Category Archives: Guest Posts

Guest Post: Dan’s letter concerning the new Elite Satellit

Many thanks to SWLing Post contributor, Dan Robinson, who publishes the following guest post:

Letter to Eton: Cutting Corners on Elite Satellit Won’t Succeed

by Dan Robinson

As SWLing.com readers will recall, weeks before Eton shipped the first group of Elite Satellit receivers I published a commentary that asked a key question: would Eton be able to meet the higher standards of the listening community in 2022 when it comes to new advanced portables?

Unfortunately, we all see what the answer to that question was. Eton was forced to recall Elite Satellit radios that had been shipped to major resellers such as Universal Radio, Ham Radio Outlet, and others as defects became all too apparent.

A radio that had been on its way to me for review was among those recalled. But I recently was able to examine a unit that a friend in the Washington, DC area purchased. What I found I am putting in this commentary as a letter to Eton.

If the company takes these points seriously, I think there is still hope that the Elite Satellit can join the ranks of respectable multi-band portables – after Eton has gone back to the drawing board so to speak. However, if Eton continues to cut corners with this receiver, its future is not bright:

Letter to Eton on the Elite Satellit

Dear Eton,

MUTING WHILE TUNING

As many who purchased or tested the Elite Satellit have remarked, the fact that you decided to release a radio with this issue is beyond comprehension. Tuning on the Elite Satellit is, tragically, an uncomfortable and frustrating experience. This needs to be corrected/fixed – you only need to take a look at Tecsun receivers such as the H-501 or PL-990x to know what needs to be done.

POORLY-IMPLEMENTED PASSBAND TUNING

Perhaps even more puzzling than muting, the Elite Satellit I tested had an even more mind-boggling issue. Passband tuning should function to adjust the signal pitch without changing the audio frequency. On the radio I tested, PBT was actually TUNING and changing the frequency. Using PBT on this radio was virtually no different from tuning in SSB, with injected tones heard, until a zero beat was achieved. All you had to do was take a look at a E1 receiver, or any other receiver with well-implemented PBT to understand how real PBT is supposed to function.

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Small Unidirectional Loop Antenna (SULA) Part 2: Construction Notes

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Many thanks to SWLing Post contributor extraordinaire, 13dka, who brings us Part Two of a three part series about the new SULA homebrew antenna project. This first article describes this affordable antenna and demonstrates its unique reception properties. This second article focuses on construction notes. The third and final article will essentially be a Q&A about the SULA antenna. All articles will eventually link to each other once published.

This wideband unidirectional antenna is an outstanding and innovative development for the portable DXer. I love the fact that it came to fruition via a collaboration between Grayhat and 13dka: two amazing gents and radio ambassadors on our SWLing.net discussion board and here on the SWLing Post. So many thanks to both of them!

Please enjoy and share Part 2:

Part 2: SULA Construction notes

by 13dka

The drawing [above] has all you need to know. You basically need to put up a symmetrical wire diamond starting with a balun at the one end and terminating in a resistor at the other end of the horizontal boom, the sides are supposed to be 76cm/29.92″ long so you need to make yourself some…

Support structure:

I used 0.63″/1.6cm square plastic square tubing/cable duct profiles from the home improvement market to make the support structure. You can use anything non-conductive for that of course, broom sticks, lathes… The plastic profiles I used had the advantage of being in the house and easy to work on with a Dremel-style tool and everything can be assembled using the same self-tapping screws without even drilling. The profiles are held together with 2 screws, for transport I unscrew one of them and put that into an extra “parking” screw hole on the side, then I can collapse the cross for easy fit into the trunk, a rucksack etc.

These profiles are available in different diameters that fit into each other like a telescoping whip. This is useful to make the support structure variable for experiments and to control the loop shape and tension on the wire. The booms end up at 1.075m each, the profiles come in 1m length, so that’s 4 short pieces of the smaller size tube to extend the main booms by 37mm on each side

On the resistor end of the loop that smaller tube isn’t mounted in the “boom” tube but to the side of it in order to keep the wire running straight from the balun box on the other side.

Mast/mounting:

You can use anything non-conductive to bring it up to height. On second thought that is indeed bad news if you were planning on putting that up on your metal mast…and we have no data on what happens when you do it anyway. I don’t know if the smallest (4m) telescoping fiberglass poles would suffice for portable operation, but I’m a fan of just using the big lower segments of my 10m “HD” mast for the stiffness they give me (3 segments for the height, the 4th collapsed into in the base segment for easy rotation). Telescoping masts also give you easy control over…

Height:

The published patterns are for 3m/10′ feedpoint height over “average” ground. Increasing height further has no expectable advantage, instead it will deteriorate the favorable directional pattern of the loop. Flying it lower, or even a lot lower in windy weather on the other hand is causing a surprisingly moderate hit on performance.

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Introducing the amazing SULA: An affordable unidirectional DX-grade loop antenna that you can build!

