This Week in Amateur Radio
This Week in Amateur Radio: North America's Amateur Radio News Magazine. Articles on amateur radio and news stories in the media featured here.
Updated: 55 min 42 sec ago
Amateur Radio operator and European Space Agency (ESA) astronaut Petro Duque, ex-KC5RGG/ED4ISS, has been named as the Minister of Science in the new Spanish government. Duque, 55, first went into space aboard the Shuttle Discovery in 1998, and in 2003 he spent a week on the International Space Station, carrying out Amateur Radio on the International Space Station (ARISS) contacts with two schools in Spain. Duque went to the ISS under a commercial agreement between the Russian space agency and the ESA. He also conducted a series of scientific studies during his ISS stay. Duque was Spain’s first astronaut.
The triode vacuum tube might be nearly obsolete today, but it was a technology critical to making radio practical over 100 years ago. [Kathy] has put together a video that tells the story and explains the physics of the device. The first radio receivers used a device called a Coherer as a detector, relying on two tiny filaments that would stick together when RF was applied, allowing current to pass through. It was a device that worked, but not reliably. It was in 1906 that Lee De Forest came up with a detector device for radios using a vacuum tube containing a plate and a heated filament. This device so strongly resembled the Fleming Valve which John Fleming had patented a year before, that Fleming sued De Forest for patent infringement. After a bunch of attempts to get around the patent, De Forest decided to add a third element to the tube: the grid. The grid is a piece of metal that sits between the filament and the plate. A signal applied to the grid will control the flow of electrons, allowing this device to operate as an amplifier. The modification created the triode, and got around Fleming’s patent.
ARISS-Russia is making FM transmissions on June 20 and 21 from two of its Tanusha series of CubeSats, now aboard the International Space Station. Russia’s ARISS organization has been developing the spacecraft in collaboration with Southwest State University in Kursk. Two earlier Tanusha CubeSats were hand-deployed by cosmonauts last August and are performing cluster flight experiments through communication links. Plans call for hand-deploying Tanusha 3 and 4 this August. On June 20, Tanusha 3 was to be connected to one of the ARISS antennas on the ISS Service Module to transmit greetings from students in several languages on 437.05 MHz. ARISS Russia is set to repeat the process on June 21 0730 – 1200 UTC on the same frequency. The ARISS-Russia team also plans to retransmit these signals on the standard ARISS 2-meter downlink, 145.80 MHz, using the JVC Kenwood TM-D700 radio now on the ISS. The next SSTV transmissions are planned for June 29 – July 1, with images commemorating the various satellites the ARISS-Russia team has developed and hand-deployed from the ISS. This will include SuitSat-1/Radioskaf-1, deployed in February 2006. — Thanks to ARISS-Russia
Sweden’s World Heritage Grimeton Radio Station SAQ Alexanderson alternator will be on the air on July 1 on 17.2 kHz for its annual Alexanderson Day transmission. Three transmissions are scheduled: Startup/tuning at 0815 UTC, message transmission at 0845 UTC; startup/tuning at 1015 UTC, message transmission at 1045 UTC, and startup/tuning at 1215 UTC, message transmission at 1245 UTC. All three transmission events will be available via YouTube. Amateur Radio Station SK6SAQ will be active on CW (7.035 MHz or 14.035 MHz) or SSB (3.755 MHz), with two operating positions planned. Send reports to SAQ and SK6SAQ via email or the bureau. The World Heritage Grimeton Radio station site will be open to the public on Alexanderson Day.
