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TUNING IN by Harold Ort, N2RLL Amateur—Just What Does It Mean? Pop’Comm writer Bob Sturtevant and I regularly talk about relevant radio topics (and some things not so relevant!), things I’m sure you’re also thinking and talking about from time to time. Over the years, I’ve found that relying on other folks’ professional opinions to be invaluable. The topic of how the general public perceives radio enthusiasts recently came up, along with what we might do to improve that image…if indeed it needs improvement. In some cases, I think it does. Bob brought up some good points about “amateur radio,” for example, saying, “Does the name ‘amateur’ reduce our value in the eyes of those we interact with in a public service way? Does this cause a reduction in our effectiveness because of this reduced value in their estimation? What can we do about it? Is there such a thing as a professional amateur?” Good points, don’t you think? In a world gone mad, where frequently what we see in real-world America on TV and read in the paper is more “reality” than those so-called reality TV programs, there should—must—come a point when we collectively sit back and examine where we’re headed. That goes for within our homes, our schools, inside the Beltway, and even within the many facets of our radio hobby. It’s no secret that the general public frequently thinks of scanner users as snoops, voyeurs, cop wanna-bees, and criminals. CBers are simply all truckers, or simply out-of-touch with reality. And hams, well, hams are those older folks with the radios who help out during disasters. But whatever hams are in the public mind, for better or worse, we’re still stuck with the term “amateur.”
The term “amateur” actually comes from the
word, “amatore” or “to love.” And that we do; we love our radios,
experimenting, talking around the world, and using new technology to
further our understanding of the many aspects of radio. In general, we
love being an integral part of our community in times of need while
enjoying the fun aspects of our hobby. We can’t be called “professionals”
because that term would indicate that folks get paid for their services,
and by law, amateurs cannot.
To read the entire article, subscribe to INFOCENTRAL
News, Trends, And Short
Takes by Harold Ort, N2RLL, Editor, and D. Prabakaran Radio Station HCJB, the Voice of the Andes, aired its final English-language broadcasts on international shortwave radio from Ecuador on Saturday, May 6, even as the station’s English Language Service shifts its emphasis toward teaching English as a second language. English was one of the first two languages, along with Spanish, to air when the station began broadcasting in Quito on Christmas Day, 1931. To accommodate new international airport construction near the capital city of Quito, missionary engineers and national staff have lowered a two-antenna curtain array. And in 2003 the mission switched to local and regional AM and FM broadcasts in these regions while refocusing its Ecuador-based international shortwave outreach on Latin America.
Mission leadership has determined that the
station will not risk potential radio interference to future air traffic
communications once commercial flights begin. Barring unforeseen
circumstances, all transmissions from the Pifo site (including Spanish,
Portuguese, German, Low German, English, and various indigenous languages,
including Quichua) are expected to end sometime in 2009.
A 100-kW transmitter has already been shipped
from Pifo to HCJB World Radio-Australia’s shortwave site at Kununurra.
That facility began transmissions in mostly Asian languages (in addition
to English) in January 2003. Ten shortwave transmitters remain in Ecuador.
The international transmitter site was later moved to Pifo in the early
1950s. Four of those transmitters were designed and built at the HCJB
World Radio Engineering Center in Elkhart, Indiana, including a powerful
500,000-watt unit.
To read the entire article, subscribe to Miles Of Smiles A Dozen Must-Know Mobile Radio Installation Tips by Harold Ort, N2RLL It’s summertime and the drivin’ is easy—except for those gas prices, of course—and you’re ready to embark on a journey. Your bags are packed and you’re ready to go, scanners and all, when you suddenly realize you’re out of duct tape and your brother-in-law “borrowed” your last two bungee cords for his bicycle. Not to worry, though. You’re thinking you can always temporarily fasten that new handheld just above the glove compartment on the passenger airbag portion of the dashboard using some double-stick tape you got at the office superstore. After all, you’re only going 100 miles and might be thinking that odds are the airbag won’t deploy. Yeah, right. You probably also thought it would never cost you more than 50 bucks to fill your tank! Personally, I wouldn’t take those odds to any bank, and you’re crazy if you do. But the fact is, I’ve seen some pretty crazy mobile radio installations that can even be deadly. All it takes is a few “accidental” circumstances to occur and that improperly mounted radio becomes a deadly projectile.
It doesn’t have to be that way; scanners and
other mobile radios don’t have to be mounted—even temporarily—like we’re
living in the Dark Ages. Let’s take a look at how to mount that scanner in
your vehicle so you’re able to actually use the radio (what a novel
thought!) and your hobby won’t injure or kill yourself or a passenger.
