Review: XHDATA D-219 Short Wave Radio Receiver

As any radio amateur will tell you, the world of radio abounds with exciting possibilities. Probably the simplest pursuit of them all is that of the SWL, or short wave listener, who scours the airwaves in search of interesting stations. SWLs will often have fully-featured setups with high-end general-coverage communications receivers and tuned antenna arrays, but it can start with the cheapest of radios at its bottom end. Such a radio is the subject of this review, the XHDATA D-219 is a miniature portable receiver that costs under ten dollars, yet is currently the talk of the town in SWL circles. This interest is in no small amount due to its being an especially low-price way to get your hands on a shortwave radio using one of the SIlicon Labs integrated software-defind radio receiver chips. We don’t often review a consumer radio here at Hackaday, but with an avid eye for unexpected gems at the cheaper end of the market this one’s worth a second look.

What Do You Get For Your Tenner?

A picture of the radio on my bench
This form factor is very typical for cheap “world band” radios.

I ordered my D-219 from the XHDATA website, spending about £10 including the postage from China. The usual wait ensued before the package landed on my doormat, and inside was the radio in its box with an instruction leaflet. It’s a small unit about 135 mm x 75 mm x 30 mm, and it follows closely the form factor of other similar radios.

On the top is the extensible antenna with an on-off switch and sockets for headphone and 5 V power, on the side are side-on knobs for tuning and volume, while on the front is the speaker and old-style multi-band tuning display.

On the back is a flip-up stand and a hatch for a pair of AA cells. There’s a band switch covering AM, nine different shortwave bands from 4.75 MHz to 22 MHz, the east Asian FM band from 64 MHz to 87 MHz, and the international FM band from 87 MHz to 108 MHz. The tuning indicator is very old-school, a vertical bar that moves across a frequency scale with the tuning knob.

The PCB, showing the surface-mount components
There’s not much to a radio using one of these chips.

Opening it up, and it’s immediately obvious how simple the DSP chip makes a radio like this. Where once you’d have seen a board covered in analogue circuitry taking up most of the space, now aside from the AM ferrite rod antenna there’s a board about a third the size of the case, behind the tuning display. Carefully lifting this up reveals the circuitry, all surface-mount, with a Silicon Labs Si4825 single-chip DSP radio, and a Shaoxing Silicore D2882 audio amplifier being the only integrated circuits.

How Does It Compare To Older Cheap Radios?

A block diagram of the chip, showing its SDR architecture
It seems crazy to give an SDR an analogue interface using an ADC, but you can’t deny it works.

The Silicon Labs single-chip radios are nothing new, having been on the market for over a decade. They come in a wide variety of versions for different applications and control methods, with the Si4825 being one of the lower-end versions. In keeping with its traditional analogue interface it doesn’t have any digital controls, instead it achieves both tuning and band switching by means of voltage. A switched voltage divider selects the band, while a variable resistor serves as the tuning control. Some of the higher-spec chips in the series allow the insertion of DSP code to demodulate for example SSB signals, but this one remains firmly stuck with AM, and FM on the two VHF bands. Inserting some batteries and turning it on, and there were the usual dial-full of FM stations. The real action though lies in the shortwave bands, so that was where I headed next. And immediately I had in my headphones a world of stations, and while the shortwave bands have seen a decline since I first listened to them back in the 1980s, there were still enough for me to quickly identify stations from the far east, north America, the Arabic-speaking world, and from eastern Europe.

Block diagram of a traditional superhetrodyne receiver
Compare this traditional receiver with the SDR block diagram above. Chetvorno, CC0.

When evaluating a small portable shortwave radio like this one it’s important to understand a little about how such radios have traditionally worked. My other older cheap radio with a few shortwave bands is a more conventional model, it has a tuning capacitor that controls both an input tuned circuit and an oscillator. The oscillator is set 455 kHz away from the desired station, and the signal from the antenna is mixed with it to create a so-called intermediate frequency, the difference between the two at 455 kHz. This is then fed into an IF amplifier tuned to 455 kHz from which the audio can be demodulated.

It has two major shortcomings, first that 455 kHz isn’t enough distance from the receive frequency in a cheap shortwave radio, and second that the bandwidth of that 455 kHz amplifier is quite wide. The first leaves the possibility of receiving whatever is on the sum of the oscillator and 455 kHz alongside its difference, while the second sets the slice of spectrum that you are listening wide enough that more than one station can be heard at once. More expensive traditional receivers like my workhorse 1980s Lowe solve this by using a much larger frequency difference than 455 kHz and some expensive filter components to reduce that bandwidth, but you would certainly find neither in a ten dollar radio. The experience of short wave listening on a very cheap radio has thus always been rather dismal. Tuning is difficult, and there is lots of interference and breakthrough from other stations.

