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GLOSSARY

HAM TERMS

This is glossary contains general definitions of typical terms. Not all of the defini- tion listed may apply to your specific model of radio. Consult the manufacture for further clarifi- cation of model-specific terms. A

ACC (ACCessory) matching When the antenna’s impedance at resonance is at Adaptive filter optimum performance for your output cir- Digital filter associated with Process- cuit. ing. Antenna Adjacent-channel interference Device used to match an antenna to the output im- When a receiver is tuned to a specific and pedance of a transmitter. interference is received on a nearby frequency. APC (Automatic Power Control) AF (Audio Frequency) Current limiting of power to prevent dam- to finals in high SWR conditions. AFC (Automatic Frequency Control) Automatically compensate frequency drift. APRS (Automatic Position Reporting System) In conjunction with a GPS and TNC provide position AFSK reporting. Audio Frequency Shift Keying, a form of digital sig- nalling. ARES (Amateur Radio Emergency Service) ARES is a public-service organization of the ARRL. AGC () Automatically optimize receiver amplifier gain. ARRL (The American Radio ) The National Association for Amateur Radio in the ALC (Automatic Level Control) US. Limits RF drive level to power amplifier during trans- mit to prevent distortion. ASCII (American National Standard Code for Informa- tion Interchange) AM (Amplitude ) A seven-unit digital code for the transmission of tel- Amplifier eprinter data. A device used to increase the output power of a de- ATT (ATTenuator) vice. A network designed to reduce the amplitude of a sig- AMSAT (AMateur SATellite) nal.

AMTOR (AMateur Teleprinting Over Radio) ATV (Amateur ) A form of RTTY, radio teletype. FSTV, SSTV

Anderson power poles Auto patch Used by many emergency radio operators to con- Used in operation for intercon- nect 12 volts DC to their . nect.

ANF (Automatic Notch Filter) Average power Power measured on standard power meter. ANL (Automatic Limiter) Eliminates impulse and static noise peaks.

ANT (ANTenna)

Antenna system Term used for a RF reference potential for some types of antennas. Most unbalanced or asymmetrical antennas need a good RF ground.

Antenna impedance The impedance of an antenna at its resonance. Al- though an antenna’s impedance fluctuates with the frequency of operation, an antenna should be 50 Ω for most .

1 B

Backscatter A Radio signals reflected back from ionized patches in the . B Backstay C Rigging to support the mast in maritime mobile in- stallations, usually insulated for HF antenna pur- D poses.

Balun E A simple transformer used to change an unbalanced input to a balanced output. F Band G A range of .

Bandwidth H Frequency needed for particular type of emission. I Bank Memory bank J BCI (BroadCast Interference) K Ham radio signals used for propagation study, found L on specific frequencies.

BFO (Beat Frequency Oscillator) M

BNC (Bayonet Neill-Concelman) N A type of antenna connector. O BPF (BandPass Filter)

Bunny hunt P Finding hidden , sometimes called “T HUNTING” and “Fox Hunting.” Q Busy lockout R Inhibits transmit on a frequency in use. S T U V W X Y Z

2 C

Call sign CTCSS (Continuous Tone Coded System) Sequence of letter and numbers used to identify Adds a continuous sub-audible tone amateur radio operators and issued by the to the transmitted carrier. Receivers set for the same licensing bureau. low frequency tone can decode signal to hear the audio. CAP (Civil Air Patrol) Volunteer affiliate of the Air Force. CW 1) Capture effect 2) ClockWise Only the strongest signal heard over an FM re- ceiver. CW filter Used to narrow the IF passband to improve recep- Carrier tion selectivity in crowded band conditions. An unmodulated transmitted signal.

Carrier frequency offset (=Carrier Shift) Distance between mark and of the carrier for RTTY or similar communications.

CBR (Cross Band Repeater) A repeater which receive incoming signal and re- transmit it in different bands— e.g. receives 144 MHz bands and re-transmits 430(440) MHz bands.

CCW (Counter ClockWise)

CH (CHannel) Sequence of memory positions where frequency and related information is stored.

CI-V Icom Control Interface allows multiple radio control simultaneously.