To read the entire article, subscribe to SCANTECH Managing Frequency Information 101 by Ken Reiss Last month we took a look at finding new frequencies, and I mentioned that you should keep track of the frequencies that you know about so you can spot gaps in your knowledge. Just by coincidence, I got an e-mail from reader Jack in St. Louis who was looking for suggestions on how to keep track of all the information he was beginning to collect. So let’s take a look at some easy, and some not so easy, ways to keep all this straight. Keeping track of frequency data, or more precisely user data, is really about half the game with scanning. Who’s using what frequency and for what purpose? And in what memory position in which radio did I store that? The better job you do of keeping track of this essential information, the better you’ll be able to program your scanner, and the more likely you’ll be able to reprogram your radio when necessary to follow a major event. For the record, the absolute worst thing you can do is just program your radio without keeping any notes. Sooner or later, the power will fail or something will get corrupted and you’ll have no data from which to reprogram the radio. Most of us manage to keep this information. The question is how and where. At the most basic level, a disorganized mess of notes and lists that other folks may have given us over time gets collected someplace. It’s not pretty, but a lot of us have operated that way for a long time. Sooner or later, probably at a time when you need to reprogram your scanner in a hurry, this system gets to you.
Perhaps the easiest system to get all of this
organized is the good old fashioned three-ring binder. It’s a tremendous
leap forward over the lose-notes system, but it still can offer some
challenges in finding information in a hurry. Most people I know organize
their binders either by frequency or by the agencies they’re interested in
listening to. If you have a word processor to help you sort and reprint
the information in several different forms, it can be extremely helpful.
To read the entire article, subscribe to
The National Registry Of
Certified by Rich Arland, K7SZ The National Registry of Certified EmComm Volunteers (NRCEV) is a term that Emergency Communications (EmComm) volunteers are going to become very familiar with over the next few years. NRCEV is the brainchild of several dedicated EmComm volunteers in Snyder County, Pennsylvania. Chris Snyder, NG3F, and others are the prime movers in the endeavor to form a private organization that will test, certify, and maintain a standardized registry of emergency communicators on a nationwide basis. Their mission: to structure a private certification organization that will certify EmComm volunteers, Amateur Radio Communications Teams (ARCTs), and EmComm organizations in the basic and advanced areas of providing communications during emergencies and disasters.
The ultimate goal of the NRCEV will be for
their certification process to be recognized on a national level by the
Federal Emergency Management Agency (FEMA) and the Department of Homeland
Security (DHS), along with all state and local governmental agencies,
Volunteer Organizations Active in Disasters (VOAD) members and the amateur
radio community. The days of the amateur radio operator grabbing his or her handheld VHF/UHF radio and a handful of batteries and running out the door to provide emergency communications during a disaster are over. Period! The name of the game in the post-9/11 era of disaster mitigation is “certification.” Just owning a truckload of sophisticated communications gear and participating in the American Radio Relay League’s (ARRL) annual Field Day exercise the last weekend in June and the annual Simulated Emergency Test (SET) each fall is not enough. Today’s EmComm volunteers need specialized training. They need to know the operations of the Incident Command System (ICS), the National Incident Management System (NIMS), the National Response Plan (NRP), as well as basic and advanced communications procedures, stress management techniques, how to allocate communications resources, and work with volunteers. And the list goes on.
To read the entire article, subscribe to V.I.P. SPOTLIGHT Our August Winner:
Brian Limbach of Pop’Comm reader Brian Limbach tells us, I have been a shortwave listener for 32 years! Several receivers have been used during that time. I started in 1973 using a 4-10 mc portable shortwave receiver. There was no BFO, so sideband reception was not possible. However, I got my first taste of international broadcasting listening to the BBC, Peking, China, and WWV, which were my first stations heard. My next receiver was a Heathkit SW-717, which my brother built for me in December 1973. International broadcast, some amateur radio station reception, and CB were received.
The Drake 2-C communications receiver arrived
in June 1974. It was a birthday gift purchased from Tydings Radio in
Pittsburgh. Much better reception of all modes could be had now, with
Luxembourg, South Africa, and Vietnam received for the first time, along
with stations in USB and LSB, including ham contest operations. I even got
my first receptions of slow scan television on 14.230. Unfortunately I did
not—and still don’t—have the monitor with which to see their
transmissions. My latest receiver is a Kenwood R-5000 that I purchased in 1987. I have obtained several QSLs over the years, starting in 1973, with 53 total cards to date. Currently, I have 24 shortwave, 17 mediumwave, and 12 amateur radio contacts in my card collection. Maybe it’s not the number of cards others have, but I treasure them all. The Voice of America was the first one I obtained.
I have enjoyed this hobby, with the new
shortwave radio countries and exotic amateur radio operations I have heard
over these many years.