How Good is It And Should You Buy It?

A radio based on one of these Silicon Labs chips immediately solves both of the problems from the previous paragraph due to its software-defined architecture: it has no IF offset to worry about, and it replaces the need for those expensive filters by means of signal processing in its software. Thus the effect is much more similar to that of a receiver with one of those expensive IF filters: there’s little or no breakthrough from all those adjacent stations, and tuning becomes much easier. It also seems as though the demodulator is better than its analogue equivalent, returning even weak signals in a much clearer form. How much of this is my imagination and how much DSP tricks I can’t tell you, but the radio certainly delivers.

To sum up the D-219 then, it’s a good little radio that gives good results for a pocket-money price, and I can see why the SWL community are rather excited about it. It will never equal a high-end general coverage receiver with a well-implemented antenna array and even the Silicon Labs SDR chip is not new, but for the price of a couple of pints of beer it’s a no-brainer and a diamond in the rough.

109 thoughts on “Review: XHDATA D-219 Short Wave Radio Receiver

  1. Save your money, and build your own. You will learn more and it is more satisfying.

    I decide recently, not purchase a lot of this read-made ewaste. Especially as there is good chance that it might be made by child or slave labour.

    If you have money spare to buy things like this, and not care about performance etc, then I suggest that you pick a charity, and give them the value of the radio. Moving stuff like this around the world, helps nobody, and just adds to eWaste and general pollution.

    Stephen G7VFY.

    1. Well said. We need to bring back the Heathkit HR10B.. where you learned how a radio was put together and had the pride of building it yourself. I had many fun hours tuning in the world and still have my QSL cards.

    2. So if someone should wish to dip a toe into the waters of short wave listening, they should:

      a) buy a cheap receiver and see if it holds any interest?
      b) spend years and £££ learning electronics, buying tools, kit and components to build a short wave receiver and see if it holds any interest.

      I too am a licensed amateur, albeit with one of those lowly call signs that ‘real’ hams look down on. You will no doubt despise me even more when I tell you that the radio that got me on air was a Baofeng UV-5R, but now I have a proper HF set, with valves in it and everything! I gave the Baofeng to my nephew, who is now doing his Foundation license.

      Cheap gear has its place and it’s not, as you suggest, in the bin.

      1. B) definitely

        It’s like with cheap telescopes. They’re nothing but a disappointment. They ruin the hobby for you just before you have really started.

        Also, shortwave bands with AM are dying out. It’s the amateur radio bands and the national services (weather forecast, Navtex etc) which ate still going strong. Unfortunately, they’re using SSB fir transmission.

        Better borrow a real piece of equipment or get some old, used equipment that used to be professional.

        Imho, Stephen explained it very well. I have nothing to criticize. I thought of it being e-waste, too!

        A simple audion receiver can receive SSB/CW easily, too, I think. Or a Direct Conversion receiver (DC receiver).

        1. So then you go for B, and (assuming your self-built wonder works, of course…) within 5 minutes you decide that listening to a handful of salty old hams going “CQ DX… 5 and 9” isn’t for you… what then? Seriously, referring to receivers like the one in the article as ‘e-waste’ is no more than narrow-minded snobbery, which is – I have to say – an attitude I find all too prevalent amongst older hams.

          My cheap radio was anything but a disappointment, and soon it’ll be helping someone else decide if they want to commit to a new hobby without the need to spend mountains of time and cash just to see if they like it.

          1. A good SSB radio, even if old and used from flea market runs circles around this e-waste. Spending 25, 50 or 100€ is not a waste, it’s a good investment. There are a lots of old Yaesu, Sommerkamp, Radio Shack/Realistic, Heathkit radios still out there and worth to be restored or “refurbished”.

            The radio in the article, what do you want to use it for? Listening to Radio China? Waiting to hear number stations on a random frequency to appear ? Your statement is even worse than mine! Imho. 😝

            With an SSB radio, even the cheapest, you can decode SSTV images in 20m band, on 14,225–14,235 MHz USB, not just “599” and morse telegraphy.
            Just visit WebSDR of university of twente and check it out. It’s more worth than that radio.


