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EDITORIAL
To read the entire article, subscribe to INFOCENTRAL News, Trends, And Short Takes by D. Prabakaran
HD Radio Test In Germany Radio Regenbogen, one of Germany’s private radio stations, and network operator Media and Broadcast of T-Systems, have announced the start of an HD Radio technology field test at the end of August. Listeners in the Rhine-Neckar area will be able to receive the Radio Regenbogen program as well as two multicast formats: Regenbogen Gold and Regenbogen Comedy. The testing is also supported by Ibiquity Digital, Audioexport Georg Neumann, Orban/CRL Systems, Broadcast Electronics, and Ruoss, a company that has assisted with HD Radio tests in Switzerland. The first test results are to be presented at an event of the Regional Office for Communication that will be held in Stuttgart on September 27, 2007. German Public Broadcasters Launch “Sparse Image Audio Service” Trial A “sparse image audio service” trial has been launched by German public broadcasters WDR in Cologne and MDR in Leipzig. In the area of greater Cologne, the proposed broadcasting location is the “Kölnturm” (Cologne tower) in Mediapark with an aerial height of 160 meters. The DMB multiplex is on channel 11D, and the radiated power of 10 kilowatts is aimed at in-house coverage for Cologne city center. Trial broadcasts consist of existing TV programs as well as visually enhanced radio programs; for example, displaying the CD cover of a track being played or a road map with traffic news.
The DAB/DMB technology employed was developed
in co-operation with the Fraunhofer Institute for Telecommunications,
Heinrich Hertz Institute (HHI) in Berlin. Instead of the usual DAB format,
however, a High-Efficiency Advanced Audio Coding HE-AAC radio format is
being used, reducing the bandwidth from 192 kilobits per second to 48
kilobits per second.
Minivan Radio, the Maldivian opposition
station, will end its current series of shortwave transmissions on August
31. The shortwave broadcasts, at 1600 to 1700 UTC on 11965 kHz, were
resumed on August 1 after four months during which they had been available
only via the Internet. The station had stopped the broadcasts in
anticipation of winning an FM license, but has so far been unable to
procure one. It’s likely that further shortwave transmissions will be made
to cover significant events.
To read the entire article, subscribe to WASHINGTON BEAT Capitol Hill And FCC Actions Affecting Communications by Richard Fisher, KI6SN
FCC Praises BPL In House Testimony, Radio Amateurs Respond FCC Commissioner Jonathan S. Adelstein testified at a House Subcommittee on Telecommunications and the Internet hearing that “three of the many urgent priorities we face” include the need for “a national broadband strategy to ensure the ubiquitous deployment of affordable, high-speed broadband infrastructure to this country.” In reaction, David Sumner, K1ZZ, chief executive officer of the American Radio Relay League (ARRL), reiterated the organization’s position with regard to Broadband over Power Line (BPL) technology and “its propensity to interfere with radio communication, a flaw that is not shared by other broadband delivery platforms,” according to an on-line news release. “As long as interference is avoided, it is of no concern to us whether private investment is devoted to BPL. However, we must object to your identification of BPL as a technology that is particularly deserving of favorable public policy treatment,” Sumner said. FCC Chairman Kevin Martin and Commissioners Deborah Tate, Robert McDowell, and Michael Copps also testified at the “Oversight of the Federal Communications Commission” hearing. Sumner said that according to the Commission’s latest figures, “of 64,600,000 ‘high-speed’ lines, only about 5,000 are BPL. This is a share of 0.008 percent, a share that actually declined in the six-month period between reports—and if an ‘anemic’ definition were not used, none of the 5,000-or-so BPL lines would qualify.” The ARRL’s concern, Sumner said, regarding the “prospect of an even greater encouragement of BPL, as your testimony suggests, is that—even at the very low level of deployment that exists to date—the FCC’s enforcement efforts have proved to be woefully inadequate to address ongoing cases of harmful interference from BPL systems.”
To read the entire article, subscribe to Digital Two-Way Radio Technology Reaches Consumer Market
Frequency-Hopping
Spread-Spectrum by Bernard Bates
For over a quarter century, Popular Communications has progressively covered developments in CB, GMRS, FRS, and MURS because they’ve been the most popular forms of personal two-way radio communications. Now a paradigm shift is about to dramatically change how we communicate via two-way radio, thanks to developments in digital frequency-hopping spread-spectrum (FHSS). This represents a logical progression in the trend from analog to digital radio that has so changed the cellular radiotelephone industry and numerous local, state, and federal two-way radio systems.
