The Shortwave Jargon Glossary An ongoing effort last updated 7/17/04 "I am often asked how radio works. Well, you see, wire telegraphy is like a very long cat. You yank his tail in New York and he meows in Los Angeles. Do you understand this? Now, radio is exactly the same, except that there is no cat." __Attributed to Albert Einstein Utility World covers the following: Utilities Numbers Oddities A "utility" is usually defined as something useful, a radio transmission intended to aid in someone's job or mission. A broadcast is not a utility, because it is entertainment or propaganda. Ham and CB are not utilities because they are hobbies, but when the hobbies are used in a disaster or other such situation, they become enough of a utility for me to write about. Numbers are a special case of utilities, kind of a gray area, because they are broadcasts, sometimes even posing as entertainment, but they are also message traffic, real or dummy or ?????????. It is suspected that the "numbers" are messages from intelligence agencies to spies in the field, though other theories vary from offshore fund transfers to fish prices. Oddities are everything else. They're whatever funny noises, beeps, musical tunes, or just stuff that can't be explained any other way. A few have been around for years, being weird and confusing people. Once in a great while, an oddity reveals itself, as when "The Buzzer" finally sent a real message, and was reclassified as a Russian numbers marker. Presumably, most other oddities have some purpose beyond giving short wave writers something to do. We sure don't know what is, though. Oddities aside, most of the funny noises you hear on your shortwave radio are various kinds of teleprinting. This used to be all RTTY, radioteletype, first on mechanical printers and then by computer, but now there are hundreds of other systems that do the same thing. Some are networks, like a radio version of the Internet, others store and forward messages, still others allow people sitting at keyboards to type directly to one another. It's getting harder to characterize all these different systems just by sound. Most of them are variations of frequency or phase shift keying. RTTY has a distinctive chatter you've already heard many times, but other schemes sound like steady buzzes, intermittent chirps, warbles, beeps, or just huge noises more reminiscent of the old, broad-spectrum jammers. A slightly similar, but usually more cyclical, noise is FAX, facsimile, a machine that scans a picture or a page of text and broadcasts it, one line at a time, for remote reproduction. It's like office fax, except that office fax is a newer system and uses digital encoding. HF fax is analog, an older system possibly dating back to Thomas Edison. HF fax uses huge, expensive, drum scanners with photomultiplier tubes that can handle an entire newspaper. Its two significant parameters are lines per minute, LPM, sometimes also called RPM, and "Index Of Cooperation," IOC, a number having to do with resolution of the fax, basically how large each line is. Do you REALLY want to know any more than that about the Index Of Cooperation, like the use of pi in its computation? Didn't think so. Most HF faxes these days are weather charts for small vessels at sea, and so they sound like a piercing shriek interrupted by a scratching as the black dots are transmitted. This scratch will change as the picture does. Coming up fast in the new century are all the digital modes, with their funny names and funnier sounds. All of these are different schemes for doing what computer modems do, but with the robustness and bandwidth conservation needed for use on HF. Most of these modes are keyboard-to- keyboard (PSK31, Hellschreiber), but some allow file transfers (Pactor, G-Tor). Others can be configured for encoded voice (ANDVT), and even more can do wide-area networking (Link-11). Several CDs are available that have the various sounds, with an identification of what they are. These are useful in sorting all the noises out. Frequency Ranges These are the most confusing acronyms in radio. I think the number 3 is used because the ranges were originally based on wavelength, where a meter/second is 1/300,000,000 the speed of light, and one meter is thus 300 MHz. The switch to frequency as a more efficient form of measurement led to the current decades of three we see here. ELF Extremely Low Frequency (3-300 **Hz**) This is mostly power systems, though the US military Project ELF uses it to communicate with submarines, at a data rate measured in minutes per word. Moving up, we get: SLF Super Low Frequency (300-3000 Hz) VLF Very Low Frequency (3-30 kHz). LF Low Frequency (30-300 kHz) "Long Wave," mostly beacons Utility World deals, roughly, with the range 300 kHz - 30 MHz: MF Medium Frequency (300 kHz-3 MHz) "Medium Wave" HF High Frequency (3-30 MHz) "Short Wave". And, in solar peaks, as in 2000-2001: VHF Very High Frequency (30-300 MHz). Notice that short waves are really about the longest waves in regular use for communication today, and that high frequency really isn't very much higher than anything, except AM broadcasting, navigation beacons, and some maritime Morse code. These names date from the era when HF was the new frontier. You'll hear the Romeo Mike (radioman) talk about going to Foxtrot Mike (FM, in other words, VHF), or sometimes Uniform, which is: UHF Ultra High Frequency (300-3000 MHz). Now, usually when the military says UHF, it means the range from approximately 240 to 400 MHz, which is used by military aircraft. Most of this is actually still in VHF, but they presumably needed to avoid confusion with the VHF air band, 108 - 138 MHz, used mostly by civilian aircraft. So be it. Moving on up, we get: SHF Super High Frequency (3-30 Ghz) aka microwave EHF Extremely High Frequency (30-300 Ghz). Above this we are in a transitional area to infrared light, and one being investigated by astronomers with some wild and wooly circuitry including superheterodynes that use lenses instead of wires and mixers. Even the Hubbell Space Telescope cannot photograph planets directly, but peaks in this range of RF/IR indicate the possible presence of same, making it far less likely that we are the only life in the universe. Modulation schemes Modulation is any change in a radio wave to encode information, whether, speech or data. Techniques are classified into amplitude, frequency, and angle (phase) modulation. CW: Continuous wave. Aka OOK "on-off keying." Morse code, Hellschreiber. Amplitude Modulation AM Oldest, aka "Ancient Modulation." Result of a mixing of audio and carrier wave, adding two sidebands (sum and difference frequencies, a technical result of the mixing process). Good audio fidelity for broadcasting, but prone to fading and noise, and inefficient for HF communication. SSB Single sideband Aka SSSC, single sideband suppressed carrier. As the name implies, uses filters or balanced mixers to put all the power into the information part of the signal, the sidebands containing the mixing frequencies. Carrier is not transmitted, and the remainder can be double sideband, upper sideband, or lower sideband. SSB sounds like Donald Duck until the missing carrier is restored in the receiver as part of the IF detection process. On HF, SSB still fades, but you don't hear it as much. It's also way more efficient. If the carrier is transmitted in a reduced form, as several "numbers" stations do for easier tuning, it is called R3E mode. Consult the wonderful ITU tables for further. Television Analog video is "vestigial sideband," a result of mixing the raster scan voltages with the carrier and filtering the result. TV is slowly converting to digital video, however. Frequency Modulation FM More recent modulation scheme, invented between the world wars by Major Armstrong for RCA, that varies the frequency of the carrier wave to encode speech or data. FM is less prone to noise, but it eats bandwidth, so you don't hear it a lot on HF. FM broadcasting was a chance to refine many of the parameters along with the modulation scheme, and so it sounds a lot better than the AM we are used to. Narrowband FM, where the carrier deviation from center frequency is limited, is very common for voice communication on VHF and UHF. Analog fax is FM, though usually fed to an SSB transmitter, giving it characteristics of both. FSK Frequency Shift Keying FM variation that uses two or more fixed audio frequencies. Actually, SSB can be made to sound the same with a process called AFSK (Audio Frequency Shift Keying), with the resulting signal being frequency-shifted. Good for encoding ones and zeroes, or for teleprinting codes. Angle Modulation PM Phase Modulation Descriptively named mode that retards the phase of a signal to encode information. In practice, sounds just like FM, though it's technically slightly different. Most of the FM used in two way radios is actually PM, but you didn't want to know that. PSK Phase Shift Keying Real popular in modems. Various combinations of FSK and PSK are used in modern teleprinting and data transfer. PSK31 is an example of the application of this mode to HF, using two closely-spaced tones that are rather dramatically phase- shifted by computer-driven circuits. International Radio Phonetics: These can confuse people coming from scanner listening, where a different alphabet is in use. The military and international civil aviation organizations both use: Alpha Bravo Charlie Delta Echo Foxtrot Golf Hotel India Juliet Kilo Lima (LEE-mah) Mike November Oscar Papa Quebec (kay-BECK) Romeo Sierra Tango Uniform Victor Whiskey X-ray Yankee Zulu. Time Measurement Radio scheduling and intercept times are typically kept in UTC, Co-ordinated Universal Time. UTC is kept by standard atomic clocks, not by observation of the Earth's position in space. It drifts out of sync with the astronomical universal time scales, UT0 through UT2. Since people want to know the right time of day as well as the most precise intervals, UTC is corrected in December (New Year's Eve) or June whenever the difference exceeds 0.7 seconds. These are the notorious "leap seconds" that are talked about in the news. UTC is not Greenwich Mean Time, an older time scale that was once a mean solar standard time that Great Britain kept for the rest of the world, but it's so close that if you insist on calling it GMT I won't get upset. I'll snicker to myself, but I won't get upset. I'm a nice guy. Neither is UTC is really the exact same thing as Zulu time, Z time, the time on the Z meridian, the prime meridian, the Greenwich Meridian as determined by the British when they were in a position to determine such things, either. Z is from a different system of nomenclature that assigns letters to every STANDARD time zone in the world. But, since I really don't see much of a difference, it's close enough for Utility World. The only thing that's really important is to get into the habit of using UTC, GMT, Z, or whatever you call it at your house, for all things radio, since otherwise signals are being heard all over the place and it's just too confusing to remember if it's Newfoundland or Nova Scotia that's off a half-hour (don't write me, I actually know it's NFD), or who's on summer time April 1 and who isn't, and all that. Now, remember that in the USA the evening hours are actually a day later in UTC. This leads to endless confusion, but that's just the way it is on a round planet. Radio Prosigns (PROcedural SIGNalS): People can talk and listen at the same time, sort of, but simplex radios can't. Prosigns bring order to chaos. It's actually possible to say, "Roger, Wilco, Over and Out," and mean something, though purists would say that "Over" means an invitation to transmit ("Over" to you), while "Out" means that the contact is completed, and not to transmit, as in, "I'm out of here." Therefore it would mean "I received, I will comply, time for you to transmit, don't transmit." These prosigns are like the ones taught in the U.S. military, and recommended for MARS and amateur use, plus they've always struck me as nice and logical: Break (1)Message delimiter (2)Short pause (3)I need to use the frequency/I need to talk. There's often a precedence for breaks, like "break" if you just want to shoot the breeze, "break break" if it's urgent, "break break break" for emergencies. This is a good idea, but people always seem to mess it up. Clear Means about the same thing as "out," but implies that the channel is now available, as on a VHF repeater or a police radio, where one side is still on the air. CQ Hello all stations. (You can say so on voice, but it sounds awfully weenie.) Usually means you're inviting anyone that hears you to call. Figures A number follows, said one digit at a time. Go Ahead Technically, an "invitation to transmit." This is a bit subtle. You say Go Ahead after a call or