Category Archives: New Products

New Product: K-180WLA Active Loop Antenna with rechargeable battery

Many thanks to SWLing Post contributor, crvee8, who shares a link to the K-180WLA, a new active mag loop antenna.

Based on the product description, the K-180WLA sounds a lot like a typical magnetic loop antenna (and resembles the popular MLA-30), but what makes it unique is the fact that it can be recharged via a Micro USB port.

This means, there’s no need for a separate power supply.

There’s no mention of how long a charged battery would power the amplifier, but I imagine it would be respectable given it employs the 3.7V 18650 lithium cell.

The frequency range is 0.1-180 MHz and the manufacturer claims it, “provides a gain of about 20 dB, even when working to 450MHz gain, there is still about 8.9 dB.”

Battery power would certainly make this a very portable active antenna loop option. The price is right, too, at $55.88 USD which includes shipping from China. The listing claims only 5 units are available at time of posting.

Click here to view on eBay (partner link).

Post readers: Please comment if you’ve purchased this antenna. We’d love to hear your thoughts/review.

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Icom IC-705 delivery has been delayed

Many thanks to SWLing Post contributor, Paul Evans, who writes:

As you’d expect, Icom has formally delayed the delivery schedule of the IC-705.

Here’s the announcement from Icom Japan: https://www.icom.co.jp/news/4720/

The following is a machine translation of the announcement:

“Thank you very much for your patronage of ICOM products.

We have received reservations from a large number of customers about the IC-705, a 10W walkie-talkie with HF~430MHz all-mode, which was scheduled to be released in late March 2020. Some of the parts involved in the production of the product are delayed due to the new coronavirus issue, and production has been delayed due to this.

We apologize for any inconvenience caused to all of you who are looking forward to our products.

As for the delivery of the product, because it is a situation in which the arrival schedule of the part does not stand now, I will guide it separately as soon as it turns out.

We will take a while to deliver it, but we will do our best to deliver it as soon as possible, so please understand us.”

Thanks for sharing this, Paul. No doubt, delays are due to the affects of Covid-19 on both manufacturing in Japan and throughout the IC-705 supply chain.

For updates, bookmark the tag IC-705.

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The Airspy Youloop is a freaking brilliant passive loop antenna

Before I start talking Youloop, I have a little confession to make up front:

At the Winter SWL Fest when I gave a presentation about Portable SDR DXing, not only did I give attendees the wrong name of the Airspy Youloop antenna, but I also configured it incorrectly, hence the poor performance via my Miscrosoft Surface Go tablet PC.

I had assumed the the crossover component of the antenna was the transformer component. I realized the mistake I made when I saw some of the first promotional photos of the Youloop antenna a few weeks ago.

The crossover connects both sides of the loop while the tee junction contains the transformer.

Doh! I’m trying to forgive myself for making such an obvious mistake, but in my defence–and in the spirit of full disclosure–my antenna was a very early sample prototype without instructions, diagrams, etc. so I set it up imagining it being similar to the homebrew loop Vlado and I built. (FYI: When I say “Vlado and I built” it, I really mean, “Vlado built it.”) 

So obviously I made a poor assumption.

Once I assembled the antenna correctly? Wow. Just. Wow!

Youloop: The ideal travel antenna for high dynamic range SDRs

The Youloop, Airspy HF+ Discovery, SDRplay RSPdx, and all cables easily fit in my Red Oxx Lil Roy pack.

The Youloop is truly the travel antenna I’ve always wanted for portable SDR DXing. Here’s why:

  • It’s incredibly portable and can be rolled up to fit in a small travel pouch
  • It has all of the low-noise characteristics of other magnetic loop antennas
  • It’s wideband unlike many passive loop designs
  • It requires no variable capacitor or tuner
  • It’s made of quality components
  • It requires no external amplifier nor power source
  • It takes one minute to assemble
  • It’s affordable (~$35 USD shipped)

The only caveat? To take advantage of the Youloop, you must use a high dynamic range receiver.

Airspy HF+ Discovery SDR

I can verify that this antenna works brilliantly with the Airspy HF+ Discovery.

The AirSpy HF+ SDR

It will also pair well with the Airspy HF+  if you shortcut R3 via the R3 modification.