To see where we’re headed with personal
two-way radio communications it’s helpful to look back at its history, so
we’ll briefly cover its evolution. We’ll also explain some of the reasons
behind the emerging trend from analog to digital personal two-way radio
communications, while examining the greater capabilities and advantages
digital radio offers (as well as its potential downsides).
Analog two-way radio has been around for over
a century, first using Morse code (CW) and later voice communications
using amplitude modulation (AM) technology. But the average consumer had
no readily accessible form of personal two-way radio communications until
over half a century later, when CB radio entered the scene. What followed
was a series of evolving popular communications explosions, demonstrating
that the American public has an insatiable appetite for low-cost,
portable, two-way radio communications options. The evolution of these
communications options is accelerating and is poised to enter a new era.
The first popular two-way radio service used
by the general public (without any required technical exams, such as
Amateur Radio requires) was the Citizens Band Radio Service, which was
originally created by the FCC in 1958 by reallocating much of the 11-meter
amateur radio band’s 27-MHz frequencies. CB became a staple of personal
communications for millions of Americans, and it skyrocketed in popularity
during the 1970’s CB culture craze. But its relatively long 11-meter
wavelength made handheld CB radios unwieldy with their long antennas, so
CB was relegated primarily to vehicular use.
To read the entire article, subscribe to
Zombie Army Of The
In 1968, a student attending Carnegie Mellon University in Pittsburgh, Pennsylvania, by the name of George A. Romero, wanted to make some extra money. Being interested in filmmaking, he began producing TV commercials and industrial films in his spare time and the endeavour became a success. He and a group of friends were soon running a full-time business, but, being young, they wanted to do something more exciting than make commercials about used cars and soap. What they really wanted to do was make a horror film and, by using their connections in the film business, they were able to borrow $114,000 to do so. To keep production costs down they used black and white film, which allowed the use of ordinary chocolate syrup as a substitute for authentic theatrical red blood, which was expensive. Movie critics of the day hated the film for its violence and poor production values, but the public loved it, and it eventually grossed over $42 million.
Despite its flaws, there was something special
about the story, so much so that, in 1999, the Library of Congress entered
the film into the United States National Film Registry along with other
films deemed “historically, culturally or aesthetically important.” The
reason, plain and simple, was that this cheap horror movie came to define
in the public mind the Zombie archetype that we still cringe at today! The film in question was, of course, Night of the Living Dead, where Barbara, Ben, and a small handful of survivors fought off reanimated corpses while trapped in a small farmhouse in rural Pennsylvania. What made the story so compelling was the fact that anyone could become a Zombie since they were “recruited” from live people. Good, bad, young, or old, everyone was vulnerable to becoming a Zombie, and all it took was for a person to be bitten by a Zombie! Almost immediately that “bitee” died, was re-animated and lurched around with one goal: find another person to bite! What made the movie so scary was how determined the Zombies were to make more of themselves.
Getting rid of a Zombie was no picnic either,
as they were already dead. The next thing you know—everyone’s a Zombie!
To read the entire article, subscribe to Thanks For The (Digital) Memories
The
Future Of Technology Actually by Tom Swisher, WA8PYR
Have you ever taken a stupid pill? Remember the scene in the movie Johnny Dangerously when Johnny (Michael Keaton) hangs Danny Vermin (Joe Piscopo) on a hook, to which Danny replies “You shouldn’t hang me on a hook, Johnny. My father hung me on a hook once. Once!” Well, I took a stupid pill once. Once. The result has been involvement in a pretty fascinating aspect of the monitoring hobby.
That stupid pill resulted in my acquiring a
Model 15 teletype machine. If you’re one of our younger readers, you might
be asking “a what?” You probably know it, though. It’s that large, ugly,
noisy, clattering, dinging green or gray box spewing forth reams of
yellowish paper in the back of the newsroom on so many movies and
television shows. Yes, they really do make that clattering noise, and even
an occasional series of “dings” from the bell!