        2. My cheap telescope was drectly responsible for me taking an astronomy degree, using the university telescopes, and later in life, buying what I suppose you would deem acceptible.
          Likewise the cheap raido I bought resulted in a life long interest in the airwaves and buying equipment elitests might approve of.

          Cheap equipment does not ruin hobbies or interests. If there is a spark there they fire it up.

          Nice article.
          More of this sort of thing.

          1. Bla bla bla. 🙄 By all due respect, that’s just precocious wisdom.

            A cheap telescope for less thann 500€ is useless. Go ask in an (amateur) astronomy forum if you do not believe me. The optics are simply too bad/insufficient, too badly adjusted to show any star or planet, even in a clear winter’s night. A blurry image of moon is all you can get, at best.

            Radio.. I was there when AM was still life and sound. I’ve built my own crystal radio at age 6.

            But we’re not in the 20th century anymore. Please keep your rose coloured nostalgia for yourself.
            With such cheap AM radios as shown in the article, we’re just scaring away the beginners. They have higher demands than listening to buzzying noise and static. It just hurts their ears.

            Better show them an SDR, an SSTV image received from International Space Station or show them a tube radio. Tube radio, because it looks like alien tech to the youth/the beginners. Also, a radio kit or electronic cobstruction set from the 1960s to 1990s is superior to this e-waste. With 5€ parts you can huod yourself an SSB capable audion/regenerative on a wooden board that’s more fun. Instructions can be found online.

            Or just build a crystal radio for shortwave and make a spider coil by using an old CD case and some insulated wire. Very cheap to build, too.

          2. I agree, a $15 dollar “toy” SW radio gifted to me was incredible fun when I was a kid. That radio was incredibly good, hooked up to the dial stop of a dial phone, there was a new station whenever you moved the radio dial. Sadly, you can’t do that with the best SW radio made today given the dearth of stations broadcasting.

            I also had a horrible $20 dollar telescope with a 2″ mirror gifted to me when I was a kid. That didn’t stop my interest in the hobby, I knew what the limitations were. Astronomers get “inchitis” like boaters get “footitis”.

          3. “Bla bla bla” indicates “due respect”?

            On that cheap telescope for less than 500€ is useless thing, consider Galileo. “His most powerful telescope, with a total length of 980mm and an objective lens diameter of 37mm, magnified objects about 30 times. He used it to view craters on the Moon, the four largest moons of Jupiter, and the phases of Venus.”

            I suggest cheap telescopes, SW radios, or any other cheap hardware associated with a hobby to see if it adequately interests one to justify spending more. This is especially true for kids.

          4. I could not agree with you more. We are really blessed to live in a time when a lot of things that used to be a huge investment just to test the waters are now of enough quality and inexpensive enough for the average person to try. I am amazed at how playable a $100 acoustic guitar is these days. Might not have the nicest tone or be the most playable, but compared to what that same money got when I was a kid it is astounding. A lot of people say get old and fix but.. My wife has a sliver flute and I wanted to try it, she has not used it in 40 years so the pads all need to be replaced as do a couple of springs. Holy good crap, they want near $500 for that. Good luck with that one. I got my ya ya’s out for $80 new. I got the $175 cello too. And I love the thing. Doing recording, OMG there is so much nice gear for not a ton of cash. Ditto with video. Almost anything. The bottom has fallen out, the middle has touched on the top. No doubt the stuff on the top is still nicer, built better, etc, but the difference is not what it used to be.

          5. Excellent point. I started the same on cheap telescopes and old analog radios in the 1990s and today own crazy expensive stuff. Radios like this are wonder boxes for the curious and a stepping stone to stoke the hobby.

      2. I am a ham with a lofty call sign and I am all for the Baofeng radios. The hobby has already been thinned out with the internet and cell phones, and the hobby is getting downright grey. I think it is great that someone can dip their toe into it for $25. If they like it they will want better, and if not, $25 is not a life changing loss. I have a UV-5R and I am continuously amazed at how much value they have packed into it. I hope it prods some of the more old school manufacturers into thinking about that market. If we don’t get more people in our ranks, there are a lot of groups that would love the bandwidth we have. If a $25 radio is what it takes to get more people interested, I am all for it.

        1. Baofeng and their ilk are cheaply and poorly designed, the biggest problem being their unfiltered spurious out of band emissions when transmitting. The company’s flagrant disregard for out of band emissions regulations means their product has not passed required regulatory testing and is not legal for sale in many countries.

