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To read the entire article, subscribe to NEWSWORTHY Unwired The Weirder Side Of Wireless
And The Winner Is…No. 962283
In a world gone celebrity crazy, it comes as a
breath of fresh (if not free) air. According to a BBC report, a
London-based prison radio station has received four nominations for the
prestigious Sony Radio Academy awards, pushing aside famous entertainment
hopefuls such as the hot-ticket comedian Russell Brand. The station,
Electric Radio Brixton, garnered a nomination for the Interview Award for
its piece with Jonathan Aitken, a former cabinet minister jailed for
perjury. It’s also up for awards in the Speech, Listener Participation,
and Community categories.
Tim Blackmore, chairman of the Sony Radio
Academy Awards, was quoted by the BBC as saying: “Every year we try to
adjust the categories to match the continual evolution of our industry and
this year’s entries have shown once again that alongside their heritage of
27 years, these awards remain truly contemporary.” In the interview,
Aitken, describes the fear he felt while “in the cage” at HM Prison
Belmarsh and discusses the physical threats he received, the report
continued.
To read the entire article, subscribe to NEWSWORTHY InfoCentral News, Trends, And Short Takes by D. Prabakaran
U.S. Psyops Seeks To Prevent Taliban Use Of Radio And Web The United States has started a broad effort in Pakistan and Afghanistan to prevent the Taliban from using radio stations and websites to intimidate civilians and plan attacks. U.S. military and intelligence personnel are attempting to jam unlicensed stations used by Taliban fighters in parts of Pakistan near the Afghan border. They are also trying to block Pakistani chat rooms and websites that frequently contain videos of attacks and inflammatory religious material that attempts to justify violent acts, according to a report by Reuters.
The push takes the administration deeper into
“psychological operations,” which try to influence how the United States,
its allies and enemies are seen, the report said, noting that officials
involved with the new program say such operations are a necessary part of
halting the deterioration of stability in Pakistan and Afghanistan. A new state-of-the-art DRM digital radio receiver was unveiled to DRM members at the annual general assembly of the Consortium being held in Erlangen, Germany, where the world’s two biggest broadcasting unions—EBU and ABU—reiterated their support to the DRM Consortium. The new DRM receiver is called Di-Wave 100 and has been developed by Uniwave Develop-ment SAS. This is the first DRM receiver with a color screen and was expected to be in mass production by April 2009. The receiver has all the multimedia features offered by DRM technology, including identification by station name, program information, and listening time shift.
The radio can receive DRM broadcasts on
shortwave, mediumwave, and longwave as well as analog FM, and can store
768 stations in memory. The receiver has a USB/SD card -reader and mp3/mp4
play-back. The 3.5-inch TFT color display can offer text in many different
languages.
To read the entire article, subscribe to NEWSWORTHY Washington Beat Capitol Hill And FCC Actions Affecting Communications by Richard Fisher, KI6SN
Nation’s Capitol To Get First Look At Free Mobile TV The first city in the United States to get digital TV broadcasts for cell phones, laptop computers, in-car entertainment systems and similar devices will be Washington D.C., it was announced in late April. Using new technology known as “mobile TV,” the free broadcasts were scheduled to begin in late summer and feature programming from local CBS, NBC, PBS and Ion affiliates, as well as a Fox-owned independent station, according to an Associated Press report. The Open Mobile Video Coalition—a group of companies backing the “mobile TV” technology—said the nation’s capitol was selected as a test market “because the city is full of tech-savvy viewers who pay attention to local news. Attention from politicians and regulators probably doesn’t hurt either,” the AP reported. “The coalition has earlier pointed to the usefulness of free mobile TV broadcasts in case of emergencies and disasters like hurricanes.” The broadcasts will be the same as those appearing on local television sets. The programming will also include the advertising.
By the end of 2009, “mobile TV” technology is
expected to be presented in dozens of other U.S. cities, including Boston,
Atlanta, New York, Chicago, San Francisco, and Philadelphia, and cover 39
percent of the nation’s households.
To read the entire article, subscribe to Newsworthy Horizons Communications And Privacy by Rob de Santos
At the Winter SWL Festival in Kulpsville, Pennsylvania (see “Come One, Come All…” pg. 26, February 2009, Pop’Comm) this past March, I shared some of my thoughts on the future of communications with the attendees. One issue came up over and over: privacy. Perhaps that shouldn’t be surprising. Given the audience and their unusually high degree of awareness of the changing horizons in communications, Fest attendees are probably more aware than the average person of the perils of progress. I’m sure many readers of this magazine are also aware of the challenges to privacy brought about by the advances we discuss in this column. The very nature of communications is at odds with privacy: effective communication requires information to be sent to someone or something somewhere else. From the dawn of communications itself, whether spoken or written, this has been a problem for those who wished to keep information between themselves and those they wanted to share it with. The obvious way to ensure privacy is encryption, which has been used since the days of the Greeks and Romans, and beyond, often for military purposes. Many readers will remember the panic in the mobile telephone industry in the late 1980s when it became known that early cellular phones could easily be monitored by hobbyists. The result was a bad piece of law known as the Electronic Communications Privacy Act (ECPA). Digital mobile devices and the encryption they allowed solved this problem, but the cellular bands remained off limits to hobbyists in the U.S., even though the law became mostly irrelevant (if it ever was). But privacy and technological advances in communications have always been marching side by side.