The Amateur Radio on the International Space Station (ARISS) “Ham Video” digital Amateur Radio TV (DATV) transmitter on the International Space Station (ISS) is reported to be defective, with onboard repair not possible. Also known as HamTV, the DATV system stopped working in mid-April, and a subsequent test on June 1 using a second L/S band patch antenna on the Columbus module had failed. ARISS-EU Mentor Gaston Bertels, ON4WF, said ARISS plans to return the transmitter to Earth to repair, pending space agency approvals and availability of ARISS funds. “Schools and crew members performing educational ARISS school contacts are delighted to use Ham Video,” Bertels said. “We will do the best we can to restart this service as soon as possible.” Following extensive testing, the Ham TV system was first used for an ARISS school contact in February 2016. — Thanks to ARISS
Radio Amateurs in Canada — primarily in the Province of Quebec — have mounted a petition drive demanding that members of the House of Commons prompt decisive regulatory action against a Quebec resident who has been causing deliberate interference. The petition does not spell out the particulars of the allegations but says the alleged offender — apparently unlicensed — is already known to authorities. Petitioners claim that the individual’s “malicious intentions” have been “threatening the security of emergency radio communication in the province,” and they called upon Parliamentary lawmakers “to ensure the security” of HF radio communication. “For 2 years, a Nicolet resident, near Trois-Rivières [Quebec], illegally set up a transmitting radio station and is generating interference on purpose,” the petition recounts. “Amateur Radio operators in Quebec have identified the illegal radio station and brought it to the attention of Innovation, Science and Economic Development (ISED) Canada, and its inspectors seized the individual’s radio equipment.” One of ISED’s functions is telecommunications regulation.
For hams who build their own radios, mastering the black art of radio frequency electronics is a necessary first step to getting on the air. But if voice transmissions are a goal, some level of mastery of the audio frequency side of the equation is needed as well. If your signal is clipped and distorted, the ham on the other side will have trouble hearing you, and if your receive audio is poor, good luck digging a weak signal out of the weeds. Hams often give short shrift to the audio in their homebrew transceivers, and [Vasily Ivanenko] wants to change that with this comprehensive guide to audio amplifiers for the ham. He knows whereof he speaks; one of his other hobbies is jazz guitar and amplifiers, and it really shows in the variety of amps he discusses and the theory behind them. He describes a number of amps that perform well and are easy to build. Most of them are based on discrete transistors — many, many transistors — but he does provide some op amp designs and even a design for the venerable LM386, which he generally decries as the easy way out unless it’s optimized. He also goes into a great deal of detail on building AF oscillators and good filters with low harmonics for testing amps. We especially like the tip about using the FFT function of an oscilloscope and a signal generator to estimate total harmonic distortion.
The International Amateur Radio Union (IARU) has welcomed the St. Kitts-Nevis-Anguilla Amateur Radio Society (SKNAARS) as its newest member-society. IARU member-societies on May 28 completed voting on the proposed admission of SKNAARS to the IARU to represent St. Kitts & Nevis. SKNAARS does not claim to represent Anguilla, which is already represented in the IARU by the Anguilla Amateur Radio Society; the inclusion of Anguilla in the SKNAARS name dates to an earlier time. With 56 affirmative votes required for admission, 62 affirmative votes were cast, with no dissenting votes. SKNAARS thus becomes a member of the IARU and of IARU Region 2.
As a beta test, the popular Reverse Beacon Network (RBN) has announced that it’s now offering a separate telnet feed for FT8 spots (telnet.reversebeacon.net port 7001), in addition to the current spot feed (telnet.reversebeacon.net port 7000), which will be repurposed to handle only CW and RTTY spots. In addition, a beta version of Aggregator Version 5 that can handle FT8 spots received from WSJT-X will be available on the RBN website, with instructions on how RBN node operators can configure their nodes to spot FT8 call signs on one or more bands; this will not interfere with the ability to spot CW and RTTY call signs, the RBN team assured in its announcement, explaining its reasoning for the move. The beta test follows a limited alpha test aimed at getting a feel for the spot load and other implications of carrying FT8 spots on the RBN. “The most striking characteristic of FT8 spots is their sheer quantity,” the RBN announcement said, citing weekday statistics from May 23 and 24 when FT8 spots represented 86% and 87% of all spots, respectively, while CW spots were 13% and 14%, respectively, and RTTY spots were below 1%. Throughput on both days totaled some 30,000 spots.
A mixer takes two signals and mixes them together. The resulting output is usually both frequencies, plus their sum and their difference. For example, if you feed a 5 MHz signal and a 20 MHz signal, you’d get outputs at 5 MHz, 15 MHz, 20 MHz, and 25 MHz. In a balanced mixer, the original frequencies cancel out, although not all mixers do that or, at least, don’t do it perfectly. [W1GV] has a video that explains the design of a mixer with a dual gate MOSFET, that you can see below. The dual gate MOSFET is nearly ideal for this application with two separate gates that have effectively infinite input impedance. [Stan] takes you through the basic circuit and explains the operation in whiteboard fashion.
