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: 1 hour 2 min ago
If you have ever operated any sort of transmitting equipment, you’ve probably heard about matching an antenna to the transmitter and using the right co-ax cable. Having everything match — for example, at 50 or 75 ohms — allows the most power to get to the antenna and out into the airwaves. Even for receiving this is important, but you generally don’t hear about it as much for receivers. But here’s a question: if a 100-watt transmitter feeds a mismatched antenna and only delivers 50 watts, where did the other 50 watts go? [ElectronicsNotes] has a multi-part blog entry that explains what happens on a mismatched transmission line, including an in-depth look at voltage standing wave ratio or VSWR. We liked the very clean graphics showing how different load mismatches affect the transmission line. We also liked how he tackled return loss and reflection coefficient. There was a time when driving a ham radio transmitter into a bad load could damage the radio. But if the radio can survive it, the effect isn’t as bad as you might think. The post points out that feedline loss is often more significant. However, the problem with modern radios is that when they detect high VSWR, they will often reduce power drastically to prevent damage. That is often the cause of poor performance more so than the actual loss of power through the VSWR mechanism. On the other hand, it is better than burning up final transistors the way older radios did.
Three radio amateurs are among the initial nine NASA astronauts scheduled to fly on commercial spacecraft to the International Space Station. Others in the group are studying for their ham licensing exams in order to take part in Amateur Radio on the International Space Station (ARISS) school radio contacts, or because they have expressed interest in supporting ARISS events. The women and men chosen will be the first to fly the SpaceX Crew Dragon or Boeing CST-100 Starliner. SpaceX plans to fly a two-person crew — Robert Behnken, KE5GGX, and Doug Hurley — in Crew Dragon atop a Falcon 9 rocket from Kennedy Space Center. Boeing aims to launch a CST-100 Starliner capsule on an Atlas V vehicle from Cape Canaveral. It would carry a three-person crew — Eric Boe, Chris Ferguson, and Nicole Aunapa Mann, who attended an ARISS introductory talk at Johnson Space Center (JSC) and voiced interest in doing ARISS contacts in the future. At this point, however, her crew training will be stepped up to a more intense level.
United Nations Amateur Radio Club President James Sarte, K2QI, said on August 16 that their club station, 4U1UN, is several steps closer to getting back on the air after a long absence. “Dmitri Zhikharev, RA9USU, along with Adrian Ciuperca, KO8SCA, have been working with me behind the scenes to get the station operational again,” Sarte said. Generous donations from Zhikharev, Ed Kritsky, NT2X, and others, he said, enabled the station to obtain a rack-mounted K3, ACOM 2000 linear, and associated network-enabled control hardware. Another K3 to act as a remote head came from the estate of Tony Japha, N2UN, via his widow (4U1UN will operate from a remote operating position on UN grounds). “Finally, Adrian has been doing a lot of behind-the-scenes networking and legwork with his counterparts to help get things done from within the United Nations,” Sarte recounted.
Trying to work stations on 160 meters from Baker Island during the KH1/KH7Z DXpedition was fraught with challenges, and the WSJT-X FT8 digital protocol proved to be one answer to making contacts from the rare DXCC entity under tough, summertime conditions. DXpedition team member George Wallner, AA7JV, recently offered some observations about the experience that may be helpful to North American Top Banders. Wallner said the team was expecting easy conditions for Japan, which was closer, and difficult conditions for North America. “We got the opposite. The band would open to North America soon after our sunset — around 1800 local time — with very little noise. North American callers were initially weak but easy copy. Noise would start rising about 2 hours after sunset,” Wallner said in a July 12 post on the Topband reflector. “Fortunately, that was about the time the gray line was reaching the east coast, which brought up the signals well above the noise. Some east coast signals were quite loud.”
The FCC has issued a Citation and Order (Citation) to Amcrest Industries, LLC (formerly Foscam Digital Technologies, LLC), an importer and marketer of popular and inexpensive Baofeng hand-held transceivers, alleging that the company violated FCC rules and the Communications Act by illegally marketing unauthorized RF devices. The FCC asserts that Amcrest marketed Baofeng model UV-5R-series FM hand-held radios capable of transmitting on “restricted frequencies.” The Baofeng models UV-5R and UV-5R V2+ were granted an FCC equipment authorization in 2012 to operate under Part 90 Private Land Mobile Radio Service (Land Mobile) rules. “Under § 2.803 of the Commission’s rules, an entity may not market a device that is capable of operating outside the scope of its equipment authorization,” the FCC Citation said. “RF devices that have been authorized under Part 90 rules, such as the model as issue, must operate within the technical parameters established in those rules.” The FCC also maintained that the UV-5R 2+ is capable of operating at 1 W or 4 W, while the Part 90 Equipment Authorization limits the power output to 1.78 W.