As an example, let’s consider one advance I’ve
discussed previously: cars that drive themselves on intelligent roadways.
To ensure that it reached its objective in a safe and timely manner, a
smart car on an intelligent road would have to identify itself in some
unique way and communicate its intended destination, speed, and current
location to a “controller” as well as to other nearby vehicles. Surely the
communications to controllers would be encoded in some fashion, but how
private would that data be? How easily could it be monitored (something of
more than incidental interest to the readers of this magazine)? Of course,
without any public roadway yet using this technology we can’t definitely
answer such questions, but we do need to pay attention as the technology
evolves.
To read the entire article, subscribe to
Summertime And The
Listening’s Easy— When It Comes To Scanning For Excitement, The Marine Radio Service Offers Plenty Of Opportunities To Catch “The Big One” by Gordon West, WB6NOA
Count on it: When the weather heats up, so
does the scanning action along the nation’s coast and inland waterways.
From 2 MHz to 470 MHz, marine radio channels are always active in the
summertime, so there’s plenty of opportunity for exciting listening. A new
petition by the Radio Technical Commission for Maritime Services (RTCM) to
the FCC could soon lead to marine radio use on land, too!
Before a marine SSB long-range radio may be
installed aboard any ship, that vessel must first have short-range VHF.
Recreational marine 25 watt VHF equipment no longer needs an FCC ship
station license, and marine VHF equipment prices can be almost
unbelievably low; for instance, you can get a 25 watt, all-channel marine
VHF for $129, and a pack of two marine VHF handhelds for under $99. So,
since a marine VHF transceiver is required equipment aboard all big boats,
is likely installed aboard pleasure boats, and is most people’s favorite
handheld radio to take along in canoes and kayaks, you have plenty of ways
to listen if you live within 20 miles of any water. And don’t fret if
you’re landlocked miles away from any water; we’ll talk about long-range
single sideband later, too. The marine VHF band is located just above 156.00 MHz, in 25 kHz steps, 5 kHz common deviation. In the late ’60s, marine VHF channels were subdivided from 50 kHz to 25 kHz steps, doubling the number of available channels. Currently, there are no firm dates to further subdivide the 25 kHz steps, nor any immediate plans for recreational and commercial radios to go narrow band at 2.5 kHz deviation. (However, the National Telecommunications and Information Administration, which governs the Coast Guard Auxiliary channels and other government channels, has mandated 2.5 kHz narrowband deviation.)
Allen Henney, co-founder and general editor of
the Capitol Hill Monitor (<www.henney.com/chm>)
and a Pop’Comm author, provided us with USCG Narrowband FM Special Use
Channels; see “CG Special-Use Frequencies (FM).” If you’re monitoring with a scanner or tunable PLL receiver, dial in the specific FM frequency; if you’re monitoring with a marine VHF radio, dial in the appropriate channel number.
Exciting distress calls can be heard on VHF
Channel 16, 156.80 MHz. Once the emergency situation becomes stabilized,
the US Coast Guard may switch the distressed boat over to VHF Channel 22A,
157.10 MHz. The “A” indicates an international duplex channel with U.S.
operation on the simplex transmit frequency. The duplex offset is 4.6 MHz
and higher; if a Coast Guard communications station switches a boater from
16 to 22A, but the boater only dials in Channel 22, their receiver is
offset 4.6 MHz up, and they will never hear the Coast Guard calling them!
To read the entire article, subscribe to THE LIGHTER SIDE Radio Fun Trivia And Toons by R.B. Sturtevant, AD7IL
Q. Are there any clues that can be given by radio to tell a spy organization that one of its agents has been arrested? A. In planning an operation that takes a spy into enemy territory, agencies instruct their operatives to make a specific mistake should they be captured and forced to transmit. For instance, they should always misspell the third and sixth word in their messages when sending code. That alerts the folks at home that they’ve been compromised. Another way is to watch the agents “fist,” that is, the way they send Morse code. Everyone sends CW slightly differently, just as everyone’s handwriting is different. To establish the rhythm and sound of their transmissions, recordings are made agents’ sending before they go on their mission. Then, if the enemy puts an agent in jail and substitutes another operator a good Intercept Operator, who knows the agent and know the “fist,” will be able to detect a different operator. Of course, if the enemy radio operators are good enough they can study tapes of the captured agent sending and imitate the agent’s fist, like a forger copying a signature. But then “all’s fair in love and war.” Q. Why do the secret agents we see in the movies always use Morse code instead of voice transmission on their radios?