          As an engineer and a ham, I’m all for inexpensive radios, but when they are this poorly designed, I refuse to buy them, no matter how popular they may be.

    3. Save your 10 pound, buy something worse for 20 pound or more!

      I fully get the “build your own damn birdhouse” to learn something; but building this yourself will neither get you less e-waste, nor will it lead to the same satisfaction if you’re actually out for good reception.

      Also, I’m highly skeptical an electronics product like this would be made with child labor that would not be found in the materials sourcing – the same area your DIY receiver would probably be more intense in (more copper, discretes instead of integrated circuits leading to lower-quality, higher-volume need for rare earths). I’d greatly appreciate a source for that claim, as it’s a very grave one.

      I’m *really* much for responsibility in supply chains, both in terms of human treatment as well as waste responsibilities, but your solution “DIY” is not better in either aspect.

      1. “whoever buys cheap buys twice”

        RF is a special field. A good receiver needs good analogue part and big coils with a good Q factor. I’m speaking from experience, by the way.

        Same goes for the ADC (A/D converter) of an SDR chip, by the way. Things like resolution, linearity, stability, selectivity and large signal immunity are values/factors to consider.

        Personally, with all due respect, I think this receiver shown *is* e-waste.
        An old ham receiver from flea market or an RTL SDR stick with SW converter frontend is much better! And not much more pricey.

        1. At which magic flea markets do you find ham receivers? I’d gladly visit those ;)
          In the Netherlands, portable radios of any quality at all have disappered from flea markets and thrift shops about 10 years ago. You can get lucky, but the once ubiquitous travel radio has almost completely disappeared from the non-specialist 2nd hand market.

          If the chinese radio is any good, looking down upon it is outright stupid. I have a AM/FM pocket radio with DSP which is absolutely terrible, but unless someone has tried the radio in this article, they should shut up about it being terrible. The author says it’s more sensitive than some other options.

          1. The DSP radio chip used in this is a black box, and there’s nothing cheap that could possibly improve it from the outside. The Silicon Labs radio chips are all minor variations on a single design (variations on how you tune them, for example), so one does not need to hear this particular radio to know it’s limitations. Perhaps what Jenny means is that this is as good as a $10 radio can be these days, and you could do far worse.

          1. Each to his own, to err is human.
            What I’m talking of is experience, not trolling.
            I started with cheap, “simple” radios like this and tried my best to get the most of it. I was both young and poor, when I started the radio hobby. I was in the role of “the victim”, not the snobby rich antagonist with lots of money to waste on a high-end radio station

            Rather, the cobtrary. I learned to walk, to fall and to stand up again. Made my own experience doing so. I even improvised my own tools, because I had no access to the real thing. But if there hadn’t been other helpful souls that provided me accees to *working* radios or electronic constructions sets to experience the potential, the good side of shortwave, then I would have had ended up in despair likely.

            People who advertise bad tech to beginners without lending them a helping hand, are they really doing the right thing? I leave that question open to the readers here.

          2. Addendum: Just checked (found the original boxes in the cellar).. Two of the simplistic radios I had to work with were the Watson TR 4306 and the MFJ 8100K..

            I’m providing this information to prove that I’m not making things up. I really made my journey as a beginner long ago. And my intention simply is to spare other enthusiastic people from disappointment.

            With computer-operated SDRs (RTL SDR, Red Pitaya, SoftRock, soundcard+DC receiver-DREAM software, Adalm Pluto, ) or an old WinRadio receiver it’s way more fun!

            And they allow for all modulation types. They can even hacked and be combined with homebrewed parts.

            What I mean to say, more less: Try to resist the urge to get something “cheap”. Rather, save your money and let it increase a bit, then invest the money in something good that truly makes you happy. That’s more substantial and lasting. Imho.

          3. So by Joshua’s own admission he started with cheap stuff and he has managed to stay all these years and develop all this wisdom. Another way of looking at it is that cheap radios got him hooked for life so he just disproved his own drivel. You sir are what is wrong with this hobby and the world.

          4. “So by Joshua’s own admission he started with cheap stuff and he has managed to stay all these years and develop all this wisdom. Another way of looking at it is that cheap radios got him hooked for life so he just disproved his own drivel. You sir are what is wrong with this hobby and the world.”

            No, I’m saying that I experienced myself how bad those simple receivers can be!