Radio is different, of course, since there’s
obviously no telephone circuit. Teletype modes are handled on radio by
either shifting the frequency of the transmitted signal (Frequency Shift
Keying, or FSK), or by shifting the frequency of the audio tone being sent
(Audio Frequency Shift Keying, or AFSK). Of the two, AFSK is easier to
implement, as it simply requires a connection to the microphone and
speaker jacks of the transceiver to be used, whereas FSK requires certain
modifications to the transmitter. My first experience with teletype was in my college ham radio club in 1982. A Model 15 (probably a hand-me-down from the newsroom at the university TV station or newspaper) was resident in the shack, along with a homebrew terminal unit, which allowed the beast to be connected to the radio equipment and used for RTTY (Radio TeleTYpe). I was fascinated with the thing, and made it my goal to make it work again. It took some doing, but I finally got it going, and in short order reams of teletype paper were spewing forth a cornucopia of text from sources as diverse as ham radio operators, the Associated Press and other assorted news outlets, and the military. I
To read the entire article, subscribe to German Wireless Of World War I
Early
Radio Technology Foreshadowed by R.B. Sturtevant, AD7IL
It was over. At 11 a.m. on November 11, 1918, the four years, three months, and 14 days of the Great World War came to an end. It started when the Austro-Hungarian Arch-Duke Francis Fredrick was assassinated in Sarajevo, and ended in a railroad coach in the forest of Compiegne, France, after Europe was nearly bled white. Twenty-four nations had raised 42,188,810 soldiers and sailors for England, France, and the other Allied Powers and another 65,038.810 souls struggled for Germany and the Central Powers. Casualties had amounted to a total of 11,016,000. The Allies lost a staggering 52.3 percent of their total raised forces, and the Central Powers suffered an even greater 57.6 percent of theirs. In all, approximately 7,450,200 human beings lost their lives. The Allies had spent $125,690,477,000 in American dollars
of the day. The Central Powers had paid out
$60,643,160,000 and were nearly bankrupt. But had any good come out of the “War to End All Wars”? One benefit did come out of this—as all wars: the improved technology that, when the shooting finally stopped, was put to work making the lives of average people better and more comfortable.
The two most noticeable improvements after WWI
were in aviation and communications. The slow evolution of the airplane
from the time of Kitty Hawk in 1902 to 1914 gave way to rapid advances at
twice the pace during the war years. Telegraph and wireless made at least
equal leaps forward, both in the number and quality of sending and
receiving stations as well as the number of trained operators. This improvement was clearly evident when Germany surrendered 122 of her feared U-boats to the Allies. Some of these U-boats wound up in Portsmouth, England. Four of the undersea killers were turned over to American crews attached to the British Flotilla. Not well publicized was the fact that American submarines had been working with the British in European waters for over a year. Among these American sailors was an amateur operator named J.A.
To read the entire article, subscribe to SCANTECH RadioReference.com—The Place To Be by Ken Reiss
Getting good frequency information is always a big challenge for scanner enthusiasts, whether they’re just getting started or are old hands. Frequency usage changes just often enough to make a completely up-to-date and accurate database difficult at best. RadioShack used to carry and recommend Police Call for new scanner users. But times have changed, prompting this letter from Dan S. Since there is no more Police Call at RadioShack, or anywhere else for that matter, Dan wrote in to ask what is the best website for current scanner frequencies. I’m glad you asked, Dan, as I’ve been struggling with that same issue. The good news is that there is significant help available at a site called radioreference.com. Described on its homepage as “the world’s largest radio communications reference,” it offers vast amounts of information on conventional frequency assignments, trunked radio systems, frequencies, talkgroups, FCC License assignments, maps, and so much more. Since a picture’s worth a thousand words, I thought it would be helpful to take a look and see what they have to offer in pictorial form.
To read the entire article, subscribe to HOMELAND SECURITY What Price Communications? by Rich Arland, W3OSS
This month we’re going to start a multi-part series designed to get many of you (myself included) off of dead center and doing something positive regarding increasing our collective readiness to provide emergency communications. This issue’s column will deal with my efforts to fabricate a “Bug-Out Box” based upon the equipment I have on hand at the Arland Ranch. My idea is to design and fabricate a quick reaction comm package tailored to my unique EmComm requirements without plunking down any more of my hard-earned money to buy more gear. Your assignment: provide me with feedback, including pictures with captions and a brief write-up of your efforts to build your own Bug-Out Box or “Go-Bag” in support of your emergency communications taskings. Best part of all, if you impress me with your innovative, outside-the-box (pardon the pun) thinking, originality, and initiative, I will showcase your handiwork in an upcoming “Homeland Security” column and you will win a one-year subscription (or one-year renewal) to Popular Communications courtesy of yours truly. More on this later.
Now, let’s get down to brass tacks and build
us a portable quick-reaction package for emergency communications. Face it; if you’re a ham radio operator, scannist, SWL, DXer, or emergency communications first responder, you are a gadget-happy dude (or dudette). It goes with the territory. About the only hobby that fosters more gadget happiness is photography, and interestingly enough, one of the major sideline hobbies for radio enthusiasts is photography.