Clipping Overdriving an amplifier circuit, causing the signal to drop out on voice peaks. (AKA: Flat topping a sig- nal)

Contesting Working as many stations as you can over a specific amount of .

Conversion Number of IF circuits in the receiver.

Coronal hole Sunspot activity that may lead to enhanced VHF and 10 meter propagation.

CPU (Central Processing Unit)

CQ Radio communications term used to call others.

Crossband repeat A mode in many dual band radios where a radio transmits on one band, a crossband repeater trans- mits the received signal on another band, which is heard back by the radio on the other band. 3 D

D-RATS Doppler shift A Multi-platform integrated tool for communicating Common in satellite communications, where signals digital information, developed for First Responders, may very up or down in frequency, as the satellite B using D- radios. approaches and departs from view. C D-STAR Downconverter Digital Smart Technologies for Amateur Radio, an A device to take higher frequencies, and lower them D open protocol. to appear at a lower frequency, for reception.

Data communications Downlink (↔Uplink) E Transfer of data between two or more locations. Frequency that repeater or satellite transmits on to a user. F dBd Unit of RF power as compared to an ideal half wave DSP (Digital Signal Processor) G . Used to improve the signal to noise ratio for clearer and more legible communications. Relatively new to H dBi the ham radio. Unit of RF power as compared to an isotropic an- tenna. DTCS (Digital Tone Coded Squelch) I A Selective call system. dBm J measure, 1 mW with a load impedance of DTMF (Dual Tone Multi-Frequency (=touch-tone)) 600 Ω (0 dBm=1 mW). Used for transmit/receive numeric information such K as phone number, PIN, remote radio control com- DC (Direct Current) mands, etc. L DC ground Dualwatch A connection point directly to chassis or battery Receiving two signals simultaneously. M ground to prevent build-up of hazardous DC volt- ages. N A non radiating 50 Ω load connected to the transmit- DCS ter to replace the antenna for testing purposes. Digital Coded Squelch, a method of silencing radios O until a specific string of tones are received to open Duplex the audio stage. An alternate to CTCSS. An operation mode in which the transmit and receive P frequencies are different. Deviation Q A measurement for an FM signal for the maximum Duplexer frequency changes on either side of the carrier fre- A device which divides transmit and receive sig- R quency. nals.

Digital communications Duty cycle S Information sent digitally, which may be decoded as The ratios of transmit to receive time. voice, data, and/or . T Dx’pedition Dipole Trip to foreign land or rare entity to operate ham TU A half wave antenna, with a bi-directional radiation radio. pattern. V Distress call Signals a life-threatening situation. Most commonly W referred to as an SOS or call. X Distress frequency A frequency or channel specific for use in distress Y calling. distress frequencies are 2.182 MHz and 156.8 MHz. Survival craft use 243 MHz. Maritime distress frequencies are the same, Z while general aviation frequencies are 121.5 MHz.

4 E F

E LAYER The ionospheric layer usually responsible for most Found on 440 MHz and 1.2 GHz antenna circuits. 10 meter and 6 meter over 1500 mile paths. Appears especially in summer season. Fading Signal reduction due to atmospherics. EBS (Emergency Broadcast System) A system where at first an attention tone is trans- Feed point mitted over all station ad the tone followed Where the cable or ladder line joins the ac- with specific instruction regarding the receivable fre- tive antenna. quency in the national emergency. Filter EEPROM (Electrically Erasable and Programmable A circuit designed to pass only the desired Read Only Memory) frequency(s).

EME FM Earth Moon Earth, also known as moon bounce, is a 1) radio technique where amateur radio operators op- 2) FM broadcast erate via reflected signals from the Moon. Making a Foldback signal path from an earth bound station, reflected off A circuit to limit power output when the transmitter the moon, back to another earth bound station. senses elevated SWR or temperatures.

EMI FSK (Frequency Shift Keying) Electromagnetic Interference, sometimes caused by battery chargers and inverters. FSTV (Fast Scan TV) Graphics (and audio) communication using TV Emission broadcast signals, requires a wide . Transmission of a signal Full duplex An operation mode, which transmits and receives on different frequencies at the same time, as a tel- ephone communication.

Fuse An intentional weak link to guard against overload.