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Many thanks to SWLing Post contributor extraordinaire, 13dka, who brings us a three part series about the new SULA homebrew antenna project. This first article describes this affordable antenna and demonstrates its unique reception properties. The second article will focus on construction notes. The third and final article will essentially be a Q&A about the SULA antenna. All articles will eventually link to each other once published.

This wideband unidirectional antenna is an outstanding and innovative development for the portable DXer. I love the fact that it came to fruition via a collaboration between Grayhat and 13dka: two amazing gents and radio ambassadors on our SWLing.net discussion board and here on the SWLing Post. So many thanks to both of them!

Please enjoy and share SULA Part 1:

Introducing the Small Unidirectional Loop Antenna (SULA) 1-30MHz

A small and simple, unidirectional and DX-capable loop “beam” for SWLs!

by 13dka

In early June, Andrew (grayhat), SWLing Post‘s resident antenna wizard suggested a variation of the “cardioid loop” on the SWLing Post message board: The original “cardioid loop” is a small loop receiving antenna deriving its name from a cardioid shaped (unidirectional) radiation footprint. The design is strikingly simple but it has a few downsides: It relies on a custom preamp, it needs a ground rod to work and it is unidirectional only up to 8 MHz.

Andrew’s version had the components all shuffled around and it did not only lose the ground rod, it also promised a nice cardioid pattern over the entire shortwave, from a small, diamond shaped loop. Wait…what? It can be made using parts available on Amazon and your DIY store:

You need some 3m wire and PVC tubes to create a support structure to hold the wire, a 530 Ohm resistor and a 9:1 balun like the popular “NooElec One Nine”. Since it’s a “lossy” design, adding a generic LNA like the NooElec “LANA HF” would help getting most out of it. When you put that all together you have what sounds like an old shortwave listener’s dream: a small, portable, tangible, and completely practical allband shortwave reception beam antenna with some more convenient properties on top, for example, it is a bit afraid of heights.

That sounded both interesting and plain crazy, but the .nec files Andrew posted were clearly saying that this antenna is a thing now. Unfortunately Andrew suffered a little injury that kept him from making one of those right away, I on the other hand had almost all the needed parts in a drawer so I ended up making a prototype and putting it through some of its paces, with Andrew changing the design and me changing the actual antenna accordingly, then mounting it upside down. Let me show you around:

Small, diamond shaped wire loop (with 76cm/29.92″ sides), needing as little space as most other small loops.
Unidirectional with a ~160° wide “beam” and one pronounced minimum with a front/back-ratio of typically 20dB over the entire reception range 1-30MHz.
Moderate height requirements: It works best up to 3m/10′ above ground, where it gives you…
…a main lobe with a convenient flat takeoff angle for DX
Antenna is comparatively insensitive to ground quality/conductivity.
Wideband design, works best on shortwave and is pretty good up to 70cm.

A functional small beam antenna for shortwave reception that’s just as small and possibly even more lightweight (prototype:~250g/9oz) than your regular SML, that can be easily made out of easy to obtain parts and easily carried around for mobile/portable DXing and due to its cardioid shaped directional pattern also for direction finding, a “tactical” antenna that’s also doing DX? Unlike conventional, Yagi-Uda or wire beams it can achieve a low takeoff angle at only 3m/10ft height or less, the front/back ratio is typically better than that of a 3-element Yagi, with a particularly useful horizontal pattern shape. That it’s rather indifferent to soil quality could mean that more people get to reproduce the good results and being a real wideband antenna is making the SULA an interesting companion for multiband radios and SDRs. Really? A miracle antenna? Is it that time of year again? If I had a dollar for every….

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A case of WTAB déjà vu

Further adventures of WELK

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Hi to all SWLing Post community, it’s Fastradioburst23 again letting you know about the second transmission of WELK this evening at 2200 utc on 9395 kHz thanks to the good folks at WRMI.

If you enjoyed all the accordion and squeezebox based tunes last week you’ll be sure to love this second installment and it’ll be a good one to have on in the background whilst perfecting those air accordion moves.

Alexander shares a few photos and notes from Hamradio 2022 in Friedrichshafen

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Many thanks to SWLing Post contributor, Alexander (DL4NO), who shares the following photos and notes from Friedrichshafen:

First Hamradio After Two Years

Alexander (DL4NO)

Finally the biggest amateur radio event in Europe happened again: Last weekend hams from Germany, Austria, Switzerland, France, Italy, Poland, Belgium, Netherlands, GB and more gathered in Friedrichshafen. The location is quite attractive, in Germany but near Austria and Switzerland. I could not get any numbers yet. But the event was quite a bit smaller than in 2017 when I was there the last time.

As every year amateur radio societies from Europe and the ARRL had booths. The most remarkable was from the Austrian OeVSV with their own stage. They had their own, quite interesting lectures. For example Austrian Hams have used the geostationary satellite QO-100 for LoRa experiments. They are quite active with LoRa as this technology allows to transmit data quite slowly, but quite far and with a minimum of power. Their project is called MeshCom. Continue reading →

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!