Alas, we’re doomed! Collecting “stuff” is
natural, even more so in the radio hobby. I mean we collect stuff just to
have stuff. The stuff we collect basically amounts to all sorts of junk
(or more specifically, “junque,” which is just like “junk,” only cooler).
We really can’t use it right now, but we know sometime in the future we
will need that little trinket, come hell or high water! What this means is
that most of us have quite a collection of junque in our junk boxes with
which to design and fabricate all sorts of unique communications projects.
So let’s get busy and build a Bug-Out Box for emergency communications.
To read the entire article, subscribe to GLOBAL INFORMATION GUIDE Voice Of Tajik Waxes, Radio Nationale Tchadienne Wanes, And VOA Gets A Reprieve by Gerry L. Dexter
Well now, here’s a switch. In an age when
stations are cutting back and governments are busting broadcasters’
budgets, the state radio of Tajikistan is doing just the opposite! The
Voice of Tajik (locally Ovazi Tajik) is expanding! The station is, or soon
will be, operating for 16 hours a day (0200 to 1800) using seven
languages, including English. The earlier morning hours on higher frequencies should provide us with the best chance to hear Tajik Radio. Reports can go to International Service, Tajik Radio, P.O. Box 108, 734025 Dushanbe, Tajikistan. As this is compiled, there aren’t any known logs yet, but that could change at any time. Another former Soviet state is also making changes. Radio Belarus has begun to relay its 24-hour local BR-1 service on all its shortwave frequencies: 6010, 6040, 6070, 6080, 6115, 6190, 7110, and 7145. Historically Radio Belarus doesn’t usually shake the shutters with its signal strength, so this may prove to be a bit of a toughie.
Bolivia has a new one in operation. Radio
Universitaria is using 4732 from the local university campus in Cobija.
It’s active from 1000 to 1300 and 2200 to 0200. The seldom-received Wontak Radio Light in Papua New Guinea has stopped using 7120 and is now found on 7325, sometimes with relays of PNG’s National Broadcasting Corporation. Also, the equally difficult PNG station on 4960, at first called the Catholic Radio Network, has been re-named Radio St. Gabriel. Eventually it will join the Catholic Radio Network there. Radio Romania International has cut back on some of its broadcasts. Atypically, this news is not shrouded in concern. The cutback is only temporary as RRI modernizes its transmitters and antenna systems at both the Tiganesti and Galbeni sites. I’ve noticed a degrading of reception from Romania in recent years but just chalked it up to poor propagation. Apparently other factors are at work.
To read the entire article, subscribe to
POWER UP: RADIOS & New, Interesting, And Useful Communications Products
Those of you heading out this fall to tackle
the maintenance of rusted, corroded antenna and tower hardware might want
to bring along a can of Blaster Corporation’s PB B’laster (Part #16-PB),
an all-purpose penetrating catalyst that can also be used as a lubricant
and rust inhibitor. According to the company, PB B’laster’s capillary
action allows it to squeeze into the tightest cavities and attack rust
from all angles. Its surfactant works on parts even when they’re wet, and
it displaces moisture. PB B’laster costs $4.50. C. Crane has announced a new addition to its product line, the CCRadio-SW AM/FM/Shortwave Radio. According to the company, the radio’s built-in Twin Coil Ferrite AM Antenna provides AM reception in the same class as the CCRadio plus, in addition to FM. As a shortwave receiver, right off the whip antenna, it combines sensitivity, selectivity, and audio performance unusual in a radio of this price and size (7.25 x 11.25 x 3.5 inches HWD; weight: 4.2 pounds). The five-inch speaker is accurate, pleasant, and reproduces deep bass sounds. The CCRadio-SW offers a large, easy-to-read LCD display. Its features include RF gain control, bandwidth control, bass and treble controls, fast and slow tuning, 50 memories, lighted buttons, stereo line output and headphone jack, and IF Output for input to a computer. It runs on four “D” size batteries or four backup “AA” batteries (not included). A built-in charging circuit will recharge optional NiMH batteries right inside the radio. AC Adapter and antenna connectors included.
The cost is $149.95 with free shipping. For
more information, visit www.ccrane.com.
