The Siru Innovatios SDR20 adds new features


Many thanks to Jarkko Mäkivaara with Siru Innovations who writes with the following update:

We have added some new features to our SDR20 portable radio!

Please see the video [below] for a demonstration of the following features:
* Smooth zoom in FFT/waterfall view
* Adaptive menu
* Frequency memory with snapshot pictures of signals
* Sliding effect between views
* Keyboard beep
* FM broadcast receiver
* Example of Ham radio transceiver with Narrow-FM mode
You also might got the email sent out Today where this is in HTML format.

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Shortwave portables that are PC-programmable?


SWLing Post reader, Mark, recently contact me with the following question:

“What portable shortwave radios under $300 have an option to have their memories programmed using a computer?”

I replied to Mark that I can’t think of a single shortwave portable that can be programmed via computer–at least, not a “typical” portable radio like a Sony, Sangean, Tecsun, Degen, or Redsun.


The Yaesu VX-3R HT tuned to the AM broadcast band.

I may be wrong, however, so please comment if you can help Mark identify a model.

I am aware of portable wideband communications receivers/transceivers that cover the shortwave bands: handhelds like the Icom-IC-R6, Icom IC-R20, Yaesu VX-3R, AOR AR8200 Mark III B and Kenwood TH-F6A.

Wideband handhelds are more akin to a scanner, though, and typically shortwave sensitivity is simply not on par with a dedicated shortwave portable. The AOR AR8200 Mark III B  ($700+) and discontinued Icom IC-R20  may be a couple of exceptions.

Please comment if you can help Mark with his quest.

Posted in News, Portable Radio, Shortwave Radio | Tagged , , | 5 Comments

Peter’s archived recordings include KBC

SX-99-DialSWLing Post reader, Peter (K3KMS) writes:

In a post dated October 25, 2014, you mentioned listening to the ‘Giant Jukebox’ radio program on The Mighty KBC Shortwave.

For the past year or so, I have been a big fan of said program, and I try to listen to it every Saturday evening (0000 UTC, I’m located in Delaware). When I am able to listen, I record the program using my Drake R8B, and I archive the obtained recordings on my website.

The link to the archive web page is provided below (scroll down to the 7375 khz and 9925 khz table rows). I was hoping that you might share said link with your readership so that they, too, can experience this (in my humble opinion) awesome radio program at their leisure!

Many thanks, Peter, and I’m quite happy to share your recordings. Like you, I’m a big fan of The Mighty KBC–we’re most fortunate to have a broadcaster like KBC on the shortwaves! I look forward to checking out your other recordings as well.

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Guest Post: Richard tests the frequency stability of the Tecsun PL-880

PL-880 (1)Many thanks to SWLing Post contributor, Richard Langley, for the following guest post:

Frequency Stability of My Tecsun PL-880

Recently, while recording the audio on a particular SW frequency unattended over night, I decided to set my Tecsun PL-880 in USB mode with the 3.5 kHz RF bandwidth setting as I had previously noticed splatter QRM from a station 10 kHz below my frequency of interest. I adjusted the frequency to the nearest 10 Hz for natural-sounding voice. On playing the recording, I was disappointed to find that the signal had drifted in frequency and although speech was still recognizable, music was distorted.

I decided to try to measure the stability of the receiver by recording the Canadian time signal station CHU on 7850.00 kHz in USB mode (CHU has no LSB component) over night for over nine hours. The receiver was operated with just its telescopic whip antenna indoors and the audio was recorded with a Tecsun ICR-100 radio recorder / digital audio player. I wrote a Python script to compute the audio spectrum of each one-minute segment of the recorded files using a fast Fourier transform (after removing a DC component). The script then looks for the largest peaks in the spectra centred on a specified frequency and prints out the frequency (to the nearest Hz) and amplitude of the peak. In case the signal has dropped below audibility, a threshold is set and if the detected peak is below the threshold (likely just detecting the random noise background), it is skipped. The specific centre frequency I was looking for was 1000 Hz, the frequency of the tone used to mark each second of the CHU broadcast except when the voice announcement and digital signal are transmitted. In AM mode, the spectrum would consistently show a peak at 1000 Hz but in SSB mode, the peak will vary depending on the receiver frequency setting and the actual frequency of the receiver’s oscillator.

The plot below shows the received CHU one-second tone frequency as a function of time (UTC) from when the receiver was first switched on.


It shows the tone frequency started out at about 1046 Hz slowly dropping in the first half hour to about 1012 Hz and after about an hour stabilized to 1011 Hz ± 1 Hz for the better part of an hour. (This shows that you may have to allow a receiver to “warm up” for perhaps up to an hour before attempting anything close to accurate frequency reading at the order of 10 Hz.) But then, over the course of the next seven hours when the signal was audible, the frequency slowly rose ending up at about 1034 Hz. The variation might be affected by the ambient air temperature (but this should have been nearly constant), air flow around the receiver, and perhaps the charge level of the receiver’s battery. On several occasions, I have turned the receiver on (after being off for many hours) and seen a CHU frequency offset of only 10 or 20 Hz. So, I intend to repeat this experiment sometime to check on the day-to-day frequency stability. This frequency stability measurement technique could also be used with WWV/WWVH by recording the 440, 500, or 600 Hz tones broadcast at different times during the broadcast hour.