A. It may be because most of the movies are
based on World War I- or II-era technology and CW was pervasive for some
very logical reasons. CW uses a much narrower signal than voice and is,
therefore, harder for intercept operators to find. CW, because of its
narrower signal can use the same power to go farther. You can use less
power and still get a long way with CW. Less power also makes it harder
for interceptors to pick up the signal. CW sets are less complicated to
build and can be made much smaller, making them easier to move around and
hide, as well as easier to build or repair in hostile territory.
To read the entire article, subscribe to SCANNING ScanTech Scanning “Vacationland”: Focus On Maine by Ken Reiss
Driving on the roads in and around our 23rd state you’ll see this nickname adorning the license plates. While it conjures images of carefree kicking back for some outdoor family fun—which you can certainly find in abundance—the state has its serious side, too. And it’s serious business protecting those roads. It was in 1921 that the State of Maine formed its first State Highway Police, with a mere 34-member force. A horsemanship test was actually required as a part of the process for appointment, although many officers were actually issued Harley Davidson Motorcycles instead. Today, the force is 341 officers strong and is the largest police force in the state. Maine’s interstate and highway system is their jurisdiction, but the force is also responsible for providing complete police protection in many areas of the state. There’s also a host of support services for smaller police departments, including detective, child abuse, major crime, underwater recovery, crisis negotiation, and tactical force. Two Cessna 182 (propeller) aircraft make up the air wing and are used for traffic enforcement, search and rescue, and transportation of officials throughout the New England area. In 2004, the Consolidated Communications bureau was established, not under the direct control of the state police, but as a separate entity under the state’s Public Safety Division. The bureau operates four regional communications centers at Augusta, Gray, Orono, and Houlton that provide most of the dispatch operations for the state police, fire, and emergency services, the warden service, drug enforcement agency, the Turnpike Authority, fire marshals, and marine and environmental protection services.
To read the entire article, subscribe to BROADCASTING Global Information Guide Where Have All The Signals Gone? Gone To 7200 (And Elsewhere) Every One, Plus More Changes Tracked by Gerry L. Dexter
We’re well into the A-09 broadcast season now and I’m sure you’ve all noticed that many broadcast signals between 7100 and 7199 have disappeared. That’s because communication regulatory agencies around the world have agreed that those 100 kHz should be assigned exclusively for amateur radio use. The first broadcasters you’ll hear on the 40/41 meter band will normally be at 7200. It’s going to be interesting to see whether some stations didn’t make the change right away. Certainly the majority did vacate the area, leaving the rest of the band busier as a result. There is still more action on the Zimbabwe radio front. A new broadcaster, Zimbabwe Community Radio, has begun transmissions on shortwave and, like the others, is in opposition to the Mugabe government. They are broadcasting into Zimbabwe from a site in the UAE (likely Dhabbaya) on 5995. The one hour broadcast is scheduled from 2000 to 2100—a shade too early in the day for anything but exceptional reception here. ZCR devotes its airtime to covering various economic, political, and social issues that the state-owned broadcaster ignores. I’m getting word that Radio Belarus has closed down, apparently due to budget problems. Nothing official has shown up on the Web yet; the official Radio Belarus site still lists 7210, 7255, and 7390 as in use and, indeed, reports of activity on those frequencies have since been noted. So let’s leave things up in the air for the moment, until we see how things shake out. Is Angola gone? Well, the country is still there but Radio Nacional on 4950 has been missing lately, and the 25 meter band outlet that used to be well heard at times has been missing for years—in fact, it isn’t even listed any longer. The only other option is 7217, which no one in the U.S. hears. So, if 4950 is really gone then the shortwave situation there barely retains a pulse.
Radio Teilfis Eireann was on shortwave again,
on a brief, test basis, with a transmission beamed from Meyerton, South
Africa. Word is that this test might result in RTE beginning a regular
service for Africa. However, RTE has not expressed much enthusiasm for
shortwave in decades. We’ll see.
To read the entire article, subscribe to BROADCASTING Broadcast Technology Enjoy The Old Ball Game The Old-Fashioned Way—On AM Radio by Bruce A. Conti
There’s nothing else quite like listening to
the boys of summer on the radio. Of all the professional sports, baseball
is the most perfect fit for radio, especially AM radio with night games
allowing for skywave reception of broadcasts from ballparks across the
country. As players take their positions on the field and the first batter
steps up to the plate, it’s easy to imagine being there when the umpire
shouts, “Play ball!” Listening to local announcers who are passionate about their home teams adds a level of intensity to the game that’s missing from national radio and TV network coverage. When watching nationally televised baseball games, real fans like to mute the television audio and turn on the radio to catch all the excitement as called by the home team experts. Many radio announcers are in fact well-credentialed former players for their respective home teams, while some are simply ardent longtime fans. For instance, Ron Santo, starting all-star third baseman for the ill-fated 1969 Cubs, now provides illustrious commentary for the WGN network coverage. Alan Ashby’s baseball career spanned 17 years playing for Cleveland, Houston, and Toronto before he retired to become the color commentator for the Blue Jays on “Team 590” CJCL broadcasts, which are carried by a transcontinental Canadian network of AM and FM stations. Professional sports broadcaster Joe Castiglione is now in his 27th year as the familiar radio voice of the Red Sox. Now here’s an interesting coincidence: Suzyn Waldman, ironically a former Bostonian perhaps following the footsteps of Babe Ruth, is now the color person for Yankees radio and the first woman to hold a full-time position as a Major League Baseball radio announcer. The Spanish-language radio announcers come with impressive credentials as well. Atlanta Braves radio analyst Fernando Palacios of “Viva 105.7” WWVA-FM once played for the Caguas Criollos and Arecibo Wolves of the Puerto Rico winter league. Enrique Oliu, the color man for Spanish broadcasts of Tampa Bay Rays baseball on “Genesis 680” WGES, also happens to be blind. (Amazingly Oliu isn’t the first blind baseball announcer. Blind announcer Don Wardlow provided color for the minor league New Britain Red Sox radio coverage in the 1990s, and ended his radio career with the Charleston River Dogs of South Carolina, proving that the combination of baseball and radio is indeed a grand slam.)
