Author Archives: Thomas

Guest Post: Tom takes the AirSpy HF+ and YouLoop to the field!

Many thanks to SWLing Post contributor, Tom Lebryk, who shares the following guest post:

YouLoop Picnic Table Report

by Tom Lebryk

So, I finally got around to testing my Airspy YouLoop after the long shipping delay from China. It is simple in concept and will not repeat what others have written about it in previous articles. I find it a useful loop antenna for portable operations and sometimes for noisy home use. This report is focused on my usual field location from a Northern Illinois county park picnic table.

Setup

As you can see from the setup photo, it all fits into a backpack except for the two PVC pipes and crossbar which are easy carried. I modified my YouLoop to use the 2 meter transmission line as one half of the loop. The other half consists of the two shorter wires connected with a simple female-to-female SMA connector. This doubles the circumference of the loop and gives it a bigger capture area.

Crossbar

Because my setup is bigger than usual, I had to find a lightweight cross member to aid the solid conductor wire from sagging. I found just the thing in a larger-than-normal 6 foot fiberglass driveway snow marking stick sold at the local hardware store. I cut the tip off to make it 5 feet (Because, the loop as I configured it is 4 meters circumference, so, 4*39.37/Pi = Diameter in inches). I then drilled a 5/16th’s inch hole through the middle of the ¾ inch PVC threaded pipe I had from a previous project and fit the fiberglass stick through it as the crossbar. This is a special PVC 4 foot nipple pipe I had special ordered a long time ago when mounting a previous (heavy) Ferrite-Sleeve loop antenna.

Loop Mounting

Screwed onto both ends of the 4 foot nipple are threaded-to-coupler adapters also found at the hardware store. The adapter allows me to attach easily to the ¾ inch 5 foot long PVC pipe held by my trusty carbon fiber tripod below. This 5 foot pipe is held loosely by the tripod so I can grab the pipe and turn the whole loop mounted above. The result is not perfectly circular and there is room for improvement. I find it to be highly directional nonetheless and easy to turn. The phasing connector of the YouLoop mounts at the top and for now I am just using two medium sized cable ties to a long screw near the top for tension. I do not want to glue the connector to the top since this YouLoop may get used in other configurations in the future.

The Bottom connector for the radio input is held nicely with a couple of velcro wraps.

The wire from there goes to the usual setup of Palstar amplified preselector with battery pack and Airspy HF+, which goes into the USB port on the small Dell laptop. After some initial problems with a non-functioning HF+ and rebooting a few times, I was finally able to get a signal. At first I thought it was the antenna but the error condition acted the same way whether the antenna was connected or not. It could be that my HF+ is starting to exhibit the first signs of failure, which I have read about from complaints on the internet about the reliability of SDR’s used in the field. I may have to bring along my SDRPlay SDR2 just in case! In other words, don’t depend on computer hardware and software to work (especially if you happen to go on vacation and have no backup radio!!). I also have a couple of portable non-SDR radios I could bring with me as well. Enough said.

Using It

The screen of the laptop shows a very nice black background, very quiet, and a moderate signal level of WRMI on the 31 meter band. I did not have the time or processing power for real Data captures, so all I have to share are less optimal MP3 files. The signal level is somewhat low. I think this is typical for a single-wire loop antenna and seems adequate. I did have to crank my Palstar preamp to maximum the whole time while on shortwave (my Wellbrook amp would probably work slightly better). On mediumwave, the gain seemed more than adequate (I don’t have any recordings of that band at this time, maybe a future article).

Directionality is very good and usable across a very wide range of frequencies! It certainly worked well up to the 25 meter band where I started to notice a drop off of nulling ability. And this is good despite my lack of perfect circular mounting of the wire. Even though my county park is a “Forest Preserve” and not meant to have any development, there is increasing noise in the neighborhood and I find the loop to be very useful in cleaning up some background noise (as well as noise coming from the laptop!). This is especially seen with the Voice of Iran broadcast in French. The weak signal was aided by moving the loop to balance the signal level to local noise.