Of course, it’s also possible to check the receiver’s frequency offset in real time by switching between AM and SSB modes while adjusting the receiver frequency in 10 Hz steps until the signal sounds the same in both modes. There is also freely available computer software for various operating systems that can display a real-time spectrum of audio passed to it through a microphone or line input. So, a CHU or WWV/WWVH test using such software could also be performed in real time. And alternatively, by tuning say exactly 1 kHz away from the transmitted carrier frequency in SSB mode, the software can be used to measure the audible heterodyne frequency to better than 10 Hz — even 1 Hz. This frequency can then be added or subtracted as appropriate to the dial reading (assumed accurate or with a noted offset) to get the exact transmitted carrier frequency.

By the way, it is possible to calibrate and reset the PL-880 using the procedure documented on the SWLing Post (click here to view).

As a side benefit of the analysis I carried out, we can also look at the quality of the received signal over the recorded interval. In this case, it is a measure of the level of a particular audio frequency rather than the RF signal+noise level we usually get from the receiver S-meter or other signal strength display. This is illustrated in the plot below for the CHU recording. As you can see, reception was mostly quite good between about 02:00 and 04:00 UTC and then became fair but above threshold level until about 05:30 UTC.


The signal was then essentially inaudible up to about 08:00 UTC when with bouts of fading it became audible again for an hour or two with sunrise approaching.

— Richard Langley

Posted in Articles, Guest Posts, News, Radios, Shortwave Radio | Tagged , , , , | 1 Comment

Deadline approaching: Your chance to win a shortwave radio in our Virtual Radio Challenge III

AT_-_Franconia_RidgeWe’ve already received some excellent, creative entries in the Virtual Radio Challenge III: your opportunity to piece together the best radio for thru-hiking the Appalachian Trail.

The CountyComm GP5/SSB

The Prize: A CountyComm GP5/SSB

Rememer: this year, if your entry is picked by our judge (Dennis Blanchard, K1YPP), you will win a new CountyComm GP5/SSB portable radio courtesy of Universal Radio!

To participate in this challenge, simply submit your response in the form on our original post with your suggested set-up, any links, and a brief explanation for your choices.

You’re also welcome to email me directly with your response on or before Saturday, August 8, 2015.

Click here to read the full challenge.

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Guy discovers the $13.99 Babson DS-858 shortwave radio

Babson-ShortwaveSWLing Post contributor, Guy Atkins, writes:

I spotted this new listing on Ebay today, and was wondering if it’s a new model, or perhaps a repackaged Tecsun PL-606? It’s lacking the rotary tuning knob and has a smaller display than the 606 however. It also has two rows of main buttons rather than three:

Curiously, the seller doesn’t even list the brand name in their auction title; it’s only noted in the pictures. However, “Basbon” isn’t exactly a brand of communications receivers with a long, proud tradition :^)

For $13.99 including shipping the the USA it’s hard to go wrong, so I’ve ordered one.

[…]Three features that caught my eye with the little Basbon radio are that it’s DSP based, it has LCD backlighting, and shortwave frequency coverage down to 3200 kHz. There are 20 memories and a sturdy-looking whip antenna that rotates 360 degrees, too.

I can’t wait to get ahold of this and open it up! I wonder which SiLabs chip it uses?

Thanks for the tip, Guy! I’m also very curious about this little portable–indeed, curious enough, I purchased one, too. Guy and I will compare notes and I’ll post an update after I receive the radio. It’s being shipped via ePacket from China, so transit time will be roughly two weeks if not held up in customs.

Frankly, my expectations are very low, but like Guy, it’s a little too tempting at $13.99 shipped!

Click here for a direct link to the Babson DS-858 on eBayclick here to search for the DS-858 should the current item number expire or sell out.

Posted in News, Portable Radio, Radios, Shortwave Radio | Tagged , , , , | 6 Comments

Dr. Phil’s radio articles: portable SDR and pocket DX

RTL-SDR-001SWLing Post reader, Dr. Phil, recently contacted me regarding a collection of articles he’s written about DXing and radio modifications.

His site actually has a number of useful articles that I’ll plan to convert to future posts, with his permission.

Sony ICF-S10MKIII asked Dr. Phil for links to two of his most popular publications. He replied:

My two big recent articles are shown below. One is about “Pocket Radio DX”: using under-$20 radios to DX (started in 2003). Click here to download as a PDF.

The other is about using an $18 NooElec TV-tuner as a MW and shortwave receiver. Click here to download as a PDF.

Brilliant! Thanks so much for sharing these, Dr. Phil!

I actually have a  Sony ICF-S10MK2, which I consider to be a capable and useful little AM/FM receiver for the sub $20 price. I’ve also been very tempted to purchase an RTL-SDR dongle, so I may go ahead and bite the bullet on one of the NooElec SDR dongles.

Posted in Articles, News, Radio Modifications, Radios, Shortwave Radio, Software Defined Radio, Ultralight DX | Tagged , , , , , , | 1 Comment