Category Archives: AM

Matt’s 2022 Portable Loop Antenna Shootout

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Many thanks to SWLing Post contributor, Matt Blaze, for the following guest post:

Matt’s 2022 Portable Loop Antenna Shootout

by Matt Blaze, WB2SRI

Followers of this blog may be familiar with my “shortwave radio shootouts” that I post from time to time. The idea is to compare how well different radios demodulate the exact same signal. Basically, I take a bunch of radios, hook them up to the same antenna via an RF distribution amplifier, tune the radios to some distant signal, and record the audio output from them simultaneously. Sometimes that kind of comparison can be more revealing of actual real-world performance than lab measurements or technical specifications.

The other day, I decided to do the same thing, but for antennas instead of radios. Essentially, I inverted the setup. Instead of hooking up different radios to the same antenna, I hooked up identical radios to different portable antennas and recorded them demodulating the same signals at the same time.

In this first of perhaps a series of these antenna shootouts, I wanted to compare three portable amplified magnetic loop antennas. When I say “portable” here, I mean broadband antennas that can pack reasonable compactly for travel and that can be set up and broken down easily for use “on location”, say on a picnic table or hotel balcony, or perhaps installed temporarily on a roof, without too much fuss.

The antennas are:

– The Wellbrook FLX1530LN with a 1 meter diameter loop of LMR400 coax. This is my “standard” portable antenna (I use a telescoping broom handle for the support; I wrote about it here as the “signal sweeper” last year). Excellent performance, but on the bulky side for travel. Performs well from LW through HF. Not cheap, at about USD 225 including shipping for the amplifier and power injector, but not including the loop, mounting hardware, or feedline.

– The Wellbrook FLX1530LN with a 0.5 meter diameter loop of RG142 (a stiff “aircraft grade” version of RG58 that holds it shape well at this size). I used some 1/2 inch PVC pipe as the vertical support. Because of the smaller diameter loop and thinner coax, it packs down to a much smaller and lighter package than the 1 meter LMR400 version.

– The K-180WLA, an inexpensive (about USD 60) 0.5 meter loop from China, sold on eBay and Amazon. The loop is steel wire (which can be wound down to a small diameter for transport), and the kit includes everything you need, including a rechargeable power injector. (However, the power injector uses a noisy voltage booster, so I substituted my own bias-T injector for these experiments). Ostensibly covers LW through VHF, but the low end coverage is, shall we say, somewhat aspirational, as you will see.

– I also recorded, for comparison, the built-in ferrite bar (for LW/MW) and whip antenna (for HF) of the receiver.

This is, of course, only a small sampling of portable loop antennas, both commercial and homebrew. But I wanted to start with what I had on hand and with what meets my own needs. (I omitted from consideration loops that require tuning, since I want to be able to install the antenna without needing access to it every time I change frequency).

For each signal captured, I oriented and positioned each antennas to maximize signal quality, taking care to move them away from each other and interfering metal objects. So you’re hearing (approximately) the best each antenna had to offer (on my roof under suboptimal band conditions).

The receivers I used were four Sangean ATS-909×2 portable LW/MW/SW/FM/Air radios. I believe this to be the best currently available (relatively inexpensive) portable shortwave receiver on the market. It has excellent performance (and is admirably resistant to overload and intermod when used with an active antenna). It lacks a sync mode, but that’s rarely implemented well on portable radios anyway. As a practical matter, it has a good line-level output jack, and I already happened to own four of them.

As in my other shootouts, for each signal, there are a total of five recordings: a monoaural recording of the audio from each of the four antennas, plus a narrated stereo recording comparing a reference (the 1M Wellbrook) on the Left channel with each of the other antennas in succession on the Right channel. The stereo recording is intended as a quick overview, but it will only make sense if you listen in stereo, preferably with good headphones. (You can switch the earcups to get a quick comparison as you listen.)

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Radio Waves: AM/FM Receiver Sales Stabilize, Asheville Radio Museum Adds Model HS2, Legacy remains of WSY, and Farewell to WCFW

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Radio Waves:  Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

AM/FM Receiver Sales Have ‘Stabilized’ Even As Audio Turns Up On More Devices. (Inside Radio)

Anyone who has tried to find an AM/FM receiver in a big box retailer knows they are not as easy to find as they once were. It is little surprise then that the Consumer Technology Association expects fewer to sell this year. But at roughly five million units now sold each year, CTA expects that number to hold steady in the years to come, in part due to the role radio plays during emergencies.