The loop is a bit flimsy using it this large. Keeping the connectors tight may be a problem in the future if subject to a lot of wind. I think you will find the smaller (usual) setup in the instructions to be less of a problem. My plastic clips at the sides of the crossbar and the plastic tie downs at the top are not optimal and will need something better (in other words, it would help if I had a better mounting for the wires). Also, the tripod definitely wanted to tip over as a storm blew past, so I need to make sure I tie down one or more legs to the picnic table in the future!!

Final Thoughts

In summary, this is a very useful loop for portable operations since it fits easily into a backpack. Mounting it in a repeatable manner will need some experimentation. Performance is good with usable nulling at a wide range of frequencies. Signal strength is moderate, so a good preamp is necessary in order to boost the signal into the sweet spot of your receiver RF stage. Parts quality is good, but the wire is thin solid conductor, so do not kink/fold it!. The connectors and housing for the phase change and balun are very small, with non-waterproof plastic housings that can be easily abused, so take care of them. The whole kit is small to pack and lends itself to experimentation. Highly recommended given its limitations.

Furthermore, I feel my old, original 14-inch “crossed-parallel loop” did as good a job as this larger diameter YouLoop. I wonder how the YouLoop can be modified to create a larger gain using, say, two or more wires in parallel (perhaps a future article!)? Generally, the deeper the loop design, the higher the gain. The YouLoop potentially could be a better performing, more portable version if I can replicate using more turns of wire. Although it is in disrepair now, pictures of my old 14-inch loop are found here, and also here.

Sample Recordings

Here are a bunch of sample recordings to enjoy, some of which are unique to shortwave radio and found no where else:

9830 kHz, Voice of Turkey

10000 kHz, WWV

9395 kHz, WRMI

9420 kHz, Voice of Greece

11760 kHz, Radio Habana Cuba

11780 kHz, Radio Nacional Brazilia

11940 kHz, Radio Nationale Espana

7193 kHz, W3M – special Amateur Radio event to celebrate the birthplace of Memorial Day (Boalsburg, Pennsylvania)

7230 kHz, Voice of Iran (French)

7315 kHz, Voice of Vietnam, from WHRI-1 transmitter

7350 kHz, Radio China International, in English from Kashi PRC

7375 kHz, Radio Romania booming in from Romania

7490 kHz, WBCQ (Spanish) from Monticello ME (guide says only 50 kw but sounded more than that)

6180 kHz, Radio Nacional Brazilia

6070 kHz, CFRX Toronto – discussion about some people with ashes of relatives in the home

6115 kHz, WWCR Nashville TN – discussion about Jesus saving a young woman from Satanic ritual abuse as a child

5850 kHz, Radio Slovakia International from WRMI booming in as usual

73’s & Happy Listening,

TomL

Thank you, Tom, for sharing your field-portable SDR setup! I like how you’ve made an inexpensive and packable support system for the larger diameter YouLoop. While I’ve yet to design a similar system around the YouLoop, I really should. I’ve always believed that for both SWL and ham radio field-portable operations, a self-supporting antenna system is a must as it gives you ultimate flexibility to cope with variable site conditions.

Click here to check out Tom’s previous guest posts and portable adventures!

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Soviet era Kerosene Lamp Generator gives new meaning to “Let’s fire up the radio!”

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Many thanks to SWLing Post contributor, David Day, who recently shares the newspaper clipping above.

I was not aware of this Cold War era kerosene lamp generator, but it’s an ingenious use of the thermoelectric effect for power generation. I found yet another another clipping online:

Devices that work off of thermoelectric effect have been around many decades.

The original BioLite stove burns twigs/sticks to recharge USB devices with 3 watts of power.

I’ve often thought about purchasing a BioLite camp stove–the same one Anil Raj mentioned in our Radio Challenge II–as a companion to charge devices while camping off-grid.