To read the entire article, subscribe to REACT IN ACTION Know The Joy Of Serving
by Ron McCracken, KG4CVL / WPZX486
Missing child! Word spread through our school like wildfire. Nothing strikes terror in any heart like those two words. The police were alerted. A search was mounted in no time by anxious parents and teachers. Some had CB radios. Quickly, we realized how much those radios increased the efficiency of the searchers. Late that night, the student was found safe and sound, in a railway station, 40 miles away. The lesson of the CB radios stayed with me. Soon, some of those searchers launched a REACT Team to serve our area in future emergencies. That was my introduction to CB radio, and to REACT. For almost 30 years our REACT Team has continued to serve its community and the surrounding area with safety communications. Over those years it has built a close relationship with police and other emergency services it supports. Years later, another student was struck and killed as he bicycled on a nearby highway. Although that outcome was tragic, our REACT Team took consolation in knowing that its CB radios had sped help to the scene in minutes. Emergency personnel arrived as fast as humanly possible, all thanks to those CB radios. Luckily, happy endings far outnumber the sad. Our REACT Team helped summon aid for a disabled ice fisherman trapped in a sudden blizzard that swept our lake. REACT monitors have assisted a number of boaters in distress on Lake Simcoe, Ontario, Canada, over the years, too. I hope I helped save a driver stranded in his big rig during a Kansas blizzard one bitter cold February night. “Skip” propagation brought that call in at 2 a.m. It took 30 minutes to piece together from his broadcasts the information I needed to give his dispatcher. What a glow of satisfaction you experience after helping with such an incident. I never did hear the outcome of that call.
And those are only just a few of the many
REACT experiences that have thrilled just one Team over the decades.
To read the entire article, subscribe to BROADCAST TECHNOLOGY DXpedition! by Bruce A. Conti
There are two common denominators to all of
these DXpeditions. Foremost is the location, as each took place on the
seashore. The combination of the high conductivity of salt water along
with a clear horizon creates optimal conditions for long-distance
reception. Secondly, the 800-kW signal of Radio Farda on 1575 kHz from the
United Arab Emirates was logged at all locations, an amazing testament to
the advantages of high power and a “split” frequency exactly halfway
between the domestic channels of 1570 and 1580 kHz. Each report includes
selected logs, all times are UTC. Recently, aspects of my life aligned so that I was able to fulfill a lifelong dream and visit fabled Easter Island in the southeastern Pacific. Although my primary purpose was to visit the myriad archeological sites, view the hundreds of giant stone heads and get to know the inhabitants of this “most isolated community in the world,” I could not possibly visit such an exotic location without testing its potential as a location for very long-range mediumwave DXing. Since the nearest concentrations of MW broadcasters were on the west coast of South America, 2,300 miles to the east, and in New Zealand, 4,300 miles to the southwest, there was every likelihood that Easter Island might be a prime DX location. Easter Island is a triangular volcanic island measuring about 10 miles on a side. The 3,300 inhabitants are concentrated in a single village, Hangaroa, on the southwest corner of the island, also the only location of an AC power grid. Since I knew that I would be 12-volt DXing from, at best, a rental car, and since I was quite concerned about luggage weight and security screening, my DXing equipment choices were both critical and limited. After a good deal of thought, I chose the marvelous Eton E1-XM as my primary receiver and the small Kaito KA1103 as back-up; the Eton E1-XM had recently supplanted my long-cherished Sony 2010 as my favorite DXing portable. I was not disappointed in either receiver!
To read the entire article, subscribe to RADIO RESOURCES Some Of The World’s Remotest Islands Go Radio Active by Gordon West, WB6NOA
Sailors heading to and from Hawaii from the South Seas rely on marine single sideband for weather reports and direct contact with the United States Coast Guard in the event of a medical emergency. The best time to intercept these skywave marine sideband signals is in the evening to 0000 hours Zulu (Universal Time Coordinated).
These are the most easily heard frequencies,
coming out of the South Pacific, heard here in the United States.
Marine single sideband is the principle
“intercom” for sailors to help one another during their long three-week
passage between Hawaii and the hundreds of islands in French Polynesia.
For an emergency, there is only one tiny hospital along the route,
situated just miles north of the Equator. “Classified by the World Health Organization (WHO) as one of the most remote and most medically needy atolls in the world, the Line Islands are 1,200 miles south of Hawaii and almost 1,200 north miles of Tahiti. They offer sailors emergency medical help in the middle of nowhere,” said Carlton Smith, T32CS, KE5EUL, a philanthropist who regularly gets medicines, supplies, eyeglasses, and radio equipment to the three Islands, Kiritimati (Christmas), Tabuaeran (Fanning), and Teraina (Washington). These islands are home to 9,000 villagers who mostly live a subsistence life, surviving on fish, coconuts, and some imported rice they pay for by trading dried coconut (copra). The one hospital, and its English-speaking doctor, Dr. John, is located on Christmas Island and sometimes can be heard communicating on upper sideband HF radio at night on 7312 kHz to the other two islands. This is the long-range radio high-frequency channel that carries life-saving medical instructions among the islands and to their Ministry of Health, 2,000 miles east, in the capital of Tarawa.