SDRplay RSPdx SDR

I’ve also used it numerous times with the new SDRplay RSPdx while using SDRuno in High Dynamic Range (HDR) mode. With the RSPdx, I can make spectrum recordings of the entire AM broadcast band. Note that HDR mode is only available on the RSPdx at 2 MHz and below, using the SDRuno app.

I have not tested the Youloop with other SDRs yet. I will soon test it with my WinRadio Excalibur.

So how well does the Youloop perform?

Listen for yourself!

I’m doing a little cargiving family members today. Their home is swimming in RFI (radio interference/noise). In the past, I’ve struggled to make good mediumwave recordings at their home–certainly an ideal situation for a mag loop antenna.

This morning, I wanted to record one of my favorite local AM stations (WAIZ at 630 kHz), so I set up the Youloop in the middle of a bedroom, hanging off a large bookshelf set against an interior wall. In other words: not an ideal situation.

When I plugged in the Airspy HF+ Discovery and loaded the Airspy SDR application, I fully expected to see a spectrum display full of broadband noise.

Instead, I saw signals. Lots of signals:

Sure, there’s some noise in there, but it’s low enough I could even do proper mediumwave DXing on most of the band if I wished.

In fact, if you’d like to experience the HF+ Discovery/Youloop pairing in this compromised, less-than-ideal DXing setup, why not tune through one of the spectrum recordings I made?

Click here to download the spectrum file [885.7MB .wav].

The recording was made on March 30, 2020 starting around 10:50 UTC. You’ll need to open this file in AirSpy’s free application SDR# or a third party SDR app that can read AirSpy .wav files.

I can’t wait to try the Youloop in other locations. Since we’re in lock-down due to Covid-19, I won’t be able to try the Youloop in a hotel any time soon. Almost all of my 2020 travel plans have been canceled.

Highly recommend

If you have one of the SDRs mentioned above, go grab a Youloop. At $35 USD, it’s a fantastic deal.

Click here to check out the YouLoop at the RTL-SDR.com store ($34.95 USD shipped).

Click here to check out the YouLoop at Airspy.US ($29.95 + shipping).

Click here to search for AirSpy distributors in your region/country.

If you don’t have a high dynamic range receiver, note that Airspy is exploring the idea of making a pre-amp for the Youloop. If interested, you might drop them a note of encouragement!

Do you have a Youloop? Please share your comments!


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AirSpy YouLoop passive magnetic loop antenna now shipping

Many thanks to SWLing Post contributor, Michael Agner (KA3JJZ), who notes that AirSpy  now has the YouLoop passive mag loop antenna posted on their retail websites.  You can grab one for $30 – $35 US, depending on your location. That’s a fantastic deal in my book.

Click here to check out the YouLoop at Airspy.com.

Click here to check out the YouLoop at Airspy.US ($29.95 + shipping).

Click here to search for other AirSpy distributors.

Note that the YouLoop only works well with high dynamic range SDRs and receivers like the AirSpy HF+ Discovery.

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Tecsun PL-990: How to distinguish pilot run and final export versions

The Tecsun PL-990

As I suspected, it appears the Tecsun PL-990 batch that showed up recently on AliExpress for $399 each are the preliminary pilot run units that Tecsun offered in China last year. The final export version of the PL-990 is not ready for production yet and has been severely delayed by Covid-19 quarantines.

Anna at Anon-Co reports that Tecsun factories have been closed since mid-January 2020 and have only recently recommenced production, “but at a very slow pace.”

Since there will eventually be two different versions of the Tecsun PL-990 in the wild–the pilot run for China, and the finalized export version–I thought I’d share a trick Anna has described to tell the difference between the two.

Anna notes:

One way to easily see this is from the labels for the buttons above the keypad, these should be

[ TIME ], [ TIMER A ], and [ TIMER B ] (see picture below)

Tecsun PL-990 Final Export Version:

Tecsun PL-990 Final Export version

Tecsun PL-990 Final Export Version

Pilot Tecsun PL-990 (preliminary China domestic version):

Preliminary Pilot Tecsun PL-990 distributed in China — image from AliExpress.

Anna adds:

I highly recommend [no one] buy these pilot versions, because the software on those devices is also not developed.

There still isn’t a final version or any price indication available yet, but it will definitely not be US$399.99.

So in case it’s not clear: don’t purchase a PL-990 until you can confirm you’re receiving a final export version which has the TIME, TIMER A, and TIMER B labels.