Readers with not too many years under their belts may recall a time when the classic background sound effect for radio and television news programs included a staccato mechanical beat, presumably made by the bank of teletype machines somewhere in the studio, clattering out breaking stories onto rolls of yellow paper. It was certainly true that teletypes were an important part of the many communications networks that were strung together over the 20th century, but these noisy, greasy beasts had their day and are now largely museum pieces. Which is exactly where the ancient Model 19 Teletype machine that [CuriousMarc] and company are restoring is destined. Their ongoing video series, six parts long as of this writing, documents in painstaking detail how this unit worked and how they are bringing it back to its 1930s glory. Teletypes were made to work over telephone lines with very limited bandwidth, and the hacks that went into transmitting text messages with a simple 5-bit encoding scheme are fascinating. The series covers the physical restoration of the machine, obviously well-loved during its long service with the US Navy. Of particular interest is the massive power supply with its Thyratron tubes and their mysterious blue glow.
The currently silent packet radio system on the International Space Station could be back on the air by year’s end. Amateur Radio on the International Space Station (ARISS) hardware team members have located an original duplicate of the packet module that had been in use on the International Space Station (ISS) before failing more than a year ago after 17 years of service. With a new battery installed, the unit was tested and found to be functioning. The ARISS packet system in the space station’s Columbus module, operating on 145.825 MHz, quit last July after first experiencing some problems. All necessary paperwork has been completed to manifest the packet module on the Progress 71P spacecraft launch now set for Halloween, with docking on November 2. “Installation date will depend on the crew’s busy schedule, but ARISS hopes packet can be online again by the end of November 2018,” ARISS said this week in a news release. ARISS said it’s heard from “many hams” who have been asking when the packet system will be back on the air.
We love it when something common gets put to a new and unusual use, especially when it’s one of those, “Why didn’t I think of that?” situations. This digital clock with a suspended display is just such a thing. The common items in this case were “filaments” from LED light bulbs, those meant to mimic the look of clear-glass incandescent light bulbs. [Andypugh] had been looking at them with interest for a while, and realized they were perfect as the segments for a large digital clock. The frame of the clock was formed from bent brass U-channel and mounted to an oak base via turned stanchions. The seven-segment displays were laid out in the frame and the common anodes of the LED filaments were connected together, with the cathode for each connected to a very fine wire. Each wire was directed through a random hole in the frame and channeled down into the base, to be hooked to one of the four DS8880 VFD driver chips. The anode wires form a lacy filigree behind the segments, which catch the light and make then look a little like a spider’s web. It looks great, but nicht für der gefingerpoken – the frame is at 80 VDC to drive the LED segments. The clock is synced to the UK atomic clock with a 60-kHz radio link.
UK amateurs continue to make remarkable progress with innovative technology in the experimental 71MHz band. The BATC forum reports contacts of reduced bandwidth digital amateur TV of between 59 and 87km, using the latest high efficiency video coding. This follows the initial short range contacts when simplified NoV access to 70.5-71.5 MHz was introduced by Ofcom and the RSGB in June. See rsgb.org/nov for info.
You shouldn’t transmit encryption keys over Bluetooth, but that’s exactly what some popular wireless-enabled microcontrollers are already doing. This is the idea behind Screaming Channels, an exploit published by researchers at EUERCOM, and will be a talk at Black Hat next week. So far, the researchers have investigated side-channel attacks on Bluetooth-enabled microcontrollers, allowing them to extract tinyAES keys from up to 10 meters away in controlled environments. A PDF of the paper is available and all the relevant code is available on GitHub. The experimental setup for this exploit consisted of a BLE Nano, a breakout board for a Nordic nRF52832 Bluetooth microcontroller, a Hack RF, a USRB N210 software defined radio from Ettus, and a few high-gain antennas and LNAs. The example attack relies on installing firmware on the BLE Nano that runs through a few loops and encrypts something with tinyAES. Through very careful analysis of the RF spectrum, the AES keys can be extracted from the ether. Side channel attacks have received a bit more popularity over recent years. What was once limited to Three Letter Agency-level Van Eck phreaking can now be done inexpensively and in a system with devices like the ChipWhisperer.