            The FT-101 of my father, -which I was allowed to use for reception from time to time-, showed me how much is going on shortwave.

            My own, simplistic receivers couldn’t do that. The FT-101 opened my mind, so to say. It widened my view.
            It inspired me to NOT to give up on shortwave, but build my own little radios.

            Because of my poor situation, I also got help from friends and some CBers.
            They gave me old communication receivers (with BFO for SSB), used antennas I could repair, et cetera.

            Later on, I got myself an used Eddystone EC-10 communication receiver from the UK.
            It was a wonderful little receiver with a BFO and good AM reception, too.

            Other antique radios like an Yaesu FRG-7000 and Realitstic DX-300 followed.

          5. * by “simple receivers” I meant the commercially sold radios, of course – not DIY or homebrew receivers!
            The regenerative receivers, audions, DC receivers etc. that I’ve built on a kitchen table were better (more versatile) than the cheap commercial radios.

            As Stephen said in his comment, homebrewing is a better alternative to this radio in the article.

          6. Oh he’s the real deal OK; the stereotypical boring old ham. For some reason he reminds me of the Monty Python “Four Yorkshiremen” sketch…

          7. “Oh he’s the real deal OK; the stereotypical boring old ham. For some reason he reminds me of the Monty Python “Four Yorkshiremen” sketch…”

            The funny part is that I’m an optimist and a real tinkerer since childhood. That’s why my way of life was different, maybe. It could well be possible than I’m younger than the people that call me an ” an boring old ham”.

            I think it’s really sad for them that they can’t handle the fact that there are people out there who had certain demands and weren’t satisfied with bad quality.

            Guys, not everyone was satisfied with VHS quality, either. Please learn this. People who loved old movies didn’t necessarily love bad video quality, either: Some people rather went to the cinema and were somewhat immersed by a wonderful film classic that they started to save their money to rather get a VCR for Betamax, Video 2000 or a Laserdisc player. To watch the same film in all its glory rather than bother with VHS. Those people are not snobs, they value film. They pay respect to that film and the artists/actors.

          8. “I think it’s really sad for them that they can’t handle the fact that there are people out there who had certain demands and weren’t satisfied with bad quality.”

            I think it’s utterly sad for you that you can’t comprehend the simple appeal of a small gateway radio to someone trying things out. No-one is suggesting that this radio is as good as an expensive radio, FFS, literally no-one. And yet here you are, now wobbling on about how Laserdisc was better than VHS. Read the room, eh?

        2. I did military comms and am an old fashioned amateur radio op aged 73. A friend of mine who has a Collins R390A receiver tested it against the receiver section of a modern ham tranceiver made in the USA. With the same signal and antenna and switching back and forth it was clear that the 50s era Collins was far superior in every category. The signal on the Collins was full quieting with great audio while on the “state of the art tranceiver the signal was hissy and thin. He was surprised but I wasn’t.

      2. I’m not sure why some Americans keep on parroting the well worn Chinese child labour nonsense. It’s complete fiction. It’s like the story that Uyghers in North West China are slaves to the cotton picking industry and sweat profusely building Solar panels by hand. Those stories are simply just crap. Clearly the people generating these fictional narratives haven’t been to China…haven’t been inside a chinese PV panel plant, and haven’t clapped their eyes on the world’s biggest mechanical cotton havesters that roam the Chinese cotton fields. The truth of the matter is, China in 2021 had more than 53% of all the robotics hardware in the world, while Germany and the USA had %’s around 9 -13%. It’s also ironical that the US makes a song and dance about the falling birth rates in China and align that with extrapolated falls in productivity…but the reality is/will be quite the opposite simply because of the huge head-start China has with applied robotics. The other badly misunderstood narrative is what really is China like. It’s helpful to understand that only about 10% of Chinese people are registered as Communists. The rest are just ordinary folk, ordinary families, working hard to make enough money to lift and provide their small families with the best possible education that they can arrange.

        1. “It’s helpful to understand that only about 10% of Chinese people are registered as Communists.”

          It’s not the average people of a nation that are a problem. AS ALWAYS, it’s their governments. And to anyone thinks that a CCP world hegemony is preferable to, for all of its faults, a Western one, you really need to read a few books.

      1. When I was like 7, I missed SSB reception so badly. To listen to RTTY signals, to the ham bands, decode weather fax etc. I’ve even got a cheap, but overpriced MFJ receiver which turned out to be an unstable regenerative type with hand capacity.
        Without my father’s old Yaesu FT-101 to the rescue, I would have been given up on shortwave listening, I think. Those cheap AM radios of the late 20th century are nothing good to people with a least a little bit of self-esteem and a minimum amount of demands.