To read the entire article, subscribe to BROADCAST TECHNOLOGY Special: Outdoor Antennas That Will Guarantee You An Outstanding DX Season! by Bruce A. Conti It’s already August and summer will be over before you know it! However, mediumwave DXers look forward to this time of year as summer thunderstorm activity begins to subside. In addition, some of the best ionospheric conditions of the entire year for long-distance mediumwave reception occur as early as mid-August and continue through the autumnal equinox into November.
With the bottom of Solar Cycle 23 in progress,
it should be an exceptional season for transcontinental and transoceanic
mediumwave DX. Don’t miss out on the action! Be prepared with these
easy-to-build outdoor wire antennas, guaranteed to improve reception. Admit it. Most, if not all, beginner AM broadcast DXers, mediumwave and shortwave, have tried this “antenna.” Hang a random length of wire out the window of your radio shack and connect it directly to a receiver. While there might actually be some degree of improved reception with such a simple outdoor antenna, in reality it’s probably the worst thing you can do. With so many sources of radio-frequency (RF) emissions in households today, radiating from televisions, computers, lighting, kitchen appliances, electrical wiring, etc., the “wire out the window” approach will not only improve broadcast signal strength, but it will also substantially increase noise pick-up. A noise-reduced lead-in consisting of coaxial cable and an RF matching transformer is crucial for successful implementation of any outdoor wire receiving antenna. Without it, many weak signals will be missed, buried under RF noise, eventually resulting in one discouraged DXer.
Secondly, the outdoor wire antenna itself
should be located in an RF quiet position. Try to find a location away
from overhead electric power and utility cables, and not too close to
buildings and buried cables. Use a portable receiver to survey potential
locations. Tune to locally empty frequencies at the low and high end of
the AM broadcast band to check noise levels. Begin with testing for noise
pick-up by placing the receiver close to where the electric power mains
enter your house or close to a utility pole; the high noise level should
be obvious.
To read the entire article, subscribe to THE POP’COMM TRIVIA CORNER Radio Fun And Going Back In Time by R.B. Sturtevant, KD7KTS Q. What’s changing at RadioShack? A. RadioShack started as a Boston-based mail order business in 1921. Its primary customers were ham radio operators and electrical experimenters. It issued its first catalog in 1940. In 1954, it brought out products under the Realistic brand name. By the early 1960s, it was practically bankrupt. In 1963 the Tandy Leather Company bought it out when Charles Tandy wanted to build a chain of leather craft and hobby stores. Tandy began by collecting almost $800,000 owed to the company, expanded the chain with quick turnover items, and pumped nine percent of the sales revenue into advertising. Between 1961 and 1969 the sales grew from $16 million to $180 million. In 1968 there were 172 Radio Shack stores and in 1973 Tandy had grown the company to 2,294 stores. When the CB craze hit three years later, sales were up 125 percent and another 1,200 stores opened. Anyone looking at radio magazines from that period knows that building articles included parts lists with their RadioShack part numbers already supplied. It was also the first to bring out a mass-marketed personal computer. Charles Tandy died in 1978. A year later there were 7,353 RadioShack stores and only 5,530 McDonald’s restaurants. RadioShack seems to have changed its direction since it’s decided to get out of the electronic parts business, and the stores have almost stopped carrying ham gear. In fact, I once said to a RadioShack manager, “I am a ham radio operator and I’d like to buy a key.” I was directed to a nearby hardware store and told, “They make them up for you while you wait.” Q. During World War II how did the military and civilian authorities find enough radio operators to do all the communications that was needed? A. It was a serious problem. Six months after the war started, the military was buying more radio equipment then they ever had before. Training radio operators in CW, which was the most common mode of transmission, takes time. Finding operators who could handle high-speed traffic (40 wpm or more) was even harder. Civilian organizations had similar problems. The natural place to find skilled operators and instructors to train the newcomers was among the ham operators who had been taken off the air when war was declared.
The Amateur Radio Rely League (ARRL) set up a
Personnel Bureau to assist government agencies and the military find the
operators they needed. They even assisted in finding personnel for secret
and top secret programs being started.
To read the entire article, subscribe to MILITARY RADIO MONITORING ON VHF, UHF, HF, AND SATELLITES Listening Is Easy—Here’s Where To Catch Those Military Comms! by Tom Swisher, WA8PYR
Have you ever wondered what kind of
military/government transmissions are out there to listen to? Here’s a
basic primer of the bands to monitor and what you might hear. Hang on to
your hats, you might be surprised!