5 G H

GaAs FET Ham A Sensitive transistor, found in VHF/UHF receiver am- A licensed radio operator who enjoys the hobby and plifiers, with a low noise floor. service of radio communications. B Harmonic C A type of Omni-directional antenna. Multiple of a fundamental frequency.

Ground Wave Heat sink D Electrical wave directly travelling from transmitter. The heavy fins on the back of a transmitter to dis- sipate heat buildup. E Grounding Electrical connection to the earth. HF () F 3–30 MHz range signals. (Normally, 1.9 MHz band also included.) G HPF (High Pass Filter) H Hz (Hertz) I J K L M N O P Q R S T TU V W X Y Z

6 I J

IC JT65 Integrated Circuit, found in large scale chips within A weak signal digital mode, primarily used on HF a radio. and 6 m, for weak signal and EME type contacts (moon bounce, meteor scatter). IF (Intermediate Frequency) Internally converted frequency for amplification and other signal processing.

IF shift A function that electronically shifts the IF frequency from a center frequency to reduce interference.

IMD (Inter-Modulation Distortion) Distortion within RF circuits made with upper and lower adjacent channel signals.

Inverter An electrical device that converts direct current, DC, to alternating current, AC. Can be a source of noise on HF bands.

IRLP Radio Linking Project, allowing ham opera- tors to join in on a party line, with the internet con- necting together.

7 K L

Knife edge LCD A The refraction of a signal over tall buildings and Liquid Crystal Display, primarily used for displaying mountains. frequency and radios operations. B LED C Light Emitting Diode, a low current low voltage com- ponent to illuminate a radio dial. D LF (Low Frequency) 30–300 kHz range signals. E Li-Ion (Lithium Ion) F Rechargeable battery which has better capacity than Ni-Cd, Ni-MH, etc., no memory effect after repeated non-full charge/discharge cycles. G

Logging software H A computer log of contacts, used for QSL card con- firmations on contacts. I LPF (Low Pass Filter) J LSB (Lower Side Band) K L M N O P Q R S T TU V W X Y Z

8 M N

Maritime mobile NB (Noise Blanker) Amateur radio operation from aboard a marine ves- A function reducing pulse-type noises. sel. NBFM (Narrow Band FM) MARS (Military Affiliate Radio Service) Ni-Cd (Nickel-Cadmium) Memory bank A set of memory channels organized into a group. Ni-MH (Nickel-Metal Hydride)

Memory effect Notch filter Rechargeable batteries such as Ni-Cd and Ni-MH Sharp and narrow rejection filter for elimination of types may be temporality getting less capacity as a interfering signals result of repeated non-full charge/discharge cycles. NR (Noise Reduction) It is called so since rechargeable batteries lose ca- DSP feature reduces unwanted signal noise pacity as if “memorize” wrong full capacity level at less than full charge. Li-Ion batteries are free from NVIS this effect. Near Vertical Incidence , a method of low- ering a dipole, or an angled vertical, to enhance a MF () high elevation of signal radiation and reception. 300 kHz–3 MHz range signals.

MIC (MICrophone)

Mobile In a vehicle, or other type station no fixed at a spe- cific location.

Modulation Method of adding information to a carrier.

MT63 A weak signal, digital communications mode, being used in MARS net traffic.

MUF Maximum Usable Frequency, the highest frequency that may return a skywave back to earth.

9 O P

Offset frequency PA (Power Amplifier) A Frequency difference between transmits and re- ceives. PACTOR B modulation used mostly on the HF Ohm bands for digital messaging. C Unit of resistance. Parawatch (=Dualwatch) Optoisolator D Found in tuning knob circuits, where an LED shines PBT (PassBand Tuning) through an interrupter to signal a data pulse. A function to reduce interference by electronically E narrowing the IF bandwidth. OSC (OSCillator) F PEP () Oscillator RF power at maximum amplitude. The heart of all radios, needing a small amount of G feedback to keep it oscillating. Photovoltaic Solar cell, converting photons to electricity. H PLL (Phase Locked Loop) I Circuit to synthesize the different frequencies a radio will operate on. J Pocket beep Beeping function when specific signal is received. K Power supply L Usually converts 110 Volts AC to 12 Volts DC. Sometimes built in, sometimes external to the equip- ment. M

Priority N Reception mode, which by a selected frequency is always periodically, checked when VFO is set to dif- O ferent frequency P PSK31 A type of radio-teletype using Phase Shift Keying with a very narrow bandwidth as an efficient way of Q communicating. R PTT (Push To Talk) S PWR (PoWeR) T TU V W X Y Z

10 Q R

Q Reflected power Response of a circuit over a specific bandwidth. Non-radiated power dissipated as heat when the Also, Ham Slang for a , or QSO. transmitter is mismatched to the antenna or load.