Neither of the other two islands had radio
support from the main hospital on Christmas, nor for the nursing stations
on the other islands.
To read the entire article, subscribe to UTILITY COMMUNICATIONS DIGEST
The Lockheed C-130 Hercules: by John Kasupski, KC2HMZ
Niagara Falls, New York, August 2007—As part of the festivities surrounding the “Thunder Over Niagara” air show at the joint Air Force Reserve/Air National Guard base here, several Civil Air Patrol (CAP) cadets climbed aboard one of the eight C-130H3 cargo aircraft belonging to the 914th Airlift Wing (USAFR), which subsequently took off for a demonstration of aerial refueling. One of the nine KC-135R Stratotanker aircraft from the 107th Air Refueling Wing, New York ANG (callsign FUZZY) and the C-130 from the 914AW (callsign BISON) rendezvoused at high altitude, and the CAP cadets got to experience an airborne “gas-and-go,” in which both the aircraft participating were built before most—and probably before all—of them were even born! The C-130 “Hercules” was named for a mythical character, but the aircraft that bears his name has become a legend in the real world. It’s been 55 years since the U.S. Air Force issued the General Operating Requirement that became the C-130, and 52 years since the prototype YC-130, serial number 53-3397, made its 61-minute maiden flight from the Lockheed plant in Burbank, California, to Edwards AFB. It was the second prototype, but the first to actually fly. Today, more than 70 variations of this aircraft exist, and “Herkybirds” are being flown by more than 60 nations—and utility monitors around the world continue to log this aircraft, in its many variations, on the HF airwaves on a daily basis. Perhaps the C-130’s greatest asset, other than its unparalleled versatility, is its impressive short takeoff and landing (STOL) capability. One of the C-130’s first accomplishments, back in 1963, was to set the world record for the largest and heaviest aircraft to land on an aircraft carrier. In October and November 1963, a U.S. marine Corps KC-130F landed (see Photo A) on the deck of the USS Forrestal 21 times—without benefit of arresting gear, no less. It also managed to take off from the Forrestal without catapults. That very aircraft remained in active service until 2005 and is now part of the collection at the National Museum of Naval Aviation at NAS Pensacola, Florida.
Along with that, the C-130 is probably the
most versatile tactical transport airframe in aviation history. Although
designed as a transport aircraft for troops, cargo, and medical
evacuation, the C-130 has also been employed for scientific research,
weather reconnaissance, aerial refueling, aerial firefighting, airborne
assault, search and rescue, tactical and strategic communications, and—in
its AC-130 Spectre variation—as the most powerfully armed gunship ever to
take to the skies. The C-130 has recovered space capsules, worn skis to
land in Antarctica, and conducted maritime surveillance and airborne early
warning.
To read the entire article, subscribe to THE ANTENNA ROOM Family Radio Service Yagis by Kent Britain, WA5VJB
In many areas of the country, the Family Radio Service (FRS) has taken over more and more of the emergency services originally handled by REACT and CB Channel 9. And, of course, several manufacturers offer good, inexpensive devices to meet the growing need (Photo A). A 6-inch rubber antenna may meet the original FCC specifications, but the range is very limited. There are legal issues involved in modifying the antenna on the FRS transmitter, but there are no restrictions on building big antennas, like the Yagi in Photo B, for scanners or ham rigs that also tune 465 MHz. This allows you to monitor FRS radios from four to 10 times farther away than that 6-inch rubber antenna is going to let you hear.