Starting off at the bottom of the spectrum are
the very low frequency (VLF, 10 kHz–30 kHz), low frequency (LF, 30 kHz–300
kHz), and medium frequency (MF, 300 kHz–3 MHz) bands. These bands don’t
hold much for the average listener, but there is activity there. In
addition to the AM broadcast band, various navies use the VLF band to pass
alert messages to submerged submarines. Also found here is air navigation
beacons, as well as VLF propagation beacons which will give you an idea of
band conditions. Often overlooked, yet a fairly simple band to monitor is the high frequency band, from 3 to 30 MHz. Often used by military and government agencies all over the globe, it’s fun to monitor as you can hear transmissions from every part of the world, depending on the frequency and band conditions at the time. Covering the frequencies from 3 to 30 MHz (the portion from 28 to 30 MHz is often thought to be part of the VHF band, but it’s actually the upper end of the HF band), it’s action on steroids! The most popular monitoring target for newcomers (besides shortwave broadcast) is the high frequency Global Communications System. Known under a variety of names over the years, the HF-GCS is also known as GHFS, for the Global High Frequency System. This is a worldwide U.S. Air Force communications system created during the 1950s during the watch of Air Force Chief of Staff General Curtis LeMay, who as a ham radio operator knew well the capabilities of HF radio for long-distance flights.
But there’s more to HF than just HF-GCS.
Another interesting monitoring target is SHARES (SHAred RESources). Part
of the National Communications System, SHARES is a program for sharing
frequencies allocated to federal agencies. SHARES provides agencies with
extended HF coverage and capabilities and a survivable backup
communications system that can help take the place of leased lines and
satellite systems in the
To read the entire article, subscribe to RADIO RESOURCES Automatic Identification System For MURS! by Gordon West, WB6NOA The U.S. Coast Guard says “e-navigation” means safety for all boaters, and the Automatic Identification System (AIS) is the latest and greatest (relatively) new VHF service to help achieve that goal. AIS is used for ship-to-ship and ship-to-shore identification and tracking, and offers a brand new twist for the Multi-use Radio Service (MURS) land-on-land position fixing. AIS is a marine radio broadcast system that acts like a transponder, receiving GPS information and transmitting on marine VHF duplex shore channels 87B and 88B (161.975 and 162.025 MHz). These two international marine shore station duplex channels carry 9,600 bits/s data. If you live near a seaport, you’ll hear is a one-second data burst every few seconds coming from commercial ships, towboats, and ferries within 30 miles of your outside scanner antenna. The data will sound somewhat “pinched” because your receiver’s filters and de-emphasis circuits lop off a portion of the incoming data burst. The dedicated AIS receiver picks the signal off the discriminator and processes the entire 25-kHz data bandwidth.
The two-channel AIS dedicated receiver, which
is not much larger than a big handheld radio, processes the 9600 bits/s
GMSK (Gaussian Minimum Shift Keying) FM using HDLC (High-level Data Link)
packet protocols. If you’re using a communications receiver capable of
passing a wide FM signal to your computer sound card, software alone could
allow you to decode one channel of AIS information. Most of the time, one
channel of reception is all that’s necessary to decode exciting vessel
traffic in your area, much like aircraft controllers tracking aircraft in
the sky.
To read the entire article, subscribe to TECH SHOWCASE Pro Tech’s NoiseBuster NB-FX Active Noise Reduction Headphones by Harold Ort, N2RLL, Editor Headphones of all sizes, colors, and weights are everywhere. And they all come with a price tag, sometimes costing nearly as much as our scanners or amateur HTs. I’m talking $299 for headphones! If you think that’s a hefty sum for headphones, regardless of the great sound you get, join me for a moment as we check out a $69 pair of headphones from Pro Tech: the NoiseBuster.
The company tells us that, “NoiseBuster
contains patented ANR technology…and delivers 18dB of active noise
reduction across a wider frequency range than any competitive consumer
audio headphone available on the market today.” That’s certainly a pretty
lofty claim, so we decided to check it out with the equipment we use most,
in an environment that has its share of noise—using a handheld scanner in
the local mall. Just wearing these headphones is a pleasure; the soft ear pads fit comfortably and the headband doesn’t smash the ear pads against your head. There’s nothing worse than good headphones that don’t fit properly, and these fit perfectly!
The NoiseBuster headphone comes with a
standard 3.5-mm stereo plug at the end of a four-foot straight black cord.
A single “AAA” battery that’s included powers the headphones. A simple
slide switch on one earpiece turns them on/off and a small red light lets
you know they’re powered. When you’re finished for the day, tuck them in
the provided pouch. Travel on the plane with them and you’ll be able to
use the included airline adapter plug!
Here’s the scoop: On the inside and outside of
each ear cup is a small microphone used to capture noise. Inside, that
junk noise is used to create, as NoiseBuster says, “…a noise wave that is
identical to, but directly opposite of, the one coming into the ear. The
‘anti-noise’ wave is output through a speaker located in the ear cup. When
the two waves (the offending noise wave and the anti-noise wave) meet, the
noise is significantly reduced.”