Again, at time of posting, the final PL-990 export version is not yet in production.

When the final export PL-990 is available, I will announce it here on the SWLing Post with links to authorized retailers like Anon-Co.

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Airspy Youloop and Homebrew Passive Loop Antenna designs

Almost two weeks ago, at the 2020 Winter SWL Fest, I gave a presentation called “A New Era in Portable SDR DXing.

The presentation was essentially an in-depth version of an article I published in the January 2020 issue of The Spectrum Monitor magazine (see cover above).

I devoted a good portion of the presentation describing how to build a passive loop antenna design by Airspy’s engineer and president, Youssef Touil. This passive mag loop takes advantage of the Airspy HF+ Discovery‘s exceptionally high dynamic range and is an impressive performer.

The homebrew loop on the balcony of a hotel.

You may recall, I posted a short article about this loop in November after enjoying a little coastal DXing.

In short? This passive loop antenna pairs beautifully with the Airspy HF+ Discovery. I’ve also been very pleased with results using the new SDRplay RSPdx on the mediumwave band where the receiver now sports a high dynamic range mode.

Overdue corrections…

After returning from the Winter SWL Fest last week, I was hit with an upper respiratory bug. No doubt, a souvenir of my travels!  It wasn’t the flu (I was tested), nor COVID-19, but it did knock me off my feet for a few days with fever, coughing, and headaches. You might have noticed a lot less posts last week and almost no replies from me via email. I’m only now feeling totally human again and trying to catch up with my backlog.

Shortly after my SWL Fest presentation, I realized I made (at least!) two mistakes. I had planned to post corrections here on the SWLing Post last week, but the bug delayed all of that, so here you go:

#1 Schematic of my homebrew passive loop antenna

When Youssef started experimenting with passive loop antenna designs, he posted a few schematics of at least three build options.

Although I described how to build my passive loop antenna, I grabbed the wrong schematic for my presentation slides. Many thanks to those attendees who noticed this.

Here is the schematic I should have shared:

Note that the transformer has four turns on both sides (the one in the presentation had 4:2).

Again, apologies for any confusion.

#2 The Airspy Youloop passive loop antenna

If you’re not inclined to build your own passive loop antenna per the diagram above, Airspy is planning to manufacture and sell a lightweight, high-performance loop of a similar design.

Prototype of the Airspy Youloop in the field (note bright blue cable jacket)

During the presentation, I called the future AirSpy antenna, the “Spytenna.” I was incorrect. (Turns out, I got this name from an early antenna schematic and somehow it stuck in my head!)

Airspy is calling their passive loop antenna the Youloop. Youssef posted the following note in the Airspy email discussion group:

We are currently arranging the shipping of the affordable passive version to Airspy.us and RTLSDR Blog.

Btw, It’s called “Youloop”

Many thanks to Richard Langley and a number of other readers who pointed this out last week.

I’ve had a prototype of the Youloop since November and brought it to the SWL Fest and presentation. It’s a quality antenna and incredibly compact when disassembled and rolled up.

When the Youloop is available to order, we’ll post links here on the SWLing Post.

More to come!

Once I catch up here at SWLing Post HQ, I plan to publish detailed construction photos of the homebrew loop antenna.

Many of you have questions about how to tap into the center conductor at the mid-point of the loop. These photos should help guide you.

Stay tuned!


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Tecsun PL-990 (pilot run) now on AliExpress

Many thanks to SWLing Post contributor, Dan Robinson, who notes that the Tecsun PL-990 has now appeared on AliExpress.com.

The price is a steep $399 US shipped via DHL with an estimated delivery of late March. They claim to have about 900 units available.

You can check out the PL-990 on the AliExpress website, but it might require registration even via this direct link.

Frankly, I would wait until the PL-990 is available at Anon-Co since they’re an authorized Tecsun distributor, have proven customer service, and will likely have a more competitive price. I would also question if the AliExpress units are the new export version we’ve been waiting for, or simply the units that were available within China last year. The AliExpress page gives us no clear indication of the production version at time of posting.

UPDATE: Turns out, these are the pilot Chinese versions of the PL-990. I can’t recommend purchasing one–especially at this price.

I hope this might indicate that the PL-990 is close to release. Covid-19 has certainly stopped much production and development in China. Thanks again for the tip, Dan!

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