“That category has stabilized,” said Rick Kowalski, Director of Industry Analysis and Business Intelligence at CTA. “It’s a low number relative to other categories, but there’s a steady demand, just in terms of people having an AM/FM radio for those situations where you might need a battery-powered radio as a backup.”

CTA forecasts 4.7 million traditional radio receivers will be sold this year in the U.S. That is six percent lower than the five million units sold in 2021. “Looking out in the next five years. It’s not going to get much lower than that,” Kowalski said in an interview.

CTA projects 24.5 million smart speakers will sell this year, or roughly five-times as many as traditional radio receivers. But in what may be a surprise to many, that estimate is actually two percent lower than the 25 million smart speakers that CTA says were sold last year. [Continue reading…]

“Bringing it home” Asheville Radio Museum adds local piece of history to its collection (WLOS)

ASHEVILLE, N.C. (WLOS) — The Asheville Radio Museum has added a new piece of history to its’ collection!

It’s a 1922 radio receiver built by an Asheville-based business.

The model HS2 radio the museum procured is only one of two known to exist.

Collector and restorer Robert Lozier found that it was the first name brand radio built in North Carolina.

News 13 spoke to the director of media communications Peter Abzug about why this radio is so significant.

“Having this radio here, in Asheville, where it was built is really significant,” he said. “It’s bringing it home. Although the company itself didn’t last for years and years, it did employ people and it was a significant part of Asheville’s history, and something we can be very proud of.”

Click here to watch the video at WLOS.

Legacy remains of WSY, Alabama’s first radio station (Alabama News Center)

Innovation is at the historic heart of Alabama Power, beginning with its founding in 1906 and Capt. William Patrick Lay’s vision of electrifying the state by harnessing the power of Alabama’s rivers.

But the company’s embrace of another cutting-edge technology, just 16 years after Alabama Power’s incorporation, is also historic.

One hundred years ago this year, on April 24, 1922, Alabama Power hit the airwaves with the state’s first operating radio station. WSY (an acronym for “We Serve You”) began broadcasting from rented space in a building on Powell Avenue in Birmingham.

The 500-watt AM station was initially designed as a company tool, to provide better communications among employees – especially those in the field and at remote generating plants. In fact, radio technology was so new – regularly scheduled radio programming in the United States started only in 1920 – Alabama Power engineers had to design and build most of WSY’s transmitting equipment.

“We began assembling the set … with intentions of using it for purposes of operation of the system exclusively,” wrote George Miller, the employee in charge of the station, in the July 1922 issue of the company’s Powergrams. “The broadcast feature came up, though, and materially changed our plans.”

Indeed, a month before the station went on the air, The Birmingham News published a do-it-yourself piece about “how to make your own radiophone receiving set” so local residents could pick up WSY when it began broadcasting.

Interest in the station was so strong that within weeks it began offering entertainment programs, according to “Developed for the Service of Alabama,” the centennial history of Alabama Power, written by noted historian Leah Rawls Atkins.

Dee Haynes, with the Alabama Historical Radio Society, recalled one story that underscores WSY’s popular embrace. Soon after WSY went on the air, earpieces began disappearing from the handsets of payphones all over Birmingham, apparently because people were swiping them to use in home-built receiving sets. [Continue reading…]

FAREWELL TO FM: A Grandson’s Recollections of His Family’s Legacy Radio Station, WCFW (Volume One)

For 54 years, WCFW has been a beloved independently owned radio station on 105.7FM. But for lifelong Eau Claire resident Parker Reed, it has been more than that: it’s his family’s life, love, and legacy.

A catchy jingle – featuring the melody “WCFW, where FM means fine music” – came across a young radio station owner’s desk in 1969.

It was short, simple, and it worked. The owner paid $25 for it, and more than 50 years later that same jingle – which has aired thousands of times on 105.7FM radio – exemplifies the values of WCFW in Chippewa Falls and the couple who have owned it for over half a century: simplicity and consistency.

My grandparents, Roland and Patricia Bushland, have owned and operated WCFW since its inaugural broadcast on the airwaves on Oct. 20, 1968. Earlier this summer, they decided to end their 54-year stint in radio, selling the legacy station to Magnum Media – a Wisconsin-based media organization owned by Dave Magnum who now owns 25 radio stations across the state and will take over operations of the quaint, easy-listening station later this fall.