To read the entire article, subscribe to
Capitol Hill And FCC Actions
Affecting Communications by Richard Fisher, KI6SN The FCC will be required “to conduct a study of the interference potential of broadband over power lines (BPL) on amateur radio and first responder radio communications systems” within 90 days after legislation designated the Communications Opportunity, Promotion and Enhancement (COPE) Act becomes law. The directive came in an amendment in April to a bill drafted by the U.S. House of Representatives Committee on Energy and Commerce. With unanimous committee support, the amendment “would guarantee that valuable public safety communications and amateur radio operators are not subject to interference and ensure that the service provided by over 600,000 amateur radio operators and many more first responders are protected,” U.S. Rep. Mike Ross (D-Ark.) said in a statement. He proposed the amendment calling for the study. “This puts the House Energy and Commerce Committee on record as having concerns about BPL interference,” American Radio Relay League CEO David Sumner, K1ZZ, said. “If we are vigilant in protecting it against deletion on the House floor—assuming the bill is approved by the House—the BPL language will be included in the legislation that goes on to the Senate.” “In today’s evolving world, technological advancements are being made at a previously unimaginable pace,” Ross said. “The Telecommunications Act of 1996 is outdated and must be revised to reflect today’s rapidly evolving needs.” Ross continued that, “technological change is driving the convergence of a number of previously distinct telecommunications and media markets. Digital technologies are being deployed in and carried over wire line, cable, and wireless networks that are increasingly capable of providing voice, data, and video services over a single broadband platform.
“By streamlining the franchising process, the
COPE Act will bring more products, options and competition thereby
reducing cost to consumers. As the highest-value telecommunications
service, video is the driving force of infrastructure development. More
infrastructure is desperately needed in the 150 small towns I represent. A
national franchise agreement will enable rural Americans to have access to
the latest technology,” said Ross.
To read the entire article, subscribe to PLANE SENSE
The Air Traffic Control
Position With by Bill Hoefer
Anyone who’s followed my column over the last
five years will notice I’m a little eclectic in my pursuits. I’ll quote
odd authors and movies, and even try to throw in a little Star Trek.
(Watch me quote from an ST film later.)
In 1951 the legendary George Pal produced the
film When Worlds Collide for Paramount. There are only a couple of flying
scenes, the first within two minutes of the opening credits when the hero
of the film, Dave Randall, played by Richard Derr, was making out with an
unnamed female in what appears to be an old Bellanca. He gives his name to
the control tower operator (who also gives his name) and all but ignores
the command of the controller. The film only shows just a bit of ATC, but
it’s clearly a poor rendition of even early 1950s control. It’s currently
in the lead for the next BARTCC SAVAGE award.
To read the entire article, subscribe to THE PROPAGATION CORNER Propagation Model Reliability by Tomas Hood, NW7US In previous months, we’ve explored the commonly asked question, “When will good propagation occur?” That simple question has a difficult answer, so difficult in fact that powerful computer models are required to predict when HF circuits are likely to connect. And when various system variables are added, such as frequency, transmitter power level, antenna gains, and sunspot numbers, the problem becomes difficult indeed. Last month, we discussed how HF propagation models use statistics to determine the reliability, or time availability, of a given circuit. Most models create circuit predictions for monthly intervals, and then find the reliability of the prediction in terms of the days of the month when that condition can be expected to prevail. For example, when the user specifies a 50-percent required reliability, then the prediction is for 15 days out of a 30-day month, or better. If the user specifies 90-percent reliability, then the resulting predictions will be as shown, or better, during 27 days of the month. The model uses its statistical database to produce more accurate, and more conservative, predictions as the specified reliability level is increased.
This month, we will explore the history of the
popular VOACAP model and will show how the SWL enthusiast or ham radio
operator can use new tools to make his or her predictions agree more
closely with on-air experiences.
HF propagation models had a long history of
development, going back to the U.S. Army’s Ionospheric Radio Propagation
Technical Report #9, published by the National Bureau of Standards in
1948. The Institute for Telecommunication Sciences and Aeronomy released
the first computer prediction program, called ITSA-1, in 1966. A second
generation of ionospheric prediction programs, known as ITS-78 or
sometimes HFMUFES-4, was developed in 1969. This led to continued work by
the National Telecommunications and Information Administration’s Institute
for Telecommunication Sciences (ITS), and the well-known IONCAP model—the
third generation of HF predictions programs—was eventually released to the
public.
