Author Archives: Guy Atkins

What’s Up with the XHDATA D-808 Availability in the USA?

After the initial flurry of reports, interest, and purchases of the XHDATA D-808 portable receiver by radio enthusiasts, the door on USA shipments seems to have slammed shut.

This fine DSP-based portable went live in early December 2017 for USA purchasers when it was offered by AliExpress for $69.98 with shipping. Later, the RadiWow site started selling the radio for nearly the same price including USA shipping.

Now in mid-March 2018, the D-808 is nowhere to be found on AliExpress:

Sure, the RadiWow firm still ships the D-808 to the USA, but for a ridiculous “we don’t really want your business anyway” price. (A company that has a product page with “LOGO” in the corner is certainly not paying attention…perhaps they meant to enter “USD $20” as the cost? :^)

My hope is that XHDATA is working on an exclusive USA distributorship, such as Kaito Electronics Inc. has in this country for Kaito radios, or perhaps the D-808 will eventually be found only on Amazon USA. Maybe the highly regarded EBay seller Anon-Co (Anna) is at work behind the scene to offer this model exclusively.

What’s going on here? Please leave your thoughts in the comments section below.


Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

Popular SDR-Console V3 Software Moves from Preview to Beta

Simon Brown, G4ELI’s widely used, free SDR-Console V3 was upgraded from “Preview” to “Beta 1” level today. Many SDR enthusiasts have waited for this next step; even in Preview form, Version 3 has performed nearly as well as a production release in many ways.

I have briefly used SDR-Console (V2 and V3) off and on for a few years, but it wasn’t until acquiring AirSpy HF+ receivers that I took a serious plunge into V3. Now that I’ve gone through its modest learning curve, I like this SDR software quite a bit!

There are many things I enjoy about SDR-Console, not the least is the power and ease of use of the Recording Scheduler, a feature that’s important to medium wave DXers. I’m sure others who like to set up unattended WAV I/Q recordings for later review benefit from this also.

I’ve not found a list of improvements between Preview and Beta 1, but I suspect Simon has made the upgrade because the Preview has shown itself to be quite stable already. He did publish a list of a few known bugs:

  • External Radio using IF output does not work.
  • Remote Server using the SDR-IQ has stutter.
  • Kits are not signed – a code signing certificate has been purchased from Comodo but is not yet available.

Simon indicates that these bugs will be worked on in the next few weeks.

If you use and benefit from SDR-Console software, please considering support the development efforts through a PayPal donation. Links to download the newest Beta 1 version, and/or to donate, can be found here: http://www.sdr-radio.com/Downloads

Here are a couple YouTube videos which show SDR-Console V3 (Preview build) in action:

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

Results: AirSpy HF+ vs Elad FDM-S2 Weak Signal Comparisions

Looking north toward Cape Lookout, Oregon, near the site of my SDR receiver recordings. Photo courtesy of Wikimedia Commons.
In my original article 10 days ago, I set up a SWLing Post reader poll to let you give your opinion on which shortwave recordings within four pairs of audio files provided the most intelligible result. The recordings were intentionally noisy, low-level signals to help us discover–through critical listening to the files–if there is a clear favorite between the AirSpy HF+ or the Elad FDM-S2 receivers. Of course, there were only four pairs of recordings…not a very large sample size.

However, 34 readers of the original article took the time to listen and respond, so let’s get to the numbers, shown in these graphs:

Interestingly, the responses above seem to point to:

  • Two recording pairs tied in the results (50% / 50%) or were very close (HF+ 52.9% / FDM-S2 47.1%)
  • The FDM-S2 led one recording pair by a large margin (67.6% / 32.4%)
  • The HF+ led another recording pair by an equally large margin (67.6% / 32.4%)

Taken as a whole, no obvious winner emerged, although one might conclude the HF+ has a slight edge due to its lead in the “very close” recording pair of 7.230 MHz.

One thing is clear–the AirSpy HF+ is a surprisingly good performer for its price of $199 USD! For many enthusiasts this will be all the SDR they need.

As a final note, I’ll mention that the AirSpy HF+ used for the tests was totally stock. I have not yet performed the “R3 Bypass” mod nor the firmware update to my HF+ units. The simple R3 Bypass, discussed at length on the AirSpy Groups.io forum, significantly boosts sensitivity of the HF+ from longwave up to about 15 MHz, without any noted overload issues. For more on this modification from a MW DXer’s perspective, read Bjarne Mjelde’s insightful article at his Arctic DX Blog.

Thank you to all the readers who took the time to listen to the SDR recordings in this comparision and register your opinions.

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

Digging in the Noise: Weak Signal Audio Recovery with the AirSpy HF+ and Elad FDM-S2

I’m currently spending the better part of a week at Cape Lookout State Park on the Oregon coast, with a great view of the ocean through tall evergreen trees. This is one of my favorite parks in the Pacific Northwest, especially when DXing during the blustery winters from one of the nice cabins at Cape Lookout.

The view from the beach near my cabin; the turbulent waves were a precursor to the gale force winds at the park during the night of the 23rd!