BioLite now makes a more efficient (albeit pricier) stove that produces more power with less fuel.

At the end of the day, I find it so easy to use solar power to recharge larger LiFePo batteries, I’ve never invested in the BioLite.

With one large LiFePo battery, I’m able to power multiple devices including an inverter if necessary.

I’m very curious how many models of kerosene lamp generators were made back in the day and how useful they were for powering other low-drain devices.

Please comment if you’ve ever used a kerosene generator. We have readers from across the globe, so I imagine someone may have at least seen one of these in person and potentially used it to power a radio!

Oh, and obviously I need to think up another SWLing Post Radio Challenge–it’s been ages since our last!

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Spectres of Shortwave: Streaming free online May 26 – June 1, 2020

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Many thanks to Amanda Dawn Christie, who notes that Spectres of Shortwave is once again viewable online:

Hi Thomas, the [Spectres of Shortwave] video is freely viewable online for a week now. The link just went live this week, hosted by Daziabo gallery… feel free to share!

It will be freely available to stream from 10am May 26 – 6pm June 1 on this site:

https://en.dazibao.art/online

Thank you Amanda!

My apologies to those of you who tried viewing the film online from a link in a previous post. Though it was shared widely, it turns out that link wasn’t meant to be public yet. Apologies for that!

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Guest Post: KK5JY’s Porch Loop Receiving Antenna

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Can you spot the antenna in this photo?

Many thanks to Matt Roberts (KK5JY) who has kindly given me permission to re-post the following article he recently published on his website KK5JY.net. Many thanks to SWLing Post contributor, Grayhat, for the tip!

Note: The Porch Loop project below is a re-configured Small Receiving Loop (SRL) antenna. For SRL construction details, check out Matt’s primer.

The Porch Loop

by Matt Roberts (KK5JY)

The small receiving loop, or SRL, is a versatile, effective, and very space-efficient receive-optimized antenna for the HF bands. They are easy to build, and can be made very inexpensively. Most typical designs use symmetric shapes, like circles, diamonds, octagons, etc., and are mounted on some kind of mast. This makes it easy(-ier) to install the antenna clear of nearby metal and electronics. It also makes the antenna rotatable, so that the nulls can be pointed at RFI sources.

These aren’t the only options for the SRL, however. These little loops can be made to fit in just about any available space. In fact:

They are effective at any reasonable installation height, including very close to the ground. The installation height doesn’t change the pattern shape, only the pattern strength.
They can be made nearly any shape. The shape does not have to be symmetric about any axis or combination of axes.
They can be fed at just about any point on the loop. A typical feed location is bottom-center, but off-center feeding has negligible effect on the pattern shape.
The wire can be bent out-of-plane; in other words, the loop doesn’t have to be “flat.”

There are a couple of requirements for obtaining predictable performance, however. First, the antenna does need to be an electrical loop. That is, it is a single wire connected between the conductors of the feedline, forming a complete circuit. Also, the circumference of the loop wire should be electrically small (i.e., significantly less than ? / 4) on the bands where it is to be used.

Figure 1. The antenna location (click to enlarge)

As a personal challenge, I recently installed such a loop on my front porch. Everything about this installation defies conventional wisdom — it was installed very close to the ground, it was an irregular shape, it was fed off-center, and the wire was wound in and around an irregular support structure, rather having all the wire in a single plane.

And the resulting antenna still performed very well.

Figure 2: Antenna Location Outlined in Red (click to enlarge)

The loop is essentially the same device as the one in the original SRL article. See that article for more construction details. This version is simply stretched and twisted to make it fit the space and supports available. The wire was woven around the boards in the porch’s deck rail, and fed off to one side, so that the transformer housing could be “hidden” behind the trash cans.

Figure 3: Feedpoint Transformer (click to enlarge)

The wire was insulated with an off-white THHN, which made it blend in with the color of the trim of the house.