To read the entire article, subscribe to HAM DISCOVERIES Radiosporting—That’s A Sport? by Kirk Kleinschmidt, NTØZ
In Russia—and the extreme parts of
Scandinavia—darn near everything’s a sport. For example, some adventurous
souls take perfectly good dirt bikes, twist a few hundred sheet metal
screws into the tire treads and race on frozen lakes at 100 mph. For even
more excitement the riders may opt to play “polo” by adding sticks and a
ball, plus the occasional spectacular collision. And I’m sure that’s not
the worst of it! Our drive to compete will always find expression. In Russia, in keeping with this month’s impromptu theme, they call ham radio competition “Radiosporting.” Actually, they call it that in many parts of Europe that don’t necessarily see ice-racing dirt bikes. In that neck of the woods you can train hard, become famous, and even become state-sponsored by winning amateur radio on-air contests! You can become famous (or infamous) here in the United States, but you can almost certainly forget about being honored as a champion by the state. So, what’s up with ham radio competitions, anyway? To get started, let’s get a few definitions out of the way. Radio contests are usually on-air events in which hams work as many different stations as possible in a defined period of time, often a weekend. Depending on the particular contest, a premium is placed on working stations in different geographical regions (states, countries, ARRL sections, CQ magazine zones, grid squares, islands, and so on) or stations with different callsign prefixes (KA2AAA, KB2AAA, KC2AAA, and so on). These geographical regions or differing prefixes are called “multipliers.” In the simplest sense, contest scores are determined by multiplying the number of two-way contacts (QSOs) by the number of multipliers, subject to the fine points of each particular contest, of course!
When the dust settles, the contestants with
the highest scores (there are usually several categories of competition,
such as power level, number of station operators, and bands used) receive
certificates or plaques and have their scores listed in CQ, QST, and other
ham magazines.
To read the entire article, subscribe to RADIO RESOURCES Automatic Identification System For MURS! by Gordon West, WB6NOA The U.S. Coast Guard says “e-navigation” means safety for all boaters, and the Automatic Identification System (AIS) is the latest and greatest (relatively) new VHF service to help achieve that goal. AIS is used for ship-to-ship and ship-to-shore identification and tracking, and offers a brand new twist for the Multi-use Radio Service (MURS) land-on-land position fixing. AIS is a marine radio broadcast system that acts like a transponder, receiving GPS information and transmitting on marine VHF duplex shore channels 87B and 88B (161.975 and 162.025 MHz). These two international marine shore station duplex channels carry 9,600 bits/s data. If you live near a seaport, you’ll hear is a one-second data burst every few seconds coming from commercial ships, towboats, and ferries within 30 miles of your outside scanner antenna. The data will sound somewhat “pinched” because your receiver’s filters and de-emphasis circuits lop off a portion of the incoming data burst. The dedicated AIS receiver picks the signal off the discriminator and processes the entire 25-kHz data bandwidth.
The two-channel AIS dedicated receiver, which
is not much larger than a big handheld radio, processes the 9600 bits/s
GMSK (Gaussian Minimum Shift Keying) FM using HDLC (High-level Data Link)
packet protocols. If you’re using a communications receiver capable of
passing a wide FM signal to your computer sound card, software alone could
allow you to decode one channel of AIS information. Most of the time, one
channel of reception is all that’s necessary to decode exciting vessel
traffic in your area, much like aircraft controllers tracking aircraft in
the sky.
To read the entire article, subscribe to TECH SHOWCASE
Pro Tech’s NoiseBuster NB-FX by Harold Ort, N2RLL, Editor Headphones of all sizes, colors, and weights are everywhere. And they all come with a price tag, sometimes costing nearly as much as our scanners or amateur HTs. I’m talking $299 for headphones! If you think that’s a hefty sum for headphones, regardless of the great sound you get, join me for a moment as we check out a $69 pair of headphones from Pro Tech: the NoiseBuster.
The company tells us that, “NoiseBuster
contains patented ANR technology…and delivers 18dB of active noise
reduction across a wider frequency range than any competitive consumer
audio headphone available on the market today.” That’s certainly a pretty
lofty claim, so we decided to check it out with the equipment we use most,
in an environment that has its share of noise—using a handheld scanner in
the local mall. Just wearing these headphones is a pleasure; the soft ear pads fit comfortably and the headband doesn’t smash the ear pads against your head. There’s nothing worse than good headphones that don’t fit properly, and these fit perfectly!
The NoiseBuster headphone comes with a
standard 3.5-mm stereo plug at the end of a four-foot straight black cord.
A single “AAA” battery that’s included powers the headphones. A simple
slide switch on one earpiece turns them on/off and a small red light lets
you know they’re powered. When you’re finished for the day, tuck them in
the provided pouch. Travel on the plane with them and you’ll be able to
use the included airline adapter plug!
Here’s the scoop: On the inside and outside of
each ear cup is a small microphone used to capture noise. Inside, that
junk noise is used to create, as NoiseBuster says, “…a noise wave that is
identical to, but directly opposite of, the one coming into the ear. The
‘anti-noise’ wave is output through a speaker located in the ear cup. When
the two waves (the offending noise wave and the anti-noise wave) meet, the
noise is significantly reduced.”