        1. Lucky there was an FT-101 lying around for you to use! If only all beginners had access to such an expensive, specialist piece of equipment.

          “…cheap AM radios of the late 20th century are nothing good to people with a least a little bit of self-esteem…”

          The arrogance is strong in this one.

          1. The FT-101(FT-277) was already a museum’s piece at the time. It was very popular and mass produced, like the original Gameboy, the DMG-01.

            Since the FT-101 had tube finals, but a solid-state receiver, a “broken” 101 was still useful to SWLs:
            As time went on and when the final tubes “burnt out” and became difficult to replace, radio amateurs sold their FT-101 for little money.

            “The arrogance is strong in this one.”

            I’d say that the real fools are those who dare to judge about those others they don’t know about.

        2. My first HF radio was a FT-101E. 12BY7 driver & 2-6JG6B in the PA if I remember right. Yes solid state receiver. Great radio I’m it’s day. Now days they have way more many features that assist with interference & adjacent channel rejection.

    4. I’m surprised by this attitude. The whole point of this radio is it’s quite a good little radio, and not e-waste. I could make one and I have made many radios, but if you want a little radio, this is a good one.

      As to child labour, having taken it apart i can tell you the most labour that went into it was a pick-and-place robot. It’s an *extremely* simple device thanks to the SDR chip.

      Jenny G7CKF

          1. Weird attitude. And a one that does not make curious people feel welcome to the radio hobby.

            I’ve had more fun with my 8€ radio from the local cheapo-mart, than I’ve had with my HF-station. And I bet that radio is even worse than the one in this article. But I’ve had fun. I also had lots of fun listening to radio with a cheap double cassette deck in my youth.

            People can have fun even if it means doing it differently from you, kid.

      1. Jenny, based on your review I picked up a couple of these. Like you, I immediately disassembled the radio. I re-routed the antenna wire, which was too long and poorly dressed. I added an SMA Jack for an External Antenna using RG-174 and attached the Ground to the PCB’s ground plane. Next I cut the trace from pin 1 of the Si4825 to the LNA_EN. I placed a switch across the trace, which turns on the LNA. The LNA is effective when using the telescoping rod antenna, but can overload when using an External Antenna. There’s a ton of info on the Si4825 and this little guy is very sensitive and is a great platform for modifications. Cost me less than $9(USD) delivered, which is a fraction of the cost of a Si4825 Development Board. I’ve been building radios since age 9, and at 71 I can say that none of my homebrew xtal sets, regens, or direct conversation receivers worked as well as this XHDATA D219.

    5. Went out and draged 3 home. Then kited them out. Adding a clip on antenna. A box for batteries. / Head phones. Then finished the works. With a canvas bag. And note book. later found a b.f.o., and a down converter for 6 meters. I’m hog HEAVEN de kv4li

    6. A lot of people are missing the point of this thing. Its not a $1000 dollar receiver, its something you can put in your pocket and take with you round the world.
      Furthermore I have one in front of me, and it works surprisingly well.
      Think of of it as an $10 eval board for the Silicon Laboratories SI4825-A10 if you will. The PCB suggests it sticks fairly closely to the reference circuit in datasheet.
      As to it being instant ewaste, and assembled by child labour in China. Try to stick to provable facts please. If you don’t have experience of the device, and you know nothing about the manufacturer, then you are simply indulging your prejudices, an all to common and depressing aspect of the modern post truth, facts don’t matter, anti-scientific world that we are slowly sinking in to.
      (and cue the trolls in three.. two… one…).

    7. I am old army Sargent living on a paupers wages. Thou I see some labour in camps. I like to think that some one gets feed. I still work the truck stops, and reach in to the trash bins to find busted radios. And a few get recycled and given away. so once in a while I find or purchase the tener’s quite the experience. a real learning tool. Hi hi. I have glaucoma. And I am willing to see what the other half has over my advanced age. Of 72 Stephen Williams Sgt retired. God has more in store and will get us by trust hasus.

  2. I’ve found similar radios on open air market, but if now they’re digital radios, I think it’s better to spend a bit more and have one that has a digital frequency readout. I suppose that the sensitivity and the audio quality is going to be the same, but with the added advantage of an easier tuning and scanning.