But don’t just listen for the home team
announcers, though. It actually can be a lot of fun to listen to an
opposing team’s commentators for a different perspective on the game. Check out our list of radio stations that broadcast Major League Baseball games. The flagship radio station for each team is listed first in italics, followed by key affiliates received over long distances at night. Select additional FM and low-power AM radio stations are included only to show the extent of some networks. While the Atlanta Braves network claims to be the largest in baseball, the New York Yankees Radio Network is widely prolific with affiliates as far away as Florida and Alaska. And, not to be outdone, some Boston Red Sox and Seattle Mariners games are carried on “Sports 1242” radio in Japan.
Complete network listings and announcer bios
are available online from the flagship radio station websites, baseball
team websites, or the mlb.com official site of Major League Baseball, but
also keep this list handy as a quick reference while scanning the radio
dial. If your favorite team is out of range on AM radio, the live
play-by-play of all games is also relayed nationwide on XM satellite
radio.
To read the entire article, subscribe to THE PRACTICAL SIDE The Antenna Room A Mariner’s Dozen—12 Antennas For Marine Frequencies by Kent Britain, WA5VJB
After you’ve had a chance to read this month’s cover feature and digest all the information Gordon West, WB6NOA, has provided in his extensive overview of the marine frequencies, your thoughts will naturally turn to how to better receive the signals you’ll find there. To help you out, we’ll show you how to build 12 (yes, 12) different designs for directional antennas for these frequencies. Be sure to check applicable FCC and maritime regulations, but these antennas will work just fine as transmitting antennas also. For this column, we’re going to divide the maritime VHF bands into three sections and offer up two different kinds of antennas designed for two different coax impedances for each of these three band segments. Photo A shows one of the two-element versions, and Photo B the higher gain three-element version. Be aware, though, that higher gain may not be the answer if you want to cover most of a harbor, or both directions along a coast. The two-element Yagi has 4 to 5 dB of gain and a broad pattern. The three-element Yagi has 6 to 7 dB of gain and narrower beam with a null off the back. We’ll also cover both 50 and 75 ohm versions. Most scanners are quite “happy” with 75 ohm antennas, and you also get to use RG-59 and RG-6 coax that’s often available from old satellite TV systems and cable TV drops. Most transmitters are designed for 50 ohm coax, but 75 ohm coax typically has less loss than 50 ohm, which is why the cable TV systems have standardized on 75 ohm coax. You’ll note that the elements are a bit farther apart with 75 ohm coax; that’s because I’m using the structure of the Yagi elements themselves to impedance match the driven element to the coax. With just small changes in its length, the same driven element is used on all 12 versions of these “Maritime Antennas.” The elements can be almost any metal rod material 1/8 inch to 1/4 inch in diameter, but for the driven element it’s nice to have something you can solder to. I often use bronze welding rod or solid copper wire (#10 to #12 works). For the bronze welding rod I’ll use a bit of copper or brass hobby tubing to splice two pieces together when the elements get this long.
Figure 1 shows lengths and spacings for our
design, and Figure 2 shows the basic design for the driven element used on
all 12 versions. Use the “B” dimensions for the length of the driven
element. The width of the loop on one side is about 1 to 1 1/2 inches
wide, though this is not a critical dimension. Refer to the tables below
for the element lengths and spacings.