CQ where you don't know if anyone is going to talk. I spell A word follows, spelled in phonetics. Procedure is to say the word, say "I spell," spell in standard ICAO/ military phonetics, say the word again. MAYDAY This transmission is a distress call. This station has a life-threatening emergency. Out End of work/contact. Standing by. No reply expected. Over End of transmission - go ahead. Reply expected PAN PAN This transmission is urgent. Roger I have received your message. "10-4" is the police code for the same thing. "Roger 10-4" is redundant. SECURITE This transmission pertains to safety of navigation. Standby Listen. May mean that transmission is a priority grade, so everyone else should shut up. Wait Out Longer pause. I'll be back but I'm momentarily through transmitting, so don't reply. Wait A pause. I'm still transmitting. Don't talk. Wilco Will comply. I don't care what anyone says, Wilco is functional and I use it, corny or not. Damaged nuclear weapon codes (US): The movie got these completely wrong. They're radio brevity codes relating to the severity of potential radiation release, and the size of the resulting perimeter, if any. Broken arrow Nuclear weapon accident w/ damage; 2000 ft perimeter Bent spear Major nuclear weapon incident Dull sword Nuclear weapon exercise Faded giant Radiological incident at nuclear reactor No-lone zone Nuclear weapon area, cannot enter alone "I don't know what's worse: that this had to happen, or that they've already got a radio code for it." --------------"Broken Arrow" EEI Codes: EEI stands for "Essential Elements of Information," a standard report form used by U.S. federal and military stations to report incidents in a standard, non-hyped manner sadly lacking on broadcast news. BAD MAGIC Riot/civil unrest BLOCKED LANE Blocked interstate highway BRAZEN BRIMSTONE Volcano BROKEN TRACK Train wreck or derailment DARK DAY Power outage DARK WATER Oil spill DEEP SEA Shipwreck or incident FALLEN STAR Air Crash FAST WATER Dam breakage/damage HOT AIR Gas leak/explosion HOWLING WIND Hurricane/ typhoon MIGHTY WIND Other damaging wind storm LOST SUPPORT Bridge damaged/out LOUD BANG Bombing NUCLEAR GRAYSTONE Nuclear incident POISONED GROUND Chemical spill ROLLING THUNDER Earthquake SCORCHED EARTH Forest fire SECURE HAVEN Search & rescue TALL WATER Flood TSUNAMI Tsunami VIOLENT TWISTER Tornado WHITE BLANKET Major winter storm DV codes: DV means "Distinguished Visitor." You'll hear things like, "Inbound with DV2 plus 20." This means that the aircraft has 2 distinguished visitors and 20 other passengers. Secret service codes haven't been heard on HF in a while, and due to the current paranoia about national security they have been dropped from this document. Air Force 1 is any USAF aircraft with the president aboard. SAM means Special Air Mission. Only a few, mostly Presidential and Vice-Presidential planes or backups, have standing callsigns. The rest, such as State Department, will use mission or tail numbers. Executive 1 is any civilian aircraft with POTUS aboard. You'll hear "Executive One Foxtrot." The F is for family, any flight with a first family member aboard. SAM 01 is a visiting head of state. The Vice President is Air Force or Executive 2, and Executive 2 Foxtrot is the family. SPAR, Special Air Resources, + numbers is also a standing callsign for a VIP aircraft. These carry Senators and similar. Marine One is the Presidential chopper when POTUS is aboard. Other fun things: 73- From old telegrapher-speak for "best regards." 88- Like 73, but means "love and kisses." ACSB Amplitude Compandored Sideband, a communication system using a single sideband with a pilot tone, allowing an expander in the receiver to restore the amplitude that was severely compressed by the transmitter. (Note that most of the noise reduction circuits used in audio recording are also variations of companding.) This mode promised greater robustness and fade-resistance on HF than even SSB, but was pretty much leapfrogged in favor of spread spectrum, which solves the problem even better. A Index- Briefly, a number which increases as movement in the Earth's magnetic field over the previous 24 hours does. Ap, the planetary A index, is a good indicator of aurora. For short wave communication, lower numbers are better. Stations become harder to hear when the A index exceeds 30-35, which is considered a major disturbance. Alexanderson Alternator- A hot-rod AC generator, sometimes the size of a big truck, that is spun up to high RPM. It makes up to 200 kW of RF that can be used to communicate on low frequencies. In the Bad Old Days, when high-power spark transmitters banged and caught fire and generally acted badly, General Electric sold a lot of these alternators as a viable alternative. Marconi was about to convert when vacuum tubes made both systems hopelessly obsolete. Now, obviously, these alternators have to be keyed in the output circuit to make Morse code. We are talking about switching a 200-kW RF circuit, perhaps many times a second. It isn't real pretty. The real fun, though, comes when Alexanderson alternators are used for AM voice communications. Remember that class A or B modulators haven't been invented yet. Several modulation schemes exist, all of them doing things that make old Frankenstein movies look tame. There are still a couple of these old devices, with their acres of antennas, around to be fired up for special occasions. They are NOT for the faint of heart! Alligator- Link-11 (from sound made by rutting gator) AM- Amplitude modulation. The first, and simplest, means of transmitting voice over radio, by varying the strength of the carrier wave to match the modulating sound. Detection is by simple rectification, which gets you back the sound. Dental fillings are real good for this. ANDVT- Advanced Narrowband Digital Voice Terminal. Currently a very popular, digital encryption scheme used for secure military communications. When US military or Coast Guard "go green," usually ANDVT is what's heard next. There's a sync beep or two, then a digital hiss, from a special radio modem. Recently, this same modem has been used for automated data bursts at regular intervals. Atencion- Any of several very powerful "numbers" transmissions that begin, usually on the hour, with the Spanish "Atencion" ("Attention!"), then groups of 5 digits in Spanish, ending "Final, Final," usually after around 45 minutes. They are strongly suspected