The ARRL Board of Directors has adopted the recommendations of the Official Observer Program Study Committee, which would retire the Official Observer (OO) program and institute the Volunteer Monitoring (VM) program. The Board took the action at its July 20 – 21 meeting in Windsor, Connecticut, instructing that the transition “be implemented as soon as practicable.” Under the terms of the new program, current Official Observers will be invited to apply for appointment as Volunteer Monitors (VMs). The Board expressed its appreciation for the OOs and their dedicated volunteer service over the years. The Board said the action is expected to re-energize enforcement efforts in the Amateur Radio bands and was undertaken at the request of the FCC in the wake of several FCC regional office closures and a reduction in field staff. Coordination of cases and evidence gathering would become the responsibility of ARRL Headquarters staff, while the FCC will retain the responsibility for final decisions regarding action in specific cases.
This Bluetooth speaker is full of delightful surprises. The outer shell is an antique radio cabinet, but its practically empty interior is a combination of Dead Bug circuitry and modern BT receiver. [PJ Allen] found the BT receiver on Groupon and decided to whip up amplifier and threshold detector circuits using only parts he already had in order to make this vintage-looking Bluetooth speaker. The cabinet is from a Silvertone Model 1955 circa 1936. Don’t worry, no antiques were harmed in the making of this hack, the cabinet was empty when he bought it.
Citing poor health, AMSAT OSCAR Number Administrator — the individual who confers the alphanumeric designators on Amateur Radio satellites — has stepped down from the volunteer post after granting numbers to qualifying applicants for more than 2 decades. “I want to thank Bill for his many dedicated years of service to AMSAT,” said AMSAT President Joe Spier, K6WAO, who named AMSAT Vice President-Operations Drew Glasbrenner, KO4MA, to succeed Tynan. “Ever since the launch of OSCAR 1 in 1961, it has been traditional for Amateur Radio satellites to carry the name OSCAR — for ‘Orbiting Satellite Carrying Amateur Radio,’” Spier explained. OSCAR satellites are customarily referred to by hyphenated names, the first selected by the builder, AMSAT-OSCAR 7, abbreviated as AO-7. Spier called OSCAR numbers “a proud tradition of Amateur Radio, one that we hope to keep going for many years to come.”
Broadcasting has changed a lot in the last few decades. We have satellite radio, internet streaming, HD radio all crowding out the traditional AM and FM bands. FM became popular because the wider channels and the modulation scheme allowed for less static and better sound reproduction. If you’ve never tried to listen to an AM radio station at night near a thunderstorm, you can’t appreciate how important that is. But did you know there was another U.S. broadcast band before FM that tried to solve the AM radio problem? You don’t hear about it much, but Apex or skyscraper radio appeared between 1937 and 1941 and then vanished with the onslaught of FM radio. If you’ve heard of Apex radio — or if you are old enough to remember it — then you are probably done with this post. For everyone else, consider what radio looked like in 1936. The AM band had 96 channels between 550 and 1500 kHz. Because those frequencies propagate long distances at night, the FCC had a complex job of ensuring stations didn’t interfere with each other. Tricks like carefully choosing the location of stations, reducing power at night, or even shutting a station down after dark, were all used to control interference.
Johnson Space Center Amateur Radio Club Fires Up 1950s Vintage Gear for NASA on the Air Special Event
W5RRR, the Johnson Space Center Amateur Radio Club (JSCARC), is on the air as part of the NASA on the Air (NOTA) year-long special event — one of 12 NASA ham club stations participating in the event, which celebrates significant NASA milestones as the agency observes its 60th anniversary. This week, JSCARC members will focus operations on 80, 40, 20, 15, and 10 meters, as well as on satellites. A commemorative 1958 vintage vacuum tube vintage station will be activated. It pairs a Johnson Ranger transmitter and Courier amplifier with a Hammarlund HQ-145C receiver, courtesy of Kenneth Goodwin, K5RG, a JSARC member. “This station will be used to make CW, SSB, and AM QSOs,” Keith Brandt, WD9GET, said. “In addition, our other shack radios will use SSB, FT8, FM, CW, and SSTV to make contacts on all bands.” A special 60th anniversary QSL card — designed by AB5SS — will be available with an SASE for contacts made only to JSC Amateur Radio Club, 2101 NASA Rd. 1 M/C AW7, Houston, TX 77058. A certificate is available for top stations that work modes and bands across the NOTA NASA centers.