Figure 4: 40m Reception 10h Overnight (click to enlarge)

Even with its suboptimal installation details, the overnight 40m DX spots were numerous and well-distributed, as seen in Figure 4. There were DX spots at nearly 10,000 miles, there were NVIS spots, and there were countless at all distances in between. So the antenna was just as effective as its more ideally shaped brethren, despite it’s unconventional installation details.

Other ideas for possible locations of such a device could include:

In an attic. The antenna could be nailed to a vertical panel, or strung like a spider’s web inside the frame of a truss or other open area.
Under a tree. Taking another idea from the spiders, the antenna could be hung and pulled into shape using light guys or tree branches.
On a wooden fence. If you have a wooden fence, the antenna could be installed against the fence panels. This option could allow a wide range of circumference lengths.
Attached to an interior wall of an apartment. The shape could be chosen to keep the loop clear of in-wall wiring, to help preserve its performance.

The original mast-mounted SRL antennas still have some advantages. Perhaps the biggest advantage is that they can be easily rotated to null out a nearby strong noise source. That said, if you are looking for an antenna with better receive performance than a large resonant vertical, the SRL can be stretched and squeezed into service just about anywhere.

Many thanks for sharing this project, Matt! So many of our readers live in situations where they are forced to use stealthy and compromised antennas. What I love about your porch loop is that even though it breaks several loop antennas “rules,” it’s still amazingly effective.

I encourage SWLing Post readers to check out Matt’s website as he has written articles covering a number of interesting radio and antenna projects.

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New SDRply Raspberry Pi image supports the RSPdx and RDPduo

Let’s take a deep dive into a list of our favorite radios!

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Over the past week, I asked the SWLing Post community if they’ve ever regretting parting with a radio, and then what radios they’ve owned that had the most “fun” factor.

The response from these two posts was pretty overwhelming.

I don’t actually check the SWLing Post viewer stats that often, but I was too curious: together, those two posts amounted to well over 20,000 unique pageviews in two days!

Obviously, I’m not the only radio nostalgic person around here!

These posts resonated so well, I didn’t want readers’ favorite models to be lost in the comments section. I decided to comb through the comments, make a list of all of the models, and link to sites and pages with more information and photos.

This is an interesting collection of radios since some are benchmark performers, while others much less so. Many were listeners’ first radios–the ones we cut our teeth on.

I would encourage you to read through the comments on our first and our second posts. Many great memories in there!

Below, you’ll find the full list of radios in alphabetical order, starting with receivers then moving to transceivers:

Receivers

AOR 7030

AOR AR8000

Drake 2-C (Photo: Eric McFadden)

Hallicrafters SX-100 (Photo: Rick Post)

JRC NRD-515

Kaito KA1103/Degen DE1103

Realistic DX-394 (Photo: RigPix)

Realistic DX-394

Realistic Patrolman 6

Realistic Patrolman 9

Sangean 803A/Realistic DX-440

Siemens Radio E309

Sony Earth Orbiter (CRF-5090)

Sony ICF-2001D

Sony ICF-SW1000T (Photo: Universal Radio)

Sony ICF-SW7600GR

Wireless Set No.19 Mk III

Transceivers/Transmitters

Heathkit HW-8 (Photo: Eric McFadden)

The Icom IC-735

National NCX-3 (Photo: Universal Radio)

Many thanks to everyone who shared their favorite radios! I truly enjoyed checking out each of these models as I listed and linked to them. There were a number of unique models I had never seen before and many I had completely forgotten (like the Sony ICF-SW1000T)!

If you have more favorite models to share, feel free to comment here or on the original posts!

Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

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Radio Waves: Free Magazine from URE, C-19 Effect on Listening, Ampegon Focuses on Transmitters, and EU Directive for Car Digital Radio

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(Source: Ampegon)

Radio Waves: Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers. To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Mike, Paul Evans, Josh Shepperd, and Mike Terry for the following tips:

Spain’s URE makes June magazine PDF available (Southgate ARC)

In response to the ongoing Coronvirus situation Spain’s national amateur radio society URE is allowing everyone to download the PDF of the June edition of their magazine Radioaficionados

A translation of the announcement on the URE site says:

One more month, and we have already been three, with the aim of accompanying its readers in the exceptional situation caused by the spread of COVID-19, the URE in its commitment to collaborate and help to cope with the complicated situation we are currently experiencing in our country, has decided to offer free access to the magazine of the month of June and we remind you that magazines prior to December 2019 are also available to you. In this way, citizens who wish to can read these publications for free.

A small gesture so that nobody feels alone at home in the face of this global challenge.

Access is through the website download area, click on “Descargas” under “Junio 2020 – Revista” at:
https://www.ure.es/descargas/

URE in Google English
https://tinyurl.com/SpainURE

Ampegon Puts Focus on Shortwave Transmitters (Radio World)

Ampegon Power Electronics highlights progress on the company’s third-generation solid-state shortwave transmitters, which it says will offer “significant advances in efficiency.”

The company says this work will pave the way toward higher-power broadcast outputs and meet current expectations of a shortwave equivalent to medium-wave and FM transmitters. “Combined, these two developments will bring FM-quality broadcasts with all the benefits of shortwave,” said Simon Keens, Ampegon sales and business development manager.

Ampegon has also developed a retrofit upgrade to current UCS generation control systems for previous generation 100 kW, 250 kW, 300 kW and 500 kW transmitter systems.[…]

Listening together, listening alone: A music professor sounds off on his shifting industries (CBC)

Brian Fauteux reflects on the way COVID-19 is affecting his two passions: music and teaching

A lot of great songs effectively reflect the feelings that accompany isolation. The experience of being alone, however, is often constructed in opposition to a longing for togetherness. Heart’s “Alone” (1987) — maybe the greatest power ballad ever recorded — confidently asserts, “‘Til now I always got by on my own.” But this is no longer the case when the song’s protagonist meets and develops undeniable feelings for another: “And now it chills me to the bone.” In another iconic 80s anthem, “Dancing in the Dark,” Springsteen grows tired and bored with himself against the desperate urge to join up with “something happening somewhere.” The act of dancing in the dark can be fun, sure, but it’s much more fun with others. Inspiration in isolation is insubstantial.

I’m an Assistant Professor of Popular Music and Media Studies, and I teach and write about the role of music in society. I’m interested in how our listening practices shape, and are shaped by, issues of sustainability in the music industries — that is, how artists make (or struggle to make) a living in this day and age.[…]

EU directive on digital radio in cars (Times of Malta)

Directive (EU) 2018/1972 of the European Parliament and of the Council of December 11, 2018, establishing the European Electronic Communications Code (‘EECC’) entered into force on December 20, 2018. Member states have two years to incorporate it into national law, except where specifically mentioned.

Radio is an important medium through which citizens access a diverse range of information news and entertainment services. The EECC leverages on the ever-increasing connectivity of new generation cars as well as on the digital platforms of radio broadcasters to guarantee a more robust radio experience to all drivers, ensuring good coverage, a wider choice of radio stations and more effective access to information at all times. The EECC ensures that car drivers have access to the benefits of digital terrestrial radio wherever in the EU they have bought their new car.

On April 21, the minister responsible for communications, in consultation with the Malta Communications Authority, published Legal Notice 151 of 2020 amending the Electronic Communications Network and Services (General) Regulations, implementing the provision of the EECC dealing with the interoperability of car radio devices. In line with the regulation, any car radio receiver integrated in a new vehicle of category M which is made available on the market for sale or rent in Malta from December 21, 2020, shall comprise a receiver capable of receiving and reproducing at least radio services provided by digital terrestrial radio broadcasting of type DAB+. Radio programmes in Malta are broadcast terrestrially on DAB+.

The car radio requirement only applies to new cars.[…]