It’s a bittersweet moment – for the community, yes, but especially for our family, for whom the station has been an integral part of our lives for decades.

“It’s hard to not have mixed feelings about it, because it was our life for so long,” said my grandmother, Patricia Bushland. “When you start something, and you’re the only people who ran it all those years, you get attached to it. But after so many years, I’m thrilled to death that someone new is coming in, and we can finally take a break.”

When my grandfather, Roland, was young, he would draw pictures of radio towers during school – as his life too began with radio, front and center. My great-grandfather Roy Bushland owned and operated multiple Bushland Radio Specialties storefronts in Chippewa Falls and Eau Claire since the early 1930s – a business where my grandfather got his start in 1952 after he graduated Chippewa Falls High School as salutatorian. [Continue reading…]

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The AMT-MW207 mini AM radio transmitter kit

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Many thanks to SWLing Post contributor, Frans Goddijn, who shares the following video demonstrating the AMT-MW207: a tiny $25 mediumwave transmitter kit that can be purchased on AliExpress:

To be clear, the AMT-MW207 is not designed to be a whole house AM transmitter like the SSTran and others.

The seller describes it as a device to debug and test AM receivers. Since it only employs a built-in bar antenna, the transmitter would need to be placed in close proximity to the receiver.

Click here to view on AliExpress.

Thanks for the tip, Frans!

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Wlodek Shares an Air Raid-Prompted Radio Comparison

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Many thanks to SWLing Post contributor and friend, Wlodek (US7IGN), who writes from Kiev:

Hello!

Because of another air raid alert, I can’t sleep and I decided to make a small comparison of the receivers of the 60s and the modern one.

Of course, you can not compare their size and weight, as well as some features.

This Chinese XHDATA D-808 was given to me by a friend for comparison. When he was just choosing a good receiver, I advised him to buy an old Sony 7600 series or Panasonic B65, for example. But he decided that modern technology is better at handling the task of receiving. But it turned out to be not so clear:

Click here to view on YouTube.

Radios:

73 de US7IGN!

Thank you for sharing this, Wlod. I wish the circumstances for the radio comparison were better–even though I know air raids have sadly become a fact of life for many in Ukraine, I can’t imagine sleeping through them. 

Your short comparison is interesting too. I consider the D-808 to be an excellent little DSP portable, but the audio simply can’t compare with your vintage radios. Indeed, the vintage receivers seem to handle the QRM a bit better than the D-808 as well.

Thank you for sharing this and wishing you the very best, OM.

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Radio Waves: DRM Demo in Australia, Decoding the JWST, the ARDC, and EV Makers Dropping AM Radio

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Radio Waves:  Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Australia Demonstrates DRM on AM, FM (Radio World)

Since September 2020, ABC Radio has been quietly trialing DRM technology in Victoria

The public-service Australian Broadcasting Corp. and its transmission contractor BAI Communications Transmission Network hosted a public demonstration of Digital Radio Mondiale broadcasts on June 29, 2022. ABC highlighted the use of DRM on both AM and FM in Wagaratta, Victoria.

According to the DRM Consortium, the demonstration was the culmination of almost two years of COVID-impacted work to assess the performance of DRM services in Australia’s VHF and medium-wave bands.

Previously, the Australian Amateur Radio Experimenters Group reported that AREG member Steve Adler (VK5SFA) had been monitoring “a very un-publicized Digital Radio Mondiale (DRM) trial” on 747 kHz from Wangaratta in August 2021.

The Australian Communications and Media Authority provided ABC with a license variation to conduct the DRM 30 trials from September 1, 2020, to August 31, 2022.

At the public demonstration, senior representatives from the public, commercial and community radio sectors, along with regulators and other interested parties, were able to hear and see the capabilities of DRM broadcasting on AM from Dockers Plains and on FM from Mount Baranduda. They were also able to review the transmission equipment at Wagaratta.[Continue reading…]

Also check out the DRM Consortium’s article on this same topic.

Decoding James Webb Space Telescope (Daniel Estévez)

The James Webb Space Telescope probably needs no introduction, since it is perhaps the most important and well-known mission of the last years. It was launched on Christmas day from Kourou, French Guiana, into a direct transfer orbit to the Sun-Earth L2 Lagrange point. JWST uses S-band at 2270.5 MHz to transmit telemetry. The science data will be transmitted in K-band at 25.9 GHz, with a rate of up to 28 Mbps.

