation Of Signals Above 30 MHz Via Bending And Ducting Along Weather Fronts In The Lowest Layer Of The Earth's Atmosphere, The Troposphere. 
TRX Transceiver 
TTL Transistor-Transistor Logic 
TV Television 
TVI Television Interference 
twisted pair Ham Slang For Telephone Or Telephone Lines 
two-tone test A Method Of Testing A Side-Band Transmitter By Feeding Two Audio Tones Into The Microphone Input Of The Transmitter And Observing The Output On An Oscilloscope. 
TX Transmit, Transmitter 
  
U (Uniform) 
UHF Ultra High Frequency 30000 MHz 
Uncle Charlie The FCC
unun Unbalance-balance, A Device Which Couples An Unbalanced Antenna Of One Impedance To An Unbalanced Feed Line Of Another Impedance 
uplink