to come from Cuba. Aurora- Any of several flows of charged particles along the earth's magnetic field, converging in auroral ovals on the night sides of the sub-polar latitudes. Solar activity can increase these flows, causing the northern and southern lights. On HF, the effect of aurora on a radio path is as if the sound had been processed through a musician's phase-shifter, with wobbly pitch and time distortions. These effects grow worse, and more widespread, as aurora increases in a disturbance. On VHF, aurora can actually return signals, causing freak propagation. The geomagnetic "A" and "K" indices broadcast on WWV are taken at latitudes where they are something of an auroral indicator. Backscatter- The path taken by a signal that is returned by the ionosphere (skywave or skip), but which is reflected back from the ground, to the ionosphere, into what would otherwise be a dead zone under the skywave hop (the "skip zone"). Backscatter sounds weak and wobbly, and it's easy to confuse with the effect of aurora. However, the paths involved differ greatly. Beacon- A transmitter, which broadcasts a steady signal, or an identification in Morse code, or both. Locator beacons usually use low frequencies below AM broadcasting, and are intended for navigation with radio direction finders or (more recently) differential GPS. They can also track the locations of drift nets (illegal but still used), oil drilling rigs, animals, vehicles, or anything else Propagation beacons, most popular in amateur radio bands, are automated stations at known locations, usually with fairly low power, that let distant listeners know when the bands are open. Rescue beacons are activated in emergencies, for radiolocation by satellites or terrestrial rescue agencies. These more typically use VHF and UHF. Block time- Time that an aircraft is "in the blocks" (the wheel chocks that keep it from rolling) and thus safe to unboard. The real arrival time of the plane. Boatanchor- An old radio using tubes, typically enormous, built like a battleship, and restored to pretty respectable performance even by today's standards. They light up and buzz, and are generally lots of fun. BLUE STAR Radio callsign of a US Navy aircraft operations support net controlled from an unknown location. The former location, at the Roosevelt Roads Naval Weapons Training Center, PR, is closed. BRAVO ZULU US military, especially Navy, slang for "Good job." Comes from a standard brevity code in a signalman's manual. Cherry Ripe- A British numbers broadcast, named for the folk tune that starts it. Chirpsounder- Ionospheric sounder, usually military, that sweeps up HF on a regular schedule. The chirp is the noise heard, in CW or SSB mode, when it passes your frequency. Most ALE systems depend on regular chirpsoundings to optimize frequency selection. Coronal Hole- Just that, a hole in the sun's corona where particles might blow out at the Earth, disrupting shortwave communications. Coronal holes can last several months, and they appear most at the bottom of the "sunspot cycle" when HF isn't that great to begin with. The result is a disturbance every 27-28 days, when the hole rotates around the sun and back into position. Coronal Mass Ejection- The expulsion of charged, massive particles, usually protons, from the sun after a flare or other disturbance. If these protons reach the Earth, a magnetic storm results. CME is the major cause of aurora. Counter- The U.S. numbers transmission that starts by counting to ten in Spanish or English. Crystal- Not something you wear around your neck if you're into New Wave, but a smaller piece of the some stuff, usually quartz or Galena, incorporated into a radio circuit. Frequency crystals are used in all modern radios to generate waves used in tuning or transmitting with computerlike "synthesizers." Older radios used specially cut crystals, sometimes in warm metal boxes called "ovens," to determine the frequency when accuracy was desired over agility. Hence the term, "Rock bound," for a transmitter that could not change frequency rapidly, if at all. There's also a "crystal diode," a rectifier that uses a junction between two materials, one of them a crystal. Very early receivers consisted of a "cat's whisker" (a fine wire) which was placed on the biggest piece of Galena you could come by. Eventually you found a good spot, and you could hear stuff. Today's "crystal radios" use semiconductor diodes. Cut Numbers- The use of letters in place of some or all of the Morse code characters for numbers, which get rather long in a whole series of figures. Simplest is the long dash - a T, really - for zero. "N" is common for nine. Hams say "5NN" a lot. Means they like your signal. "A" is good for one. And so on. Cynthia- The female voice of the "counter" numbers transmission, which is pretty much confirmed as CIA. The CIA in general ("Cynthia from Langley"). CW- Morse code. The letters stand for "Continuous Wave." They date from when spark transmitters, which used a damped wave, were being replaced by vacuum tube radios using oscillators, which gave a continuous wave. Further, that's just what Morse code is, a continuous radio wave being turned on and off, with some shaping, to send coded (as opposed to encrypted) messages. If the wave is modulated to give a more distinctive sound (not done much anymore), you have MCW. Detection- Recovery of information encoded onto a signal by modulation. The first detectors were hunks of quartz, which still work for AM, but many other types are in use. A product detector is one optimized for SSB, instead of a simple rectifier. A synchronous detector is one that locks onto a carrier frequency, allowing an AM signal to be product-detected like SSB (actually ECSSB - exalted carrier single sideband!). This resists fading and allows the broadcast listener to pick the sideband with the least heterodyne or splatter interference. DF- Direction finding. Uses bearings taken with directional antennas to find the location of a radio station, and sometimes, by extension, yourself. Dropsonde- Instrument canister dropped into the eye of a hurricane by weather recon aircraft to take data on the storm's strength and location. Data returns in real time to a console on the plane, usually an AFRES WC-130, though sometimes NOAA's WP-3 Orions. The plane then uses a satellite or UHF to relay to Miami Monitor, the U.S. National Hurricane Center. If, for some reason, satellite