After launch, the first groundstation to pick the S-band signal from JWST was the 10 m antenna from the Italian Space Agency in Malindi, Kenya. This groundstation commanded the telemetry rate to increase from 1 kbps to 4 kbps. After this, the spacecraft’s footprint continued moving to the east, and it was tracked for a few hours by the DSN in Canberra. One of the things that Canberra did was to increase the telemetry rate to 40 kbps, which apparently is the maximum to be used in the mission.

As JWST moved away from Earth, its footprint started moving west. After Canberra, the spacecraft was tracked by Madrid. Edgar Kaiser DF2MZ, Iban Cardona EB3FRN and other amateur observers in Europe received the S-band telemetry signal. When Iban started receiving the signal, it was again using 4 kbps, but some time after, Madrid switched it to 40 kbps.

At 00:50 UTC on December 26, the spacecraft made its first correction burn, which lasted an impressive 65 minutes. Edgar caught this manoeuvre in the Doppler track.

Later on, between 7:30 and 11:30 UTC, I have been receiving the signal with one of the 6.1 metre dishes at Allen Telescope Array. The telemetry rate was 40 kbps and the spacecraft was presumably in lock with Goldstone, though it didn’t appear in DSN now. I will publish the recording in Zenodo as usual, but since the files are rather large I will probably reduce the sample rate, so publishing the files will take some time.

In the rest of this post I give a description of the telemetry of JWST and do a first look at the telemetry data. [Continue reading…]

Helping Secure Amateur Radio’s Digital Future (Hackaday)

The average person’s perception of a ham radio operator, assuming they even know what that means, is more than likely some graybeard huddled over the knobs of a war-surplus transmitter in the wee small hours of the morning. It’s a mental image that, admittedly, isn’t entirely off the mark in some cases. But it’s also a gross over-simplification, and a generalization that isn’t doing the hobby any favors when it comes to bringing in new blood.

In reality, a modern ham’s toolkit includes a wide array of technologies that are about as far away from your grandfather’s kit-built rig as could be — and there’s exciting new protocols and tools on the horizon. To ensure a bright future for amateur radio, these technologies need to be nurtured the word needs to be spread about what they can do. Along the way, we’ll also need to push back against stereotypes that can hinder younger operators from signing on.

On the forefront of these efforts is Amateur Radio Digital Communications (ARDC), a private foundation dedicated to supporting amateur radio and digital communication by providing grants to scholarships, educational programs, and promising open source technical projects. For this week’s Hack Chat, ARDC Executive Director Rosy Schechter (KJ7RYV) and Staff Lead John Hays (K7VE) dropped by to talk about the future of radio and digital communications. [Continue reading…]

Interference causes EV makers to drop AM radio (Radio World via the Southgate ARC)

Radio World reports the Electromagnetic Interference generated by Electric Vehicles is causing some EV automakers to drop AM (medium wave) radio

The article says:

Some EV automakers are dropping AM altogether due to audio quality concerns, but that’s just one piece of the puzzle as radio continues to fight for space on the dash.

“As carmakers increase electric vehicle offerings throughout their lineups, the availability of AM radio to consumers is declining,” said Pooja Nair, communications systems engineer with Xperi Corp., in a Radio World guest commentary. “This is because the effects of electromagnetic interference are more pronounced in EVs than in vehicles with internal-combustion engines.”

In other words, electromagnetic frequencies generated by EV motors occupy the same wavelength as AM radio signals. The competing signals clash, effectively cancelling each other out. As EV motors grow more powerful, AM static tends to increase.

Read the full story at
https://www.radioworld.com/news-and-business/headlines/why-are-some-automakers-ditching-am-radio

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Can the Eton Elite Satellit meet 2022 expectations?

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Many thanks to SWLing Post contributor, Dan Robinson, for the following guest commentary:

The Elite Satellit: Can Eton Deliver to Radio Users Who Expect Higher QC and Feature Standards?

by Dan Robinson

It’s been many years since the original E1 took the hobby world by storm. Everyone remembers the issues that plagued the E1, from the rubber coating that degraded over time, to display and encoder issues, and the calibration issues that frustrate some users.