To read the entire article, subscribe to COMPUTER–ASSISTED RADIO MONITORING Digital Signal Processing—Part IV by Joe Cooper Wrapping Up Our Exploration Of Digital Sampling Technology Over the past series of columns we’ve learned that digital technology is not something new. The “digital revolution” has actually been in development for just over 300 years. More importantly, you now know that the “ancestor” of any digital technology that may you own—CD player, cell phone, digital signal processing (DSP)-based radio, or even a micro-computer—was a telegraph key. All of today’s digital technology can be traced back to the first practical telegraphy system developed by Claude Chappe in France in 1792. And the first true application of DSP was when Baron Pavel Lvovitch Schilling began transmitting telegraph signals in 1832 using electrical wires. Even those critical improvements made in telegraphic technology, such as American scientist Joseph Henry developing the mechanical striker, were simply further applications of DSP technology. One could even argue that when Samuel Morse developed his alphanumeric code to exploit the commercial potential of Henry’s mechanical striker he developed the human equivalent of a computer software program to encode and decode a message.
Telegraphy, whether visual, over wires, or
wireless, has always worked exceptionally well as a method of
communication, so much so that the radio engineering community of the
early 20th Century agreed that a method was needed to allow voice and data
communications to be transmitted in digital form.
When early attempts were made at analog voice
communication, the techniques first used were already obsolete. The carbon
microphone used in the first successful voice broadcast by Reginald
Fessenden in 1906 was already a relic of 18th Century technology. However,
despite the limitations involved the exciting potential for the
communication of voice and music motivated amateur radio experimenter to
use whatever was on hand. What most hams used when attempting early voice
communication was the carbon microphone, which was relatively cheap and
easy to find. These early amateur-built radios and transmitters were
crude, even by the standards of the day, but they worked.
To read the entire article, subscribe to UTILITY COMMUNICATIONS DIGEST We’re Back! MARS Changes, The Death Of WUN, And Coming Attractions by John Kasupski, KC2HMZ As followers of this column undoubtedly noticed, “Utility Communications Digest” has been on a “summer vacation” for the past two months. I won’t bore you with all the specifics about why this occurred, but I’m happy to say that the column is now open again under new management, beginning with the issue that you’re now holding. As I begin my stewardship of this long-running Pop’Comm column, I’d like to take the opportunity to encourage you to begin or continue, as appropriate, to send in your contributions in the form of loggings, shack photos, and stories about your own utility communications listening experiences.
Although I’ve been a contributor to a couple
of the monthly columns, including this one, on various occasions in the
past, this will be my first experience at writing a monthly column for
this magazine. I’ve always felt that it’s best to just jump right in and
get started, so let’s begin with a look at a some news items that have
accumulated while we’ve all been trying to figure out new ways to get rid
of the static in our radios caused by the neighbor’s old, inefficient, but
unfortunately still working air conditioner!
As this month’s column was being written, word
was received that several units from the U.S. Navy’s USS George Washington
(CVN 73) Strike Group were operating with the U.S. Coast Guard and various
other forces from the Caribbean and Latin America area as part of the
Partnership of the Americas. Among them was the guided missile frigate USS
Underwood (FFG 36), which also participated in ongoing operations in the
western Caribbean aimed at stopping illegal drugs from reaching the United
States.
To read the entire article, subscribe to GLOBAL INFORMATION GUIDE HCJB Ends English Shortwave by Gerry L. Dexter By the time you read this HCJB will have ended all of its English language programming, including the fabled “DX Party Line,” which lingered for a while in other services and on other stations after the North American service was killed off a couple of years ago. DXPL had been on the air continuously since 1961, and its loss has to be counted as another large step downward in the slow decline of what was once one of the world’s mightiest and most appreciated shortwave broadcasters. Just so you really get the point, late word from HCJB is that deconstruction has begun on the towers at their Pifo, Ecuador, transmitter site, so the loss of some HCJB frequencies has already begun. That special Radio Japan “Shiokaze” service aimed at Japanese individuals kidnapped by North Koreans has been extended. It now airs from 1400 to 1500, repeated at 1900, both on 5890. In addition to programming in Japanese, the expansion includes some English and Korean, as well. So far, the service has received reports from a number of different countries, but has had no reaction from the people they are trying to reach. That’s hardly surprising since those people are probably in no position to mail letters. Once the winter months return again we should have a better chance to hear this one. If your listening travels have ever taken you into the 60-meter band, you’ve likely run into the “blip, blip, blip” sounds that appear from around 4750 up to 5 MHz. Known as “CODAR” (coastal ocean radar), the signals are used to measure the height of ocean waves. The interference they create makes them almost as annoying as that guy in the Ditech TV commercials! We need to warn you that there are more of these things on the way. Our friendly, all-knowing, ever helpful FCC has authorized additional such transmitters based at various universities and oceanographic institutions along the Florida and California coasts. They’ll be using 4470, 4550, 4800, 4900, 12060, 12140, 12200, 13460, 13630, and 13700. Yikes!