links are down, data may be returned by HF voice, often in a proprietary VORTEX form that can be decoded by the public. DSC Digital Selective Calling, the new automated system for maritime ship-to-shore traffic as standardized under the Global Maritime Distress & Safety System. Every radio licensee is given a unique DSC code which identifies that station to computers on the network. DSP Digital signal processing. Basically a computer that lets all the signals in one end, uses software to get rid of whatever isn't in the model of the desired signal, then sends it out the other end. Theoretically has great advantages over analog processing, and could ultimately replace tuned circuits altogether in radios, which would then use simple direct-conversion designs. Duplex- Two kinds: full duplex, where both stations talk and listen simultaneously on two frequencies, reversing them; and half duplex, where one station (typically a base or repeater) has this capability and the other (usually a mobile) does not. The telephone is duplex. You can say something while the other person is talking and they'll hear it. Ship-to-shore radiotelephone works this same way, on two frequencies. A variation used in Morse code is "break-in" which is really semi- duplex in that a station can only talk or listen, but it changes so fast that the operator can actually hear between his own dits and dahs, so the other side can "break" him if he needs a message "fill." SITOR, Simplex Telex Over Radio, an RTTY system used by ships, does something similar in its ARQ (Automatic Repeat Request), where the two stations synchronize on one frequency and alternate bursts of information. EAM- Emergency Action Message. These are coded instructions broadcast on a regular schedule by U.S. military control stations to all assets in the field. Most EAMs are anything but emergency traffic, basically being "carry on" or dummy messages to confound traffic analysis by an adversary, but listeners such as Jeff Haverlah have found some subtle characteristics in EAMs that may indicate that in fact this is not always the case, and that traffic analysis is sometimes possible, as when the Haitian military strike was called off with an unusually long one. A subset of EAM is the "Skyking" broadcast, usually instituted by Offutt Air Force Base near Omaha, NE. These have a distinctive format, and are presumably the nuclear go/no-go codes that would initiate (or call off!) a global thermonuclear retaliation. Skykings are repeated, but often an urgent one is repeated twice, or three times. This is a good indication that something is up. Fading- Periodic decrease in signal, caused by ionospheric propagation. Can be mild, or severe. Can be slow, which is normal, or fast, which is called flutter, and is one indicator of a disturbed ionosphere. FM- Frequency Modulation. A modulation system invented by Major Armstrong, in which the incoming audio signal changes the frequency of the carrier wave. Detection is by superimposing a nonlinear circuit on the wave, meaning that AM radios can get a fair to middling sound by "slope detecting" with their IF filters. FM is a little more resistant to noise and static than AM, but most of the advantages of FM over AM broadcasting are actually due to its wider bandwidth and higher frequency. Foxtrot Tango- Net control of a US joint tracking net in the Caribbean, either antisubmarine warfare or drug interdiction, probably out of Key West, FL. Net assets use TADILs, such as link-11, so most traffic is technical orderwire type of stuff. Also a radio club dedicated to the FT series of Yaesu radios. Freeband- Typically the half MHz or so between the US Citizen's Band (around 27 MHz) and the 28 MHz amateur band. When skip is in, the freeband comes to life with global chatter, unlicensed, but surprisingly slick and well-disciplined. Frequency- The number of times, per second, that any regular phenomenon, including El Nino, earthquakes, ocean surf, sound and radio waves, goes through a complete cycle of a positive and negative peak. In radio, frequency designations replaced wavelengths, as less unwieldy. 1295.5275 MHz is easier to write and say than 0.2315691 meters. FSK- Frequency shift keying. Instead of merely turning the signal on and off, as in CW, FSK shifts the frequency by a specific amount. The result, when tuned through precise filters, gives mark and space tones useful for RTTY and other digital modes. FSK is simple enough, but all the different RTTY schemes in use can get pretty complex. Green- Any secure mode. Traffic is "in the green" when scrambled or digitally encrypted. Typically, you'll hear a station ask to "go green," and that's the last thing you hear that's intelligible until they go "red," aka nonsecure modes. Green Stamp- Usually a US currency note, enclosed with a QSL request, to help make the guy at the other end want to reply. Name comes from obsolete practice of collecting trading stamps and redeeming them for merchandise. HAARP- Catchy acronym for the High-frequency Active Auroral Research Program in Alaska. HAARP is a huge, and rather controversial, research campaign, part of which involves the heating of the ionosphere with HF radio waves. What's really worth knowing about HAARP is that it's only one small part of the biggest research initiative since nuclear physics. An awful lot of time and money, from military and civilian sources alike, is going into this sudden effort to know all there is to know about the disturbed ionosphere. Why? They're not telling, beyond vague descriptions of "auroral electrojet modification," which has potential to create ELF radio waves on a scale large enough to be useful for several military purposes. Harmonic- A signal that is emitted on a whole multiple of its fundamental frequency. In music, harmonics determine the octave. In radio, they create unwanted emissions. Older equipment was very harmonic prone, and so early bandplans gave services harmonically related frequencies. This can still be seen in ham radio, though it is beginning to break down there as well. Harmonic distortion- The tendency of circuitry to create harmonics that were not in the input. It increases the farther the circuit operates from amplitude and phase linearity, hence the popular "Total Harmonic Distortion" as a measurement for audio fidelity. The most nonlinear circuit of all is a rectifier, and stray rectification of RF can create harmonics