Kosovo, which won its battle to become a DXCC entity earlier this year, appears to have another fight on its hands. International Telecommunication Union (ITU) Secretary-General Houlin Zhao has determined that the Z6 call sign prefix was never allocated to Kosovo. The Secretary-General issued his finding in the wake of a March 16 inquiry from Serbia, from which Kosovo declared independence 10 years ago, the last piece of the former Yugoslavia to do so. Serbia has continued to reject Kosovo’s secession. “ITU has not allocated call sign series Z6 to any of its member states,” Houlin Zhou said. “Consequently, the utilization of call signs series Z6 by any entity without a formal allocation and consent of the ITU represents an unauthorized and illegal usage of this international numbering resource.” Kosovo is not an ITU member state and is therefore not eligible to receive a call sign block allocation from the ITU. Houlin Zhou also informed the International Amateur Radio Union (IARU) that the ITU had not authorized use of the Z6 prefix, and he asked the IARU not to include Z6-prefix call signs on its website, where they have appeared since the 2015 admission of Shoqata e Radio Amatoreve te Kosoves (SHRAK) as an IARU member-society. An ITU sector member, the IARU complied with the request and advised SHRAK.
The phase locked loop, or PLL, is a real workhorse of circuit design. It is a classic feedback loop where the phase of an oscillator is locked to the phase of a reference signal using an error signal in the same basic way that perhaps a controller would hold a temperature or flow rate in a physical system. That is, a big error will induce a big change and little errors induce little changes until the output is just right. [The Offset Volt] has a few videos on PLLs that will help you understand their basic operation, how they can multiply frequencies (paradoxically, by dividing), and even demodulate FM radio signals. You can see the videos below. The clever part of a PLL can be found in how it looks at the phase of two signals. For signals to be totally in phase, they must be at the same frequency and also must ebb and peak at the same point. It should be clear that if the frequency isn’t the same the ebbs and peaks can’t line up for any length of time. By detecting how much the signals don’t line up, an error voltage can be generated. That error voltage is used to adjust the output oscillator so that it matches the reference oscillator.
A Washington, DC-based broadcast journalist and radio amateur, whose ability to speak was severely impaired a couple of years ago by a rare disorder, is adopting a technological solution to return his voice to the airwaves. ARRL member Jamie Dupree, NS3T, suffers from tongue protrusion dystonia, and he has limited speaking ability — he uses the barrel of a pen in his mouth to help better control his tongue. He had to drop off the broadcast airwaves and turn to print and online journalism to continue covering politics for Cox Media Group’s capitol bureau. But now, Dupree plans to leverage technology that will give him a fresh voice. Dupree, 54, a contester and Potomac Valley Radio Club member, said in a blog post this week that his plight attracted the attention of his colleagues at Cox Media Group, who mounted an effort at the company’s Atlanta headquarters to find a high-tech solution to get him back on the broadcast airwaves. “What they found was a Scottish company named CereProc, which agreed to sift through years of my archived audio and build a voice,” Dupree said. “The big news today is that it looks like that is going to work, and allow me to ‘talk’ on the radio again.” He’s calling it “Jamie Dupree 2.0.”
While 10 meters has not been the hottest band in the Amateur Radio toolkit of late, Iran apparently has found it an ideal spot to operate various radars. The interference was audible in International Amateur Radio Union Region 1 (IARU R1) and perhaps elsewhere in the world. “Iranian radars were very active on our 10-meter band every day [in May],” reported IARU Monitoring System (IARUMS) Coordinator for Region 1 Wolf Hadel, DK2OM, in the IARUMS newsletter. “On 28.860 MHz, we could daily receive the strong and long-lasting signals. Other frequencies were used in [frequency hopping] mode.” The list of additional Amateur Radio intruders on 10 meters included — or in some cases, no longer included — some of the usual suspects. Hadel reported that FM signals from Russian taxi dispatchers, driftnet fishery buoys, and Citizens Band “abusers” in Brazil have been operating on various 10-meter frequencies, “as usual.”