    1. Oh yes, tell me more about this. I was previously considering the Malachite radio, but I was put off by all the Chinese fakes, and the weird way the creator released the firmware, then Russia exploded…

  3. It baffles me that shortwave radios without SSB are still being made, at all. All it needs is a little beat frequency oscillator (BFO) to make it happen. The concept is so simple that it doesn’t even have to be physically attached to the existing circuit. Why, just why are worthless AM-only radio still being made if SSB reception is so simple and cheap to add?! 😔

    1. The old beat-frequency oscillators took advantage of the fact that once the signal was in the intermediate frequency section, its frequency was constant, so the BFO only had to produce a sine wave close to the IF frequency. With DSP-based radios, that don’t use an intermediate frequency, or whose intermediate frequencies are highly variable, this option is not available.

      1. Thank you for the information, makes sense. 🙂👍

        I just wonder why there exist DSP ICs in the same DSP line with their SSB support being removed, however. I suppose that saves them about 5 cents of manufacturing costs? 🤷‍♂️ Why wasting manufacturing resources/capacities in the factory to make these inferior chips?

        If so, then why don’t manufacturers simply ignore them and limit themselves to the good DSPs?

        The customer in question doesn’t really notice if the radio costs 1 or 2 Euro or USD more. The final price the customer has to pay is way overpriced, anyway. He/she/they is being robbed, either way, anyway. Due to maximum profits. I assume manufacturing cost are up to around 3-5 Euro/USD, price of the radio 20 Euro/USD..

      2. That means you can’t add a BFO, unlike portable radios of days gone by.

        But, it’s not inherent to SDR that you can’t receive SSB. Demodulation is done digitally, so SSB is as doable as AM or synchronous detection.

        Something in the design keeps SSB off. Maybe intended for a specific market. These ICs are SDR, but they tend to be limited. So they aren’t completely programmable.

        And as a side note, many low end receivers used by beginners were awful for SSB. My Hallicrafters S-120A, bought new in 1971, couldn’t receive SSB, the BFO way too weak. But that fact taught me things.

  4. I bought two of this radio and a week later they stopped working. The started making a winning noise and stopped receiving radio signals…..two and both do not work any longer. I did get a credit for the two radios. I have several XHDATA radios and all work fine but this model has some sort of defect.

  5. I have a techsun radio with SSB, sadly it came (from an eBayseller) with a broken off telescopic antenna, it was broken from the circuitbord, so no means to repair it, I was tempted to solder a wire to the circuitboard, but decided against it.
    Shortwawe works great on it, but I was dissapointed that it mutes the signal when tuning, wich makes it hard to find signals.
    Oh, it also has airband, but of course on the telescopic whip so I only tested it with a crocodile clip on the board as an antenna.
    A great radio that I would use all the time if not for the briken antenna

        1. A spread apart coil or a hula hoop coil of that size will really pick up much and cut out a lot of noise. Put a smaller 1 turn loop in the center and run with coax into a car radio’s antenna jack. Best of AM of all. The car radio can be a freebie. I wished I’d built one when young and getting WLS down state and with a local 30kHz away. Bled bad with the first radio, only an all American 4 not 5. Once I got a junkyard car radio an A A 6 much better but still some noise.

      1. I have found that a house (ESPECIALLY A GEEK’S HOUSE) is an RF nightmare these days. Also, plasma TV’s essentially wipe out all AM broadcasting from 200 kHz to 20 mHz. I have no idea how the FCC permitted these to be sold.

        You want good shortwave, you either need an outdoor antenna or a steerable/tunable indoor antenna.

        1. Yes, this. I have more than a few SW radios of different make and vintages, and the interference you get from a simple longwire antenna is really discouraging. I have identified some of the noisemakers, but there’s so many… but there’s so little now on SW that’s worth listening to… -sigh-

  6. It’s less than a tenner, posted. It is an *excellent* receiver for the price, less noise than I was expecting, more signals on the in-built antenna than I expected AND it covers 4m FM receive. What is not to like? I love mine. I’m going to buy a few more as I reckon they’ll make great presents for friends and keep a spare. Ideal for holidays!

    1. I didn’t mention the 4m bit because I didn’t want to make American readers jealous. :)

      On a serious note, has anyone tried a radio like this when there’s some 4m activity? I would be interested to know how well its WFM demodulator deals with NFM.