QRP Refraction Low power operation, usually 1 or less. Radio waves are bent back to earth, via the iono- sphere, by refraction.

Repeater Radio systems, which receive incoming signal and re-transmit it for extended communication area. Nor- mally put on geographically high locations for VHF/ UHF hand portables.

RF (Radio Frequency)

RF ground Connection of amateur equipment to earth ground to eliminate hazards from RF exposure and reduce RFI.

RFI (Radio Frequency Interference)

RIT (Receiver Incremental Tuning) Fine-tuning receive frequency without changing dis- played or memory frequency.

RTTY (Radio TeleTYpe)

RX (Receive)

11 S

S/N (Signal to Noise ratio) SWR (Standing Wave Ratio) A Measurement of forward vs. reflected power output SAR (Search And Rescue ) during transmit. B Safety RF exposure limits, set by ANSI (American National C Standards Institute), to minimize over exposure to RF signals from a nearby antenna. D Scan E Continually sweeping frequencies looking for sig- nals. F Scan Edge End and start frequencies for a scanning range. G Scratch Pad Memory Temporary frequency memories for quick access. H Semi Duplex I An operation mode in which transmits and receives is accomplished on different frequencies alterna- J tively.

Sensitivity K Indicates how weak a signal the receiver can de- tect. L Set mode M An operation mode used for radio. To set less fre- quently used control features. N Simplex An operation mode where transmit and receive fre- O quency is same. P Trained volunteer storm spotters for the National Q Weather Service.

SMA (Sub-Miniature a connector) R Type of antenna connector, used in VHF/UHF port- able. S SP (SPeaker) T Split An operating mode in which the transmit and receive TU frequency is different. V SQL (SQueLch) A function muting audio output for set conditions. W SSB (Single Side Band) X SSTV (Slow Scan TV) Graphics communication using narrow bandwidth. Y SWL (Short Wave Listener) Z

12 T U

TCXO (Temperature Compensated ) UHF () Heated crystal oscillator for better frequency stabil- 300 MHz–3 GHz range signals. ity. UHF connector TNC Sometimes called a PL-259 plug, for , 1) Terminal Controller on VHF. for . 2) A type of antenna connector. Uplink (↔Downlink) Frequency that user transmits to the repeater or sat- TOT (Time Out Timer) ellite. Time limiting function for continued repeater or other operations. USB 1) Upper Side Band Towers 2) Universal Serial Bus Antenna support structures. UTC ( Coordinated) An astronomical time based on the Greenwich me- A device similar to a downconverter, but used for ridian (zero degrees longitude). both receive and transmit.

TS (Tuning Step) Incremental steps

TSQL (Tone SQueLch) Squelch function using subaudible tones, selective call.

TVI (TeleVision Interference)

TWT Traveling Wave Tube, found in amplifier circuits.

TX (Transmit)

13 V W

VCO Waveguide A Voltage Controlled Oscillator, found in the PLL sec- The carrier of from radio to antenna, tion of the modern radio. and back. B VFO (Variable Frequency Oscillator) Weather Alert C An operation mode in which operator can change NOAA broadcast station transmitting alert signals. frequency freely. WFM (Wideband FM) D VHF () 30–300 MHz range signals. E VOX (Voice Operated transmission) F A function that automatically switches the transmitter to transmit when you talk into the microphone. G VSC 1) Voice Scan Control H 2) Voice Squelch Control I J K L M N O P Q R S T TU V W X Y Z

14 Y Z

Yagi Zener diode Directional antenna. A diode used to regulate the operating voltage.

15 Number/Others A B C D E Number/Others F G H I J K L M N O P Q R S T TU V W X Y Z

16 17 A B C D E F G H I J K L M N O P Q R S T TU V W X Y Z

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