In anticipation of the arrival of the Elite Satellit, I got both of my E1s out of storage — one in the 9xxx serial number range required a de-gooing session, accomplished quite well using Max Pro cleaner and 70% alcohol. It was interesting note, during that process, that the XM module on one side of the radio was more sensitive to color loss than other parts of the cabinet, reducing to an almost silver color when all was finished.

Original Eton E1 XM

Using the original E1s provided a reminder of how good these receivers were and still are, if you have managed to avoid display and encoder issues. The combination of PBT, triple selectivity and highly-effective SYNC was a blockbuster combination. The radio failed only in the area of quality control.

As Universal Radio and other distributors prepare to send out the first tranche of receivers, some thoughts are in order. The first is that one hopes Eton has lessons from the first go around regarding Quality Control. I have a sinking feeling about this based on my experiences in recent years reviewing receivers by Tecsun.

Eton needs to know that those who will buy the Elite Satellit, and that includes old-timers like myself but newcomers to the hobby, now have much higher standards specifically because of the features we have seen Tecsun and some other manufacturers put in portables.

Primarily, the presence of a recalibration capability really poses a challenge where the Elite Satellit is concerned. Discerning buyers no longer have to put up with a radio that has calibration and/or stability problems. This is why I am curious as to whether Eton included an adjustment function through software or an adjustment hole as with the original E1. So far, there has been no confirmation on this question from Eton or anyone else.

Original Eton E1 XM

With an older E1, tweaking of the master oscillator was possible through the small adjustment hold in the rear of the radio cabinet. This was tricky since in many units the hole was inconveniently located directly under one of the plastic ribs on the back.

I solved this problem by gently cutting a small section of one rib with a Dremel or similar tool, providing easier access. Still, adjustment has to be done carefully due to the sensitivity of the pot, and preferably with a non-metallic jewelers flat head screw driver. Even then, movements of the radio would often throw the radio back off.

But again, E1 users were spoiled by the recalibration capability which Tecsun included on receivers from the PL-880 to the 990x and 501s and even the PL-368, all of which provide a software method of zeroing frequency in SSB. Even Malahit SDRs have a fine adjustment setting in software.

If Eton has not taken this into account, and has not made any recalibration possible, I fear that it may face a good number of buyers who will simply return radios that suffer from significant frequency error. In short, a “good enough for government” approach by Eton when it comes to calibration QC is simply not going to be sufficient because for years now, Tecsun has been setting a higher standard.

Physical cosmetic issues too will also be an important indicator as to Eton’s attention to QC. If Eton learned its lesson from the rubberized cabinet fiasco, this should not be a major problem. But I would urge owners of the new Elite Satellit to examine your radio for QC issues, like LCD pixel problems, wobbly knobs and loose encoders, and issues with the telescopic antenna.

All of this becomes even more important because Eton is charging so much for this radio. Even taking inflation into account since the original E1 appeared, $599 for a radio that adds only HD and AIR band as features, but which still might suffer from QC problems is extremely high and I fear Eton may end up with numerous returns if the Elite Satellit fails in any key areas.

So, the clock ticks down to the moment when many of us will receive that box containing the Eton Elite Satellit. The question is will what is inside be able to meet the higher standards we have come to expect from a multi-band portable?

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Giuseppe’s latest homemade ferrite antenna for MW and SW

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Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who writes:

Dear friends,

I’m Giuseppe Morlè from Formia, central Italy on the Tyrrhenian Sea.

I want to share with you my latest ferrite antenna for listening; it is composed of 3 ferrites of 20 cm each in a tube for electrical systems with 2 separate windings, one for medium waves and one for short waves, 40 turns for medium waves, 4 turns for short waves. I use a 750 pf variable to tune the 2 windings and a switch is used to eliminate a winding.  Since there is only one variable, if you listen to the medium waves I interrupt the winding of the shorts.

On shortwaves it is preferable to place the system on an iron railing which, due to inductive effect, behaves like a really long wire antenna.

For the mediumwaves it is enough to bring the receiver close to the ferrites and also in this case, the induction will have its effect with an excellent increase in signal and modulation.

The range of this portable antenna is:

      • 520 to 1800 kHz
      • 3.500 to 18.000 MHz

Here’s a video from my Youtube channel where I explain how it works:

I had previously built a similar antenna but with 12 cm ferrites–very portable.

Thank you for your attention and I wish you good listening.

73. Giuseppe Morlè iz0gzw.

This is brilliant, Giuseppe! I love how you never stop building and experimenting with various antenna designs! Thank you for sharing this with us!

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