This is a family of easy-to-build Yagi
antennas for monitoring the FRS service. They’re simple and inexpensive
and are great for weekend and portable activities. The two-element Yagi
will cover about a 180-degree arc and, if mounted at a modest height, will
give good coverage. The four-, six-, and eight-element Yagi antennas each
cover a narrower arc, but with more gain and more range. These Yagis also
work well as 460-MHz scanner antennas, all for just a few bucks. I’m not a fan of using plastic water pipe for the element boom, and it tends to melt when you solder the coax to the driven element. But if you solder the coax first then attach the driven element to the boom, plastic pipe can be used. Personally I like to use wood for the boom. It’s cheap, easy to drill, strong, and if you protect the wood, it can last for years and years. Spar Varnish seems to be the best to use, but wood sealers, spray paint, and even house paint have all been used with good long-term results. At this frequency, 1/2 x 3/4-inch wood works well, as does 3/4-inch square. The elements can be any metal about 1/8th inch or about 3 mm in diameter. Hobby tubing, #10 and #12 bare copper wire, ground rod wire, electric fence wire, and welding rod have all been used to make elements. For the driven element I suggest bare copper wire or one of the bronze welding rods; they’re much easier to work with when you’re soldering on the coax connections. After the elements are in place a drop of Super Glue or RTV-type silicone glue will keep them there.
To read the entire article, subscribe to THE PROPAGATION CORNER The Ionosonde by Tomas Hood, NW7US
Readers of this column have read about the ionosphere and how a range of radio frequencies can be reflected by the ionosphere in such a way that we can communicate by radio over distances beyond line-of-sight. The ionospheric density and energy level are both affected by energy from the sun, and they change throughout the day and season, and from year to year. Scientists and propagation observers measure the ionosphere by using special radio equipment called an “ionosonde.” An ionosonde is also known as a chirp sounder, because chirps, or radar emissions, are used to examine the ionosphere. This is accomplished by a shortwave transceiver that can quickly tune through the whole shortwave range, sending and listening on each frequency. Special antennas are used because the transmitting antenna must have the correct matching impedance between the transmitter and the antenna array, and the receiving antennas have to be directional and able to hear signals on each of the frequencies in the sweep made by the transmitter.
The ionosonde transceiver steps through a
series of frequencies from low to high. As it transmits on each frequency
between 1 and 20 MHz, the transceiver sends a rapid pulse straight up into
the ionosphere. Between these pulses, the ionosonde listens for an echo of
the transmitted pulse. The time it takes between the sending of a pulse
and the returned echo is analyzed to determine ionospheric
characteristics. Each echo is plotted by frequency and time on a graph called an “ionogram” (Figure 1). When echoes are no longer returned, the ionogram illustrates the highest frequency on which an echo was returned and shows the return time as a distance from the ionospheric layer from which the echo was returned. These plotted measurements, typically made every 15 minutes, allow the ionosonde to map out the various layers of the ionosphere (the E-, D-, F1-, F2-, and F3-region mappings). Each ionospheric region shows up as an approximately smooth curve, separated from each other by an asymptote at the critical frequency of that layer. According to the entry on Wikipedia (<http://en.wikipedia.org/wiki/Asymptote>), …an asymptote is a straight line or curve A to which another curve B (the one being studied) approaches closer and closer as one moves along it. As one moves along B, the distance between it and the asymptote A tends to become smaller and smaller overall, and eventually never becomes longer than any specified distance. A curve may or may not touch or cross its asymptote. In fact, the curve may intersect the asymptote an infinite number of times, but its maximal deviation from the asymptote keeps getting smaller.
To read the entire article, subscribe to HAM DISCOVERIES QSL Cards: Still Going Strong! by Kirk Kleinschmidt, NTØZ
Now that I’ve turned 45 and have been a ham for 30 years, I can look back on our hobby with a perspective that I just couldn’t muster a decade ago. I am just starting to understand how things transition—in grand fashion—from old to new. The biggest of the big pictures. Now, even though most of the world’s people believe in reincarnation, it doesn’t matter whether you do or not. Personally, I believe in reincarnation, but I don’t believe Morse code should be sent with a bug (unless the operator can send perfectly formed code with the infernal contraption) or that unattended HF digital mailboxes should be allowed to operate in the CW/data subbands...but those are discussions for another time. Take a step back and think about the rapid sweep of technology and where it’s going. Computers are still computers, but they’re enormously faster and more functional than they were just 20 short years ago. Ham radio, too, is zooming ahead—sometimes into uncharted territory. Unlike sailing, for example, which is substantially similar today compared to what it was a hundred, or even 500, years ago, ham radio isn’t the same. We don’t use spark-gap transmitters and, a few enthusiasts aside, we don’t run plate-modulated AM much, either. The regenerative receiver is mostly a novelty, as are magic-eye tubes (tuning indicators) and Nixie tubes (numeric displays). We’re now exploring digital radio, global data networks, global positioning systems, RFID tags tucked away in everything (and soon everybody), ubiquitous cell phone technology, and even virtualized amateur radio simulators that live on the Internet. If you think that these systems won’t supplant what we now think of as amateur radio, ham radio’s first century stands ready to prove you wrong! In ham radio’s 100-year history, things have changed dramatically. And in another hundred years we probably won’t recognize what ham radio has become—if it even exists at all. It’s likely that, in geologic time or from a “reincarnation perspective,” ham radio will have come and gone in a finite, and rather small, window of technical evolution. Think about that! With all the evidence we have to date, the phenomenon we call amateur radio will have been born, matured, evolved and likely “died,” in a 150- to 250-year period. Period!