Every now and then significant shortwave news
seems to appear from out of nowhere. “John Madden!” (i.e., “boom!”)—a new
signal appears that no one had any idea was coming. That occurred recently
when DXers began encountering Radio Internacional de Chile in the 31-meter
band. Several years ago then-Radio Nacional de Chile closed and later sold
its transmitters to Florida-based Christian Voice, which uses them for its
Voz Cristiana broadcasts. It turns out that the new Chilean broadcaster
is, in fact, simply a relay through the facilities of Radio Nacional
Amazonia in Brazil. It’s being reported on 9665 around 0300 and later. It
could be that, early on, these are just experimental, as our checks
haven’t found anything.
To read the entire article, subscribe to SHANNON’S BROADCAST CLASSICS A Girl And Her T-Bird Radios Plus A Guest Drops By by Shannon Huniwell with Guest Columnist, Carl Tyrie
Mom noticed it on the little table next to my
bed and went straight to my father. Eavesdropping through the tightly
closed door of their room, I overheard Dad gently assure her that I was
old enough to know how to safely use such a thing. Before anyone jumps to conclusions, I should note that “it” was a bare chassis tube radio from an old Ford Thunderbird. Dad had pulled the darn thing out of an early ’60s T-bird that was rusting away in a local junkyard. He enlivened the unit’s small tubes with a $19.99 Micronta-Radio Shack 12-volt regulated power supply that, as Dad liked to point out, cost nearly 20 times what he’d paid the junkman for the hefty AM car radio. My folks compromised on the “danger of electrical shock” issue, which meant that Dad offered to build a cabinet for the radio and mom gave him an approving kiss. This détente resulted in a nicely sanded pine cube in which the receiver, power supply, and five-inch oval speaker were regally garaged. Groupings of quarter-inch holes allowed tube heat and sound to escape in sufficient quantities. For fun, my father sopped up a bit of Minwax Fruitwood stain for a finish, and topped off the project with a Powered by Thunderbird emblem scrounged from the aforementioned auto graveyard. A “T” long-wire strung between poplar trees served as the radio’s antenna, and gave it amazing “DX-ability.” But what I remember best is the slide rule dial’s glow in the middle of the night. Adventures in music, talk, and geography existed between the tiny civil defense triangles near the beginning and end of that fascinating numerical row. With eyes closed, I can vividly recall the heterodyne whistles, cross-talk, and fading of the 1970’s AM band; to me, all mysterious and possessing the possibility that some never-before heard signal would suddenly connect my little world to somebody broadcasting in an equally small room maybe several thousand miles away.
LOOSE CONNECTION Back On The Farm… by Bill Price, N3AVY Norm showed up last weekend to give me some radio things and help me put up the antenna that would assure us of eternally free long distance communication, forever and ever, amen. Like e-mail, only with static. And fade. My landlord is perhaps the most easygoing person this side of the Mississippi. It seems that no matter what I want to do, his answer is, “Sure, just don’t hurt anything.” That included my request to fasten the antenna to a concrete silo and a huge oak tree. There were no remaining climbing rungs on the silo, and we sure didn’t have any 50-foot extension ladders or anything close to it. My substantial girth prevented me from even thinking about any means of climbing or scaling the wall, no matter what type of ropes, pulleys, or even winches were involved. While I have no fear of heights—but weigh too much—Norm is wiry but doesn’t care for scary altitudes, so we mixed up some lemonade and pondered the situation from a couple of lawn chairs. As much as I love my guns, I don’t think there’s a safe, sane, or effective way to connect a piece of fishing line to a bullet and fire it up to some high place and “thread the needle” with the fishing line so that you can then haul up a heavier piece of line and eventually pull up your antenna wire, and it’s one of the few things that neither Norm nor I will even try to design. Even we know it’s too dangerous and risky. That left us with: 1. a crossbow 2. a regular bow and arrow
3. a slingshot The only crossbow we could borrow took both of us to pull back and cock. That told us it would be way too dangerous for a couple of lunatics (“a man’s gotta know his limits”) like us to handle, so we borrowed a simple, ordinary bow (without all the pulleys, laser sights, v-6 engines, and steel cables) and bought a few target arrows and a spin-casting reel—a very cheap one which Norm asked if he could return if his nephew already had one. The man is really cheap.
When I was a wee lad, I was a fair shot with
bow and arrow. Richard Greene was playing Robin Hood on television (in
living black and white) and I was 10 or 12. Friends and I would shoot each
other with some pretty dangerous “safe tipped” wooden arrows. We could
have put our eyes out. Where were Ralphie’s parents and teachers to warn
us?
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