Although I’m at the park for trans-Pacific medium wave DXing, I’m also comparing receivers, both SDRs and portables. This morning I sought out a few weak shortwave signals, pitting the Elad FDM-S2 SDR ($529 USD) against the AirSpy HF+ ($199 USD). I have a pair of the HF+ receivers to cover all of medium wave (as the FDM-S2 easily does). Many SWLing Post readers already know that the upstart HF+ trades bandwidth to gain high performance in order to keep the price reasonable.

My antenna used for the following recordings was a small “Flag” antenna using a Wellbrook Communications FLG100LN module and a 2K ohm variable potentiometer for termination. The design uses crossed tent poles in an “X” formation to support the wire loop. This design travels easily in a compact package; I have Dave Aichelman of Grants Pass, Oregon to thank for this very useful “tent pole loop” implementation of the Wellbrook FLG100LN.

The Wellbrook-based antenna functions superbly, and its low-noise design helps hold down QRM from the nearby cabins (which unfortunately have been “upgraded” recently with noisy cold fluorescent [CFL] light bulbs). The area around the Cape Lookout cabins used to be superbly low noise and suitable for radio listening, but now it is more of a challenge than before. The Wellbrook FLG100LN is perfect for the situation though; Wellbrook ALA1530LN  Pro and ALA1530S+ 1-meter loop antennas work commendably at the park too.

The Wellbrook FLG100LN module with a home brew RFI choke in-line

A 2K ohm variable potentiometer is protected from the elements in a small plastic bag. The “pot” is adjusted for the best nulling of medium wave stations off the back side of the antenna’s reception pattern.

The “tent pole loop” antenna is strapped to a fence railing with ultra-strong Gorilla Tape to keep the 7-ft. square loop vertical.

On with the recordings…

For the FDM-S2 and HF+ comparisons I used the SDR-Console V3 software. Every parameter was identical for the receivers–sampling bandwidth, filter bandwidth, AGC, mode and so on.

Take a critical listen to the weak signals recorded with the SDR receivers, identified as only “Radio A” and “Radio B”. A link to a poll is at the end of this article; please indicate which recording of each pair has the most intelligible audio in your opinion, and submit your choices when you’ve made up your mind on each audio clip. After a week or so I’ll post the results of the voting, and identify the receivers.

9.615 MHz, LSB, Radio A


9.615 MHz, LSB, 
Radio B (note: the same male announcer heard in clip “A” begins at 00:14 in this “B” clip)

 

9.730 MHz, USB, Radio A


9.730 MHz, USB, 
Radio B

 

7.230 MHz, S-AM, Radio A


7.230 MHz, S-AM, 
Radio B

 

9.860 MHz, S-AM, Radio A


9.860 MHz, S-AM, 
Radio  B

 

Note on 7.230 MHz recording: this was an interesting frequency, as the signal was tightly surrounded by a very strong local 40m ham radio LSB station as well as a strong China Radio International signal. There were other strong amateur and broadcast stations within 30-50 kHz of 7.230 MHz, also. This A-B test more than the others may indicate receiver performance in a strong RF environment on a crowded band.

Ready for the poll? Register your votes at the Google Docs form below:

https://tinyurl.com/ya38wj69

In a week to 10 days I’ll post the results in another article. NOTE: I haven’t provided a “both sound the same” choice in the poll to encourage you to ‘dig deep’ into the audio and listen critically–to find something that stands out in one clip versus the other.

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

XHDATA D-808: A Shortwave Comparison Against Four Other Portables

When the clouds part and the sun shines during the winter in the Seattle, Washington area, it’s time for a celebration! I decided to take advantage of the mild weather and compare the XDATA D-808 (a real upstart in the marketplace, and a value leader in portables) against a few other radios on a nice daytime signal from Radio New Zealand International, 15720 kHz.

Besides the D-808, receivers compared to each other were: the C. Crane Skywave SSB (complete with stray cat’s whisker on the LCD :^) , the Eton Executive Satellit, the Grundig G3, and a beautiful example of the rare Sony ICF-SW1000T (sometimes called the Sony Shortwave Walkman due to the built-in cassette recorder). My apologies for the lower audio setting on the G3.

The antenna used with each radio was a PK Loops “Ham Loop” antenna, which is advertised as covering 3.5 – 14.5 MHz, but my loop actually tunes approximately 3.2 MHz to 15.8 MHz. I also briefly received RNZI on each radio’s own whip antenna.

I used the 3.0 kHz bandwidth on all the SiLabs DSP radios, and the narrow filter on the G3. The ICF-SW1000T has a single filter, so it cannot be adjusted.

Since the G3 and the ICF-SW1000T have the option of synchronous-AM detection, in the video I cycle through those modes on these receivers.

RNZI on their 15720 kHz frequency is often at a good, program listening level in my local afternoons. Next week I plan to seek out and share videos of the D-808 with weak DX signals from an RF-quiet location on the Oregon coast.

Which receiver sounds the best to you with the external antenna, and which one shines with its own whip aerial? Please share your thoughts in the comments below.


Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.