in thin air, from properly shielded and suppressed transmitters, making the radio engineer's work that much more fun Heterodyne- The combining of signals, either in the air or in a radio, to get frequencies not in either, technically sums and differences. To hear some real good heterodynes, check out the AM channels on CB. Hooter- Not what you're thinking, but the Mexican military traffic recently scrambled with a hooty-sounding system that may be using some kind of vocoder. K Index- A quasi-logarithmic range index describing the amount of magnetic field disturbance in the preceding 3 hours. In plain English, K is a number from 0 to 9, lower being better, which is more timely than the A index, and a good indicator of what the HF bands are doing right now. In fact, A is derived from the last day's Ks. K is peculiar to a given site, except for Kp, which is planetary. Lincolnshire Poacher- A British numbers broadcast, aimed at the mideast, named for the folk tune that starts it. Link-11- US Navy tactical data link using 16-tone radio modem, often on HF. There are several other TADILs, but not usually on HF. If you have your BFO on (radio in ssb or cw mode), Link-11 sounds like a series of repeating beeps followed by a grunty hiss. Currently a new system is being developed to replace Link-11. Magnetic Storm- Colorful name for a solar-terrestrial incident in which disturbances from the sun make the Earth's magnetic field shift. The more the shifting over a set period, usually three hours, the larger the storm. These range from minor to severe. A severe storm is nothing to sneeze at. At a minimum, short wave radio will suffer, and at a maximum the Faraday effect from moving magnetic lines will turn long AC wires, pipelines, and even satellites, into electric generators, with disastrous (and expensive) results. Magnetic storms are caused by energetic protons, or enhanced solar wind, and they occur 24-36 hours after the optical and RF evidence of a solar event are observed, if they occur at all. There's a certain amount of waiting for the other shoe to drop. Power companies and other people are very interested in predicting these storms. A number of new satellites really help observe these phenomena from points often well removed from the ground. For example, the SOHO satellite orbits the sun, not the Earth, at a Lagrange point where it can maintain a consistent station. Mainsail- General call: "Hello any station this net" (USAF) Nightwatch- old general callsign for the United States military airborne command post network (the "doomsday net" that would take control in a nuclear war). Still called the "nightwatch net," but rotating callsigns are now used for all players. No joy- Station didn't raise anyone. I didn't hear you. NUCO- Nothing to do with "nuclear." Means a numerical encryption code. Procedure is "NUCO - encoded figures - un-NUCO." Technically it's a digraph code, where each number figure becomes two letters. Numbers- One or all of many recurring, encoded transmissions, presumably aimed at spies, that have been tantalizing shortwave freaks for decades. Some "numbers" are really letters, music, or just funny noises. Numbers are probably as old as wireless communication, but the current round began in the Cold War, and, just to make matters that much more interesting, did not end with it. I think it's safe to say that there are more numbers stations on today than ever. Playground- All linked assets, usually Link-11, though there are other TADILs in use. Area of operation. The wide-area network in use. Propagation- A fancy name for a simple thing: how signals get from there to here. Simplest is line-of-sight propagation, basically the same thing a flashlight does. It is limited by the radio horizon, a little farther away than the optical horizon that you see. Other signals on the utility bands are usually from groundwave or skywave. Groundwave signals achieve over-the-horizon coverage by hugging the ground, most commonly on frequencies below HF. Skywave signals come down from the sky, at much higher angles, requiring much different antenna types. They are most typically returned to ground by a very complex process of absorption and reradiation in the earth's ionosphere. Ionospheric skip is strange and wonderful, and most precisely described with all kinds of fiendish integrals and quantum-mechanical things, but for the radio user, the image of a radio wave bouncing is close enough for rock 'n' roll. The signal goes up, bounces off the ionosphere, and comes back somewhere else, from 100 miles (160 km) to clear around the world. It's like bouncing a pool ball. Now, in the case of HF, the pool ball actually turns into two unpredictably colored and strangely bent elliptical spheroids, but that's another story and one that it is best not to think about here. PM Phase Modulation. This is the changing of the instantaneous phase angle of a carrier to match the incoming audio. It's kind of mathematical, but the result sounds a lot like FM. You can tell the difference on a scope, but not always by ear, after the PM is processed by the transmitter. Most of the FM we hear these days is really phase modulation, since varactors are cheap and effective. They change reactance (a form of AC resistance) fast enough to phase-shift the carrier, which can then be multiplied to the final working frequency. PM is also coming into wide use in modems. Straight frequency-shift keying has its limits, but phase-shifting the carrier as well can make for much more bandwidth. Reach- AMC transport, followed by tail or mission number, from the "global reach" of the US military. Russian Man- A numbers broadcast, uh, with a male voice in Russian. Now, in practice, the voice is so high and weird sounding that it sounds female half the time. Also, there are other languages. Hence the alternate name, "Russian Family." Selcal- Selective calling. Any of several schemes for activating a radio or data terminal at the desired station while allowing all others on a net to keep their systems muted. Calling a station thus consists of sending the right numbers or audio tones, and they will either answer or not. Selcals are widely used on HF maritime and aeronautical circuits. Shortwave fadeout- The "radio blackout" of song and story. These really happen, by several different mechanisms, making HF marginal or useless for periods of minutes to days. Most striking is the sudden ionospheric