To read the entire article, subscribe to THE POP’COMM TRIVIA CORNER Radio Fun And Going Back In Time by R.B. Sturtevant, AD7IL
Q. Who paid for and sent the first commercial radio telegrams? A. In June 1898 Lord Kelvin was visiting Marconi’s Alum Bay station on the Isle of Wight, off the southern coast of England. During his visit Kelvin sent telegrams to four other leading scientists working in the field of wireless research to demonstrate that wireless telegraph was available for commercial use. Marconi sent the messages to a shore station on the British mainland where they were put onto the British Postal Telegraph’s wire system. Kelvin paid Marconi a shilling apiece to make it a commercial transaction. The first overseas commercial telegram went out the next day when the Italian Ambassador to England sent a long telegram from the same station to the court of the King of Italy. Q. You’ve mentioned the British took most of April 1982 getting their Task Force to the Falkland Islands before the actual fighting got started on May 1. Did radio play any part in this build up? A. Yes it did. Both sides, of course, were putting out press releases and media information to justify their particular point of view. But you probably would expect that. Something that you might not expect was that, as soon as the British Task Force came in range, an unidentified “pirate” station came on the air in the Falklands. If you’re old enough, you’ll remember that the Brits ruled the Rock ’n’ Roll World in the 80s. The British pirate station was booming out the latest and greatest from the Rock scene. The audience of the pirate station, naturally, was the young draftees that made up most of the Argentine military forces in and around the Falkland Islands. Being south of the equator, the Falklands in April are in the middle of winter. The average ill-equipped, ill-trained, and ill-fed Argentine soldier, like most draftees away from home and at the end of the Earth, wasn’t a real happy camper.
Argentine radio from home was putting out some
pretty staid and conservative formatting that was approved of by the
government. The British pirate station was light-years ahead and took the
young audience away very quickly. In between the hits were lines like
“Eduardo, your Mother is praying for you,” “Tomas, your girlfriend misses
you!”, “Juan, your wife says the children are sick.” There is no evidence
that Eduardo, Tomas, or Juan threw their rifles away, but the British did
win back the Falkland Islands in 46 days of combat or 74 days total.
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Many of you are probably asking yourselves, “How can I land a high paying job in electronics?” (hereinafter referred to as an HPJIE). Okay, maybe one or two of you are asking yourselves that, or you’ve at least thought of it in the last few weeks. There are several paths to that end, to landing an HPJIE. My way was a rather indirect route, which I would not recommend to many people, unless they are presently selling appliances—make that vacuum cleaners—and are looking to better their lot in life. If that’s not you, I’d recommend you talk to Joe Maurus, our friend in Pumpkin Center, Louisiana, who seems to have gone about it the right way—and gets to be a public servant/first responder at the same time. It’s true: I once did sell vacuum cleaners. Not door-to-door (how I thank my lucky stars) but wholesale, to stores that would then sell them to you, the consumers. It didn’t take long to realize that vacuum cleaners sucked. I was looking to improve my lot in life, but had not yet met Joe (in fact, I’d never even heard of Pumpkin Center, Louisiana, back then), but I did have a friend who worked for a television transmitter manufacturer who suggested that I might do nicely selling those instead of vacuum cleaners. While I did have a ham license and experience as a Coast Guard radioman, I knew diddly about television transmitters and told him I couldn’t possibly sell something I was so unfamiliar with. “You’ll learn them in no time,” he assured me. Within a few days, I was introduced as “the new sales engineer.” I always thought that title was fine if I didn’t have to live up to it, having three credits in English and a ham license. My friend told me not to worry about it, that I’d know more than most of the people I was talking to.
Within a few days, I was shown how to predict
coverage of a television transmitter, given antenna gain, pattern, height,
terrain, and “effective radiated power,” a magical number of watts
available to those who subscribed to the Television Factbook. This
information and some ratings figures for the various stations told me what
counties they were doing poorly in, and then it was up to me to find
whether it was terrain that caused their problems, or the programs they
carried. I had no solution for programming.
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