[Mr. Carlson] bought a Globe Scout Model 40A ham radio transmitter at a hamfest. The 40A was a grand old transmitter full of tubes, high voltage, and a giant transformer. It is really interesting to see how much things have changed over the years. The transmitter is huge but has comparatively few parts. You needed a crystal for the frequency you wanted to talk. There were two little modules that were precursors to hybrid circuits (which were precursors to ICs) that were often called PECs or couplates (not couplets) but other than those, it is all tubes and discrete components beautifully wired point-to-point. The really surprising part, though, is the back panel. There’s a screw terminal to drive the coil of an external coaxial relay that has line voltage on it. There’s also a plug on the back with exposed terminals that has plate voltage on it which is considerable. In the 1950s, you assumed people operating equipment like this would be careful not to touch exposed high voltage. [Mr Carlson] does a great job of walking through the schematic and, of course, also fires the radio up and looks at the output with a communication monitor. It has been a long time since we’ve loaded up a tube transmitter and watching it done while looking at the output was very nostalgic.
The FCC has issued a Notice of Apparent Liability (NAL) proposing to fine Jerry W. Materne, KC5CSG, of Lake Charles, Louisiana, $18,000 “for apparently causing intentional interference and for apparently failing to provide station identification on amateur radio frequencies,” the FCC said. “Mr. Materne was previously warned regarding this behavior in writing by the Enforcement Bureau and, given his history as a repeat offender, these apparent violations warrant a significant penalty,” the FCC said in the NAL, released on July 25. In 2017, the FCC received numerous complaints alleging that Materne was causing interference to the W5BII repeater, preventing other amateur licensees from using it. In March 2017, the repeater trustee banned Materne from using the repeater.
There are a multitude of radio shields for the Arduino and similar platforms, but they so often only support one protocol, manufacturer, or frequency band. [Jan Gromeš] was vexed by this in a project he saw, so decided to create a shield capable of supporting multiple different types. And because more is so often better, he also gave it space for not one, but two different radio modules. He calls the resulting Swiss Army Knife of Arduino radio shields the Kite, and he’s shared everything needed for one on a hackaday.io page and a GitHub repository. Supported so far are ESP8266 modules, HC-05 Bluetooth modules, RFM69 FSK/OOK modules, SX127x series LoRa modules including SX1272, SX1276 and SX1278, XBee modules (S2B), and he claims that more are in development. Since some of those operate in very similar frequency bands it would be interesting to note whether any adverse effects come from their use in close proximity. We suspect there won’t be because the protocols involved are designed to be resilient, but there is nothing like a real-world example to prove it. This project is unique, so we’re struggling to find previous Hackaday features of analogous ones. We have however looked at an overview of choosing the right wireless tech.
After the recent successful World Radiosport Team Championship in Germany it has been announced that the 2022 event will be hosted by Bologna in Italy. The invitation-only event pits the world’s greatest DXers against each other in over 60 teams. They compete with each other using similar stations in similar terrain to level the playing field. As far as possible, this means it comes down to a fair test of the operators’ sheer skill. The official website of the 2022 event is at wrtc2022.it.
Alaska’s super-power High-Frequency Active Auroral Research Program (HAARP) transmitters in Gakona, Alaska, will take advantage of the WSPR digital protocol and the Weak Signal Propagation Reporter Network (WSPRnet) during a short experimental campaign, July 30 through August 1. University of Alaska Fairbanks (UAF) Space Physics Group researcher and HAARP Chief Scientist Chris Fallen, KL3WX, told ARRL that he’ll be conducting research into ionospheric irregularities, but hardly with a weak signal. “I am conducting a dual-use experiment to create field-aligned — plasma density — irregularities while also modulating the HF beam for a WSPR beacon test,” he said. Specifically, Fallen will be looking at plasma density irregularities in the F-layer of the ionosphere.