disturbance (SID). This is caused by large solar flares hitting the entire daylight side of the Earth with intense bursts of X-rays and extreme UV. The ionosphere on the lit side absorbs this energy, turns to an entropic soup, and becomes rather opaque to radio waves in a matter of seconds. To simulate this effect at home, turn off your radio. The sound is the same. I've been fooled more than once, and have had to find a local station or a powerline noise to make sure my receiver still worked right. SIDs last around 45 minutes, and mild ones can be worked around by going higher in frequency. (Oh! So that's why HF allocations go to 26 MHz!) The more gradual shortwave fadeouts (G-SWF) come from the sudden commencement of magnetic storms, usually 36-48 hours after the flare, but only if the Earth is in position for enhanced solar wind (the dreaded "proton event"). Conditions improve abruptly (Wow! New DX catches for YOU!), and then deteriorate, slowly and sickeningly, to just plain depressing. One major reason for the wholesale adoption of satellites was to work around this inherent problem with HF. Unfortunately, it didn't turn out quite this nice. Ask the next satellite type about solar- induced magnetopause crossings, radiation burnouts, or loss of station.............. Simplex- A radio mode in which a station can only transmit or receive, talk or listen, at one time, but can't do both. Simplex is indeed simple, as all stations alternate on one frequency, but everyone has to remember not to talk until it's their turn. Most radio procedure has developed to facilitate this rather odd means of conversation. CB is simplex, as is most ham radio below 29 MHz. Single Sideband- Popular voice transmission mode that increases efficiency by sending only the essential analog information needed to replicate understandable speech at the other end. It is basically AM, amplitude modulation, the same as on the AM broadcasting band, but it has been processed to remove that which is no longer needed after modulation takes place. All that is transmitted is the sum of the original radio wave (the carrier) and the voice (the audio) or the difference between these. The resulting radio bursts are the upper sideband (sum) and/or lower sideband (difference). These make a quacking sound until the carrier reference is restored in the receiver. SSB is a huge improvement over AM or FM for voice-grade communication. It is not only more efficient, but it is relatively anti-fade and anti-jam, when compared to either of these other modes. Skip- Ionospheric propagation. Technically, just about all HF utility is skip. On higher frequencies, say 26 MHz up, the line of sight mode predominates much of the time, so a skip "opening" is a pretty dramatic change. Usually a skip path has a relatively dead spot in the middle, the skip zone, which is great for confusing HF listeners. Skybird General call used by any US Air Force plane, not heard much. Skyking- General call for STRATCOM: special EAM follows Spark transmitter- Marconi's original scheme for making RF at commercially useful powers and frequencies. An electric spark in a special gap is loosely coupled to the largest antenna that money and common sense allow. If the thing doesn't catch fire, always a bit if in these circuits, the resulting RF can be keyed by interrupting the primary side, making a buzzy sort of Morse code. Primitive spark transmitters just blasted DC to daylight, while more sophisticated, rotary, ones could be made to send on several "waves" (frequencies), with a fairly good tone quality. These were even amplitude modulated, for voice radio, with telephone mikes hooked right into the high-current primary. The lifetime of a mike thus abused was in the minutes, so many strange rotators existed to keep switching in new ones, while the others cooled just like the other barrels in a Gattling gun. King Spark was on the way out, for Alexanderson alternators, when vacuum-tube CW completely replaced both systems. Spark transmitters are so incredibly broad as to only be useful as jammers now. Therefore, their use is illegal in the U.S., except for special demonstrations. This is most definitely not a device for persons afraid of electricity. Splatter- The effect of a nearby signal upon the one you are listening to, where all you hear are distorted audio frequencies, the splatter, which sometimes are, shall we say, somewhat in excess of what good radio engineers really ought to allow onto the air. To hear real good splatter, try the 30-meter broadcast band at night. Spoofing- On HF, usually the act of deceiving an adversary by posing as friendly and duplicating their radio traffic, but with your desired bogus information. Spoofing makes it mandatory that any radio messages be challenged and authenticated. Standard procedures exist for this, both on the air and in computer networks. Spook- Classically, a spy. Might also be any other type of secret agent who would need to lurk around and use the radio. Spread Spectrum- An interesting communication mode first used in World War II, where the frequency changes so rapidly as to make signals more or less undetectable to anyone else. The simplest mode, frequency hopping, was invented by movie star Heddy Lamar, who was married to an engineer at the time. It used 88 discrete frequencies because the control was a piano roll, and that's how many keys there were. Spread spectrum has proven very robust for HF, not only somewhat anti-jam but anti-fade, and it will become common, using various computer algorithms. Static- Characteristic popping/crackling noise made by RF from electrical sparks, usually discharges of static electricity. These discharges can range from tiny sparks when someone opens a curtain nearby to lightning strikes so huge that their RF propagates around the world. In fact, static increases in the summer, due to thunder storms in tropical and subtropical latitudes. All HF noise is not static, but all static is noise. Sunspots- Misunderstood areas of magnetic disturbance on the sun, which appear in pairs and cluster in active regions, inside brighter "plage." Sunspots are cooler than the surrounding atmosphere, thus appear dark. They appear more frequently as solar activity increases in its 11- and 22-year cycles. Since radio propagation improves at the same time, the "sunspot cycle" is considered a shortwave factor, though the real culprit is increased EUV and X-ray from