FEMA Region X (10), headquartered in Bothell, Washington, will exercise 5 MHz interoperability channels, as an option for disasters and emergencies, on the opening day of ARRL Field Day, Saturday, June 23, 1400 – 2000 UTC. Frequencies are 5.330.5, 5.346.5, and 5.403.5 MHz (USB). Stations from FEMA, the Department of Homeland Security, the US Army, Air Force, and Coast Guard, and the National Weather Service, and Amateur Radio stations will attempt to make contact on the three channels to test interoperability for a major disaster that significantly compromises the telecommunications infrastructure. FEMA Region X will use the call sign WGY-910. Although this exercise takes place during Field Day weekend, it's a FEMA exercise and not an official part of Field Day, which does not give credit for 60 meter contacts.
A 100 kW HF broadcast transmitter in Nauen, Germany, will send Field Day greetings to North American radio amateurs in MFSK64 mode during the weekly “Giant Jukebox” broadcast of The Mighty KBC on 9,925 kHz, June 24, 0000 – 0200 UTC. The MFSK64, centered on 1,500 Hz, will begin at about 0130 UTC. An RSID will be transmitted just before the transmission to guide decoding software to the correct mode and audio frequency. Reception reports are invited. — Thanks to Kim Elliott, KD9XB
The Colpitts oscillator is a time-tested design — from 1918. [The Offset Volt] has a few videos covering the design of these circuits including an op-amp and a transistor version. You can find the videos below. You can tell a Colpitts oscillator by the two capacitors in the feedback circuit. The capacitors form an effective capacitance for the circuit (assuming you have C1 and C2) of the product of C1 and C2 divided by the sum of the two capacitors. The effective capacitance and the inductance form a bandpass filter that is very sharp at the frequency of interest, allowing the amplifier to build up oscillations at that frequency. It is unusual to show an op-amp oscillator, and it is interesting to think about the design changes and limitations discussed in the video. The video isn’t just theoretical. He also builds the circuit and looks at the real world performance.
Experimental operations now under way on HF appear aimed at leveraging low-latency HF propagation to shave microseconds from futures market trades and gain a competitive edge in a field where millionths of a second can mean winning or losing. Bloomberg on June 18 reported on a secretive antenna facility near Maple Park, in Kane County, Illinois, and speculated that futures traders might be looking to take advantage of lower-latency HF propagation over state-of-the-art microwave links and undersea cables, where even the slightest path delay could compromise a transaction. The facility is not far from a major futures data center. As the Bloomberg article explained, “Rapidly sending data from there to other important market centers can help the speediest traders profit from price differences for related assets. Those money-making opportunities often last only tiny fractions of a second.”
W1AW has announced its Field Day bulletin schedule. Those participating in Field Day can earn 100 bonus points for copying the special Field Day bulletin transmitted by W1AW or by K6KPH during its operating schedule on Field Day weekend. The Field Day bulletin must be copied via Amateur Radio. An accurate copy of the message must be included in your Field Day submission in order to earn the bonus points, which are available to all operating classes.
Two major DXpeditions are on track to make many DXers happy campers this year. Just ahead is the KH1/KH7Z Baker Island DXpedition, which commemorates the 81st anniversary of aviator Amelia Earhart’s disappearance on July 2, 1937, near Baker and Howland islands, as well as “the commitment and sacrifices” of the Hui Panalā’au (loosely translates to “society of colonists”) — young high school graduates from Hawaii who were taken to colonize Baker, Howland, and Jarvis islands from 1935 until 1942, and who began construction of a runway for Earhart to land in 1937. The islands were bombed the day after Pearl Harbor, killing two, and the colonists were removed by the US Coast Guard in 1942. The team’s enthusiasm level was reported to be high, as the KH1/KH7Z Baker Island team prepared to depart Pago Pago, American Samoa, on June 20 aboard the Nai’a, en route to Baker Island. The DXpedition is scheduled to fire up around 0000 UTC on June 28, with eight operating positions active on all open bands. The team will be on the air around the clock — and on 20 meters continuously — for the following 10 days. The KH1/KH7Z team consists of 14 operators.