To read the entire article, subscribe to THE INTERSECTION OF COMPUTERS AND RADIO RF Bits
One For The Monitoring
History Books, Plus Scanning by Dan Srebnick, K2DLS
When I’m in the shack, the scanner is frequently on. I live 25 miles south of the tip of lower Manhattan, so the attic-mounted discone antenna has no trouble pulling in signals from all around the metropolitan New York City region. My monitoring time is divided between the VHF/UHF amateur frequencies—both simplex and repeaters—and listening to public safety, marine, and aviation comms. I don’t want to miss anything important, so my scanner of choice includes P25 digital decoding. There are a few local municipalities that have made the switch to digital trunking. Any longtime scanner listener knows that, most of the time, the scanner traffic heard is relatively routine. Traffic stops, license checks, and ambulance and fire dispatch calls are frequently heard. Some days, however, the scanner comes alive and the inside scoop on a hot story is revealed. So it was on the afternoon of January 15, 2009, when Captain Chesley B. Sullenberger III, of US Airways Flight 1549, made an emergency landing in the Hudson River. This modern day American hero decisively glided his stricken plane into a perfect water landing not far from the site of the former World Trade Center and saved the lives of all 155 aboard. The radios came alive. NYPD Citywide 1 could be heard coordinating shore-based responders along the riverfront. I also found a lot of activity on 157.075 MHz, Marine Channel 22A. On this frequency, the responding US Coast Guard operation held court. The cutter Ridley, which seemed to be managing command and control on the scene, was in communication with NYPD aviation units, FDNY fireboats, and other craft on the scene (see Photo). Interoperability worked, and without the fancy digital upgrades and conversions that some would try to sell as necessary. All it takes is mutually agreed upon frequencies programmed into the radios, in advance. The Ridley is an 87-foot patrol boat assigned to Sector Long Island Sound. Its primary missions include Search and Rescue, law enforcement, and defense operations. It was in contact with Coast Guard resources responding from around the area which helped establish a 500-yard, later expanded to 750-yard, security perimeter to aid the salvage operation.
Kudos to Captain Sullenberger, the US Airways
flight crew, New York’s Finest and Bravest, the responding ferry boat
crews, the US Coast Guard, and to the passengers themselves. The American
spirit will continue to be inspired by this dramatic event, undoubtedly
making its way into the history books as an example of sorely needed good
news in this time of great difficulty for our nation.
To read the entire article, subscribe to PUBLIC SERVICE/SAFETY EmComm Essentials Mass Notification Systems: Distributing Vital Information by John Kasupski, KC2HMZ
This month we will take a look at a method of communicating that incorporates computers, personal communications devices, and more traditional means of mass communications such as public address systems to disseminate vital information during emergencies. It’s a method of communication that’s already in widespread use in government agencies, businesses, colleges and universities, and the military. If this technology is something you’ve never heard of, it’s my pleasure to introduce you so you can start spreading the word about mass notification systems (MNS). Many of you will recall what is now generally referred to as the Virginia Tech Massacre. This incident on April 16, 2007, consisted of two separate attacks approximately two hours apart on the Virginia Tech campus in Blacksburg, Virginia, during which a student who may have been suffering from a social anxiety disorder called selective mutism used a pair of handguns to kill 32 of his fellow students before committing suicide. An independent report issued in the aftermath of the incident questioned the timeliness and way Virginia Tech notified campus constituents after the initial dorm shootings. The report noted that “the protocol for sending an emergency message in use on April 16 was cumbersome, untimely and problematic when a decision was needed as soon as possible.” Virginia Tech’s internal reviews agreed that enhancements needed to be made to the emergency alert system on campus and implemented changes. Virginia Tech’s new MNS enables the school to contact faculty members and students via email, text messages, cell phones, and online instant messages sent to computers.
The incident at Virginia Tech and the
subsequent improvements made to the school’s MNS points out one
indisputable fact: When a disaster happens or is about to happen,
communications is the key to being able to alert everyone concerned in
time to avert death, injury, and loss of property. The problem in these
situations is that time usually does not allow for individual contact with
everyone concerned. Those in authority at schools, government/military
facilities, hospitals, and businesses must contend with issues common to
emergency management from a facility standpoint; that is, managing the
situation and saving lives, preserving data, properly shutting down
critical systems, etc. Very often in an emergency situation, so much time
is spent trying to communicate that it draws people away from these
primary responsibilities. Those so tasked seldom have time to contact
every nurse’s station, classroom, dormitory, or office in every building
they’re responsible for.
To read the entire article, subscribe to TWO-WAY RADIO Ham Discoveries Processors And Prophecy: Was Louis E. Frenzel, W5TOM, The Nostradamus Of Amateur Radio?
by Kirk Kleinschmidt, NTØZ Who among us hasn’t sat in front of the television at one time or another, eerily transfixed by the prophecies of ancient seers such as Nostradamus and Cayce? Ominous predictions, voiced by a narrator with a commanding baritone voice and backed by a soundtrack that could double for any suspense thriller, pinned us to the boob tube, nerves tingling, hair standing on end. During commercial breaks we began to breathe regularly and wondered how anyone so far back in time could predict “the future” with such startling accuracy. Such was my experience last week as I read Computers and Ham Radio, by Louis E. Frenzel, W5TOM (not the current holder of W5TOM), of Houston, Texas, in the March 1969 issue of Ham Radio magazine, which was subsequently acquired by Pop’Comm’s publisher. In his five-page article, Frenzel showed readers—in an era that featured Vietnam, Woodstock, and Neil Armstrong—an uncanny understanding of the role personal computers and computer technology would play in present-day ham shacks. The fact that he did this more than a decade before what we’ve come to know as the feeblest beginnings of the “personal computer revolution” is doubly amazing. These days, the convergence and symbiosis of radio and computers is almost a done deal. With the development of digital signal processing for the masses in the ’80s and ’90s (earlier DSP technology was developed for the military, etc.), computers were radios, and radios were computers. Don’t believe me? Remove the case from any PC and fire it up next to your radio’s antenna. You’ll hear just how much “radio” is involved in all computer hardware! Likewise, if you look under the hood of just about any commercially built amateur radio transceiver, you’ll see just how much circuitry is made possible by computers and microcontrollers. Again, we take all of this stuff for granted these days. In addition to using computers for logging, noise reduction, frequency synthesis, and modulating/demodulating more digital modes than you can count (and let’s not forget the Internet), radio has long since entered into a truly digital era, with software-defined radios poised to take ham radio as we know it into an exciting and even uncertain future. If you’d like to see what’s in store for all of us someday soon, check out the radios at Flex Radio Systems (<www.flex-radio.com>).