the churned- up sun. If the twisted magnetic fields holding sunspots together rupture, the result is a prominence or a solar flare, with several possibly dramatic effects for terrestrial and space communication. Solar flares routinely cause severe disruptions in just about anything electric or electronic on this planet, all the way from advanced communication satellites to carrier pigeons (which sense the geomagnetic field). Flares have always done this, and we are still here, but the news media have recently picked up on this as their latest doomsday scenario. Balderdash. Solar flares are awesome, but not fearsome. Superheterodyne- Receiver design invented by Major Armstrong, for RCA, which uses a local oscillator to heterodyne all signals to the same intermediate frequency, typically 455 kHz, greatly aiding optimization of the circuitry. Just about all modern radios are superheterodynes. Superregenerative- Receiver circuit that uses a regenerating (self-oscillating) stage to increase sensitivity. The maximum gain point is usually right before the radio breaks into an awesome feedback squeal, making some very strange noises come from these receivers. Further, the oscillating stage is at RF (no IF), so considerable signal is radiated back out the antenna. This, of course, has harmonics, and is another reason that harmonically spaced allotments were originally used. Today, the major use for these radios is to demonstrate what HF users had to put up with in the Bad Old Days. Surface Proton Event- A solar mass ejection (protons are hydrogen nuclei, and they have mass), and resulting magnetic storm, which is strong enough to produce auroral current measurable all the way down to the ground. Has no bad health effect, really it doesn't, but it can really mess up communication. TACAMO- Take Charge And Move Out, the U.S. Navy's airborne command post mission. Most unusual capability was/is the VLF communication with submarines. Over water, a wire could be reeled out the back of the airplane for several miles! It is widely believed that "request you echo the following" in an EAM is the call for a TACAMO to rebroadcast the message over VLF. Traffic analysis- The ongoing attempt to discern information from the statistical characteristics of a radio network. For example, if a quiet frequency were to come alive with military chatter, it would be safe to conclude that a major troop movement or exercise was underway. Therefore, many military nets broadcast dummy or "carry on" messages in the same format, to avoid sounding different when something happens. One major aim of tactical deception has always been to make an adversary "discover" false information through such analysis. The classic case is Operation Overlord in World War II, which used a great deal of false communication to help convince German troops that the D-Day invasion would take place in Calais instead of Normandy. US military traffic analysis is difficult, but not impossible. There are a few subtle characteristics in EAM broadcasts, for example, that can sometimes be exploited by experienced utility listeners. Test slip- Any RTTY tape or buffer that sends an automatic transmission, from the days when strips of paper tape were used. The most common test in English is the "foxes," a repeat of "The Quick Brown Fox Jumped Over The Lazy Dog," using all the letters. The French language version, "Voyez le brik..." has something to do with ships in the harbor. Baudot tests usually include "RYRYRYRYRYRY," producing a distinctive chirpy sound which also uses all the possible bit-states. A similar strip, the "brag tape," was a standard message that one could send out, presumably much faster than their typing speed, bragging about all their great equipment and general RTTY prowess. "Loop" has the same origin, from a repeating paper or magnetic tape loop. Triangulation- Technique of precisely locating a radio signal's source by finding the intersection of two distant bearings. It is not always reliable on HF, due to uncertainties in propagation paths. This doesn't stop everyone from doing it, rather successfully with lots of training and a little luck. Wavelength- The, uh, length of a wave. The distance between similar peaks of any recurring phenomenon in space. The inverse of frequency. Wavelength, in meters, decimeters, centimeters or millimeters, is still often used to describe areas of the radio spectrum. A 20-meter ham radio is one that uses 14 MHz, not one that has 20 pointer devices for measuring internal circuit parameters, though if you get far enough into boat anchors, it might have these as well. Whales- A really spooky "whale sound" heard on HF. The US Navy is the most likely culprit. The most popular theories are: (1)Excessive no-signal compressor gain in landlines feeding remote transmitters, causing audio feedback. (2)Drifting pilot tone in ACSB circuit accidentally left open. (3)US Navy telemetry buoy (4)Submarine communication device using a trailing buoy Winchester- Military speak for "out of ammo." World Day- It's too expensive for everybody to watch the sky all the time, so the various science groups co-ordinate a schedule of special observing periods, one of which is the World Day that one hears about in radio science. Special World Days are called if something really good happens on the sun. Fans of HAARP should note that its research "campaigns" are World Days or World Intervals. Good way to keep tabs on the beast. Wouff Hong- Wooden instrument of destruction, vaguely resembling something that might be used in proctologic examinations, and apparently meant to discipline CW operators who interfered or generally got in the way. Invented by Hiram Percy Maxim, an early ham, after some of the grunge on the air was copied as these two words. While a bloody Wouff Hong is brought to midnight initiations at radio conventions, there is no evidence of its actually ever being used in anger. Another, even more fearsome instrument, with a crank on one end, is called the Rettysnitch. Ouch. X-ray Flare- A solar flare big enough to produce measurable X-rays in space (usually sensed by the GOES satellites in geosynchronous orbit). Astronomers refer to these as class X, followed by a number that increases with measured X-ray intensity. Anything above X13 to X15, however, will probably saturate the detectors, and not be accurately recorded. These are the solar events that can totally blow out HF. # # #