        1. Considering how few inexpensive radios can demodulate SSB, I think it’s pretty unlikely that the chip manufacturers would want to add these features, especially since they can be implemented at the demodulated audio level. Even the inclusion of shortwave bands is pretty much there only because the incremental cost at the chip level is very close to zero.

  7. Thank you for another enlightening article.

    I was rather bemused by the “build your own’ meme. Rather clearly the comments were made by people who don’t design radios, as anyone who does will recognize the virtues of these offerings.

    The real question is, “Can you hack them?”

    1. Well, in the case of the SiLabs chips, you really CAN build your own, and expect it to work. These are truly systems on a chip, and don’t depend on any RF magic outside the chip.

      As for hacking, sure you can hack them – most of these are I2C controlled chips, so slap an Arduino Nano, and you can hack to your heart’s content. I bought a manufactured version of an open-source radio called an ATS-20, which is available as a populated PCB, or various kits of parts. This is a SiLabs radio on a PCB with a Nano, along with an audio amplifier to feed headphones or a speaker. Mine included an OLED display and Li-Po battery with charger, and the case is a pretty heavy duty aluminum extrusion, with PCB front and rear panels. The firmware was easily available, and although this took a bit of digging to find the exact version that applied to this configuration, I was able to build the code successfully and then hack it in a number of ways. There is also something called an ATS-25, which is pretty much the same radio but with a more capable microcontroller, an ESP-32 IIRC, and a full color LCD display. I didn’t really see the justification for that upgrade, and have been happy with the ATS-20. The version I bought, with a case, speaker, antenna, and charging/programming cable came to $60, but there are kit versions as low as $20 if you’re serious about your hacking. So not QUITE $10, but worth the difference for sure. Incidentally, you can tune continuously from around 150 kHz to something close to 30 MHz in AM or SSB, as well as both the European and American FM bands, and you can also set it up to do this in as many bands as you like, just by modifying the band table in the source code. Oh, almost forgot: the ATS-20 includes a pretty hefty hack, as it can also demodulate SSB on the AM bands, using a DSP blob developed by some Russian guy, if the lore is to be believed. I wasn’t able to find any documentation about the DSP core itself, so I won’t be further hacking that part of it myself, but good luck finding that on any other cheap radio!

      1. “…so I won’t be further hacking that part of it…”

        So then I went to Google again, this time not looking for an app note for the Si47xx chips, but for DSP in general from Silicon Labs. What I found was a document about how to do DSP with an 8051 family microcontroller (, from 2008. This specifically targets their own C8051F12x and C8051F36x chips, which the document says are well-suited to DSP because they include a 16×16 multiply-accumulate instruction and on-chip ADC and DAC. Which led me to wonder if they used the same 8051 core in their radio chips to do the DSP. Since I’ve got the binary patch data to do SSB and narrow-band FM demodulation with these chips, I think what I need to do is try disassembling the patch file. Unfortunately, I don’t know what the format of the patch files is. It’s just a list of hex bytes, but I don’t know how this translates to “put this instruction at that address”. But maybe it’s just a variation on the Intel binary format, so I guess I need to give that a try.

        Incidentally, the lore about the origin of the SSB and NBFM patch being a Russian hacker wasn’t quite right: HE (Vadim Afonkin) got it from Silicon Labs; there’s even a Silicon Labs copyright notice on the patch files. Unfortunately, Silicon Labs’ automotive an infrastructure division, which makes their AM/FM radio chips, got sold to Skyworks a couple years ago, and now neither Skyworks nor SL has the app notes for these (which is where I would expect to find this patch and its source code) on their websites. This is what happens when companies buy companies – something always gets lost in the transfer.

        1. Hm. Worse than that. AN332, page 236: “Patches are tagged with a unique identification to allow them to be tracked and are encrypted requiring the customer to use a tag when downloading to allow the Si47xx to decrypt the patch.”

          1. Yes, I know that. I have it in my radio. But it’s just a useless blob. How am I supposed to make improvements to a device that is hidden from me?

    2. “I was rather bemused by the “build your own’ meme. Rather clearly the comments were made by people who don’t design radios, as anyone who does will recognize the virtues of these offerings.”

      On the other hand, someone could argue:
      The people who design those radios clearly don’t do use them, as anyone who would will recognize their shortcomings. 😜

  8. “It seems crazy to give an SDR an analogue interface using an ADC, but you can’t deny it works.”

    Not the least bit crazy. Users expect to tune a radio with a continuous control, and the cheapest controls available are potentiometers. This is what