In fact, I plan to cover software-defined
radios in a future column, now that SDR technology is inexpensive,
especially in kit form, and can be enjoyed by everyone. But this month I’d
like to excerpt portions of W5TOM’s (NostraTOMus?) amazing article from
the past, and in doing so, I’ll provide some useful links to modern
software and hardware that essentially fulfills his ancient visions! Before we get specific, let me remind you that 1969-era computers were big, slow, and prohibitively expensive. The “desktop” computer Frenzel referenced in the article was a version of the Digital Equipment Corporation (DEC) PDP-8. It was about the size of a file cabinet drawer, had less computing power than today’s talking greeting cards, and cost about $10,000! And that’s without peripherals such as keyboards, paper tape readers, and teleprinters. Forget about CRT screens!
Compared to new cars and top-of-the-line ham
rigs, the PDP-8 was astronomically expensive. In an era when $2,000 could
buy the best Collins HF transceiver or a brand new car, the PDP-8 was just
under Ten Grand. In 2008 inflation-adjusted dollars, it would cost
$58,000! And there were no graphical user interfaces like Windows or OSX,
either. Heck, even DOS or UNIX would have been wild luxuries. The
PDP-8—with its whopping 4 kB of RAM—had to be programmed in “binary
machine code,” so you had to be a real computer weenie to use it (perhaps
you worked at Bell Labs?).
To read the entire article, subscribe to THE PRACTICAL SIDE The Wireless Connection Noise Alignment Techniques For Vintage Receivers by Peter J. Bertini
The past month life’s non-radio aspects have
been taking far too much of my time, so this column is going to be a bit
shorter than I’d like—my apologies. It will conclude next month with a
construction project for a very useful service instrument for your vintage
shop. But, for now, let’s discuss what needs to be done. Let’s consider a common alignment problem we’ve all encountered. Anyone who’s attempted to align the upper shortwave band on early consumer radios has probably noticed that’s very difficult to find the true peak—whether by watching the AGC level or audio level—when adjusting the RF trimmer. This is due to unwanted interaction between the RF tuning and the oscillator’s frequency. Here’s the drill we’ve all gone through: As the RF stage is peaked for maximum on a weak signal using the shop’s signal generator, the oscillator simultaneously is pulled off frequency. A simple alignment becomes a tedious merry-go-round of endlessly rocking the main tuning control back and forth to compensate for the oscillator pulling as we peak the RF stage tuning. In use, a stronger nearby signal can detune a weaker signal that was being listened to. Sigh. The weakness in these radios was in the converter stage, where a single tube served as both oscillator and mixer. While there isn’t much we can do to improve the inherent limitations that accompanies vintage technology, we can make our lives a bit easier on the test bench. There has to be a better way, and there is!
The amount of oscillator shift is usually
pretty small, and it usually isn’t enough to cause concern regarding dial
calibration. The dial markings for the upper shortwave ranges were often
at best done at 1 MHz or 500 kHz markings, thus a few kHz error wouldn’t
be resolvable on most dial scales. Besides, these sets often drifted many
kHz over several hours of usage due to temperature changes. But, if the
oscillator pulls (unwanted change in frequency due to an external
influence) several kHz, it will be enough to put the signal far enough
outside the IF stage band pass to severely attenuate the signal. Better
(more expensive) designs used separate tubes for the oscillator and mixer
to improve isolation and limit unwanted interaction. Vintage communications receivers often included an antenna trim control on the front panel. This control allowed the operator to peak the receiver front end for best sensitivity by compensating for minor alignment or tracking errors. Many operators learned that in the absence of a signal the trimmer could be peaked for maximum hiss on the speaker using atmospheric background noise picked up by the antenna. So, why not hook up an antenna and use this technique for peaking the RF tuning on the upper shortwave bands? After all, the atmospheric noise is broadband, and small shifts in the oscillator’s frequency would have no effect on the noise level within the IF band pass.
Ah, but here’s the rub! Very few of those
early converter tubes, even with an RF stage ahead of them, had noise
floors that were below the atmospheric floor. In other words, the
atmospheric noise is usually too weak to serve our needs.
To read the entire article, subscribe to THE PRACTICAL SIDE
Gordon West’s Radio Ways The
Rigs Of Summer— by Gordon West, WB6NOA
Handheld radios have varying degrees of “waterproof-ness.” Some must be kept dry, some survive spray, still others may go swimming with you. With warmer weather taking hobbyists and their equipment outside more, let’s look at the related specs you should understand.
If you provide communications with your local
fire department, a weatherproof rating for your HT will likely keep the
insides dry. Scout leaders may encounter some light rain out on the trail,
and a handheld rated as waterproof should do just fine. When you provide
communications for your local swift water rescue team, or work with the US
Coast Guard Auxiliary, the best choice is an HT that meets submersible
industry JIS and IEC ratings standards.
JIS stands for Japanese Industry Standard and
IEC stands for International European Com-munity specification, and
meeting their ratings requires passing a similar number of graduated water
intrusion test levels.
IEC specification 529 has many levels of water
protection. Here’s what they refer to: The IPX spray tests, up to IPX6, are considered “dynamic” tests, where water is either splashed or sprayed around the handheld under test. The intensity of the spray test might be IPX1 and IPX2, similar to falling rain; or, for IPX5, 6, and 7, a powerful spray jetted onto the product from specific angles. Meirion Buck of Adaptaflex Ltd. (<www.Adaptaflex.com>), a laboratory specializing in how IP ratings apply to equipment under test, explains: “For IPX6, the flow rate is 100 liters per minute for a duration of at least three minutes. This is a dynamic test that may vary quite considerably; an IPX4 rating is equivalent to water from a garden hose at typically 10 liters per minute for five minutes, through 180°, whereas an IPX6 is closer to a fire hose delivering 100 liters per minute for three minutes.” Most scanners and ham radio equipment are simply classified “weatherproof,” with no stated IPX rating. As you’ll soon read, there are several ham radio handhelds that specifically meet IPX7 static immersion tests. There are no ham radio handhelds rated for IPX8.
“Understanding IP ratings is extremely
important, especially IPX8, which should be qualified with a pressure
rating in barometric pressure,” says Buck. He illustrates his point using
an IPX8 rating at 15 bars for 30 minutes, which is an equivalent depth of
150 meters. No ham handheld could ever survive unless encased in one of
those handy clear flexible plastic enclosures.
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The Church
Rummage Sale UHF Television Station
by Shannon
Huniwell Anyone who can stand those insistent TV commercials for kooky adhesives, bra strap adjusters, effortless exercise equipment, and other valuable stuff inexorably glued to the catchphrase “shipping and handling,” might just enjoy at least one of the two video stories herein. (But that’s not all…If you read this entire article right now, I’ll throw in a few extra graphics and captions for free!) My father charged me nothing for a well-meaning TV pirate’s saga supposedly set in Virginia during the late 1970s. That’ll be the main transmitter in this column’s literary broadcast. I do admit being pretty skeptical about his story at first, but a related test-pattern image supplied by one of the viewers caused me to take the bait.
Before aiming my investigative scope at what
my dad remembered as the tale’s WGUN 45 TV, I’d initially like to flesh
out this month’s column with some television history that comes from a
more verifiable source than Sid Huniwell’s archives. Even dear old dad
admits the supporting “facts” in his informational arsenal can be roughly
the broadcast history equivalent of plot lines from that quirky X-Files TV
show. Proof of the above subtitle comes from the reputable Popular Science magazine. Its August 1949 issue offers the amazing expose of one Clarence Wolfe, Jr., also known by his video amateur callsign, W6JDI-TV. With years of ham radio experience (he was licensed while still in elementary school) but no formal electronics training, Wolf managed to beat KPIX-TV 5 (San Francisco’s first commercial telecaster) to the California airwaves by half a year. He accomplished this with a meager $500 worth of “secondhand tubes, war-surplus [radar] equipment” and lots of homebrew ingenuity. Wolfe’s cleverness jumped into high gear when he was deciphering how to mount an old 16mm movie lens, small tubes, and circuitry into some kind of affordable package suitable as a television camera. He decided on three 1-pound coffee cans soldered end-to-end with the lens mounted on the lid of the first can in the lineup. When the Popular Science author, Andrew Boone, visited W6JDI-TV, he noted Wolfe’s programming consisted of a static picture of a pretty brunette who viewers—mainly a handful of other San Francisco-area hams able to adapt their TV sets to snag signals in the 429 MHz area—dubbed Gwendolyn. When Wolfe sent her aloft on those ultra high frequencies, consumer UHF-TV that would begin with Channel 14 at 470 MHz (Channel 14) was still several years away. Boone described how the unusual ham station got its electromagnetic waves into the ether: “The [dipole] antenna array [consists of] short lengths of aluminum tubing 1-inch in diameter. Half carry power, the other half serve as reflectors.” This design allowed Wolfe to directionalize the output and generate a hefty gain away from the Pacific Ocean and towards the most populated communities near his Burlingame, California, city-of-license. Though his scratch-built audio/video transmitter could only manage 50 watts at the antenna jack, “in the favored direction,” Boone said, “field strength is equivalent to 5,000 watts.”
Wolfe’s debut telecast took place in May 1948
from “a weather-beaten back yard shack.” Wolfe started his transmitter
humming and Boone described the scene: “This is W6JDI-TV, broadcasting the
image of a girl on 429 mc, [Wolfe] said into a microphone suspended above
his battered desk. Do you see her?” For six months the skilled ham offered
the CQ without any response.
To read the entire article, subscribe to THE PRACTICAL SIDE The Propagation Corner How To Beat The Solar Minimum: Morse Code by Tomas Hood
In October 2008, I came across the website of the Straight Key Century Club (<www.skccgroup.com>). This club, also known as SKCC, is the fastest growing group of straight key Morse code operators in the world. First organized in January 2006, SKCC membership has grown rapidly to include thousands of members from all corners of the globe. The club promotes the use of manual keying devices (or, more simply, “keys’) when encoding letters, numbers, and punctuation in International Morse code. A manual key, also known as a straight key, is the human interface that allows the operator to make and break an electrical circuit in the dots and dashes. The International Morse Code is sometimes referred to as “CW” in amateur radio jargon because a continuous wave (CW) is turned on and off with the elements of the Morse code characters. The SKCC promotes the use of CW in the most original tradition of using only those keying devices that are controlled and powered by the human touch. Morse code uses a standardized sequence of short and long elements to represent the letters, numerals, punctuation, and special characters of a given message. The short and long elements can be formed by sounds, marks, or pulses, in on or off keying and are commonly known as “dots” and “dashes” or “dits” and “dahs.” The speed of Morse code is measured in words per minute (WPM) or characters per minute, while fixed-length data forms of telecommunication transmission are usually measured in baud or bps.
Why is it called “Morse code”? This character
encoding was devised by Samuel F. B. Morse, the creator of the electric
telegraph. This Morse code came in two flavors in the beginning. One was
in use by the railroads of America, and is known as American Morse Code,
and a unified, internationally used version (adopted by radio operators)
from that time is now known as the International Morse Code. Now, when
most people refer to Morse code or CW, they mean the international
version. Because my first love as an amateur radio operator is my manually controlled Navy Flameproof World War II Signal Key (see http://cw.hfradio.org/ for a photo of this key), I decided to join the SKCC, which is free. I was assigned my membership number and went to the website to explore more about the club. What I discovered was that I was really missing out on a lot of fun. The club offers a great number of great events, from short “sprints” (where you try to work as many other SKCC stations as possible during a given time period, often several hours) to weekend events that promote “ragchew” QSOs where you have conversations beyond the short exchange of the SKCC number and name, location, and signal report. There are plenty of incentives, too. What is unique and enjoyable about this is that the SKCC rules ensure that everyone is on a level-playing field. Only manual keys are allowed. No electronic or computer-driven CW. Only straight key operation is allowed.
Why would this be fun? I’ll give you an
analogy. A few years ago, I lived on the Olympic Peninsula in Washington
State. One of the nearest towns where I could shop for food and other
necessities was Port Townsend, located on the northeastern shore of the
Peninsula. This Victorian-styled port town features an active marina, and
on sunny, breezy weekend days was the center of boating.
To read the entire article, subscribe to THE LIGHTER SIDE The Loose Connection A Quadrabliffit Quandary by Bill Price, N3AVY
It’s way past time, but I’ve got some “prize-books” to put in the mail (and I’m very late at doing it). My “lighted-letter-board” design contest first drew a great entry by Jerry, K5JLW, a Texan who came up with a variation that sends large lighted dits and dahs upon pressing the appropriate key; and more recently, one from Robert Raynor from Long Island, who came up with a design so clever I should send him two books (and a pair of reading glasses). His design combined the idea of the well-known seven-segment LED, used in digital numeric displays—with the traditional light-bulb sockets that I had struggled with before I gave in and learned the code. I’m hoping that my feeble memory will have me putting books in the mail tomorrow morning from the Cowfield County Post Office. A tip of my rumpled hat to both of these first-class designers.
It’s been a quiet week at my HPJIE*. Quiet
because I’ve spent most of my time sitting and thinking. Wondering.
Wondering, that is, how to make these marvelous new digital displays (I
wish they were as simple as those designed by Robert Raynor), which might
someday tell me which direction my 30-foot satellite uplink dish is
pointing.
The first controller (which I believe used
Nixie tubes for displays—forerunners to seven-segment LEDs) failed
unceremoniously in the mid-’90s. A replacement was no longer available.
Its overpriced custom-designed-and-built replacement failed shortly after
its manufacturer skipped town, as did its next overpriced
custom-designed-and-built replacement. Both these costly replacements were
designed and installed using many obscure and esoteric wiring practices
and voodoo. The drawings and wiring diagrams that were supplied with both
replacements were made using special fading ink, hieroglyphics, cuneiform
writing (little wedge-shaped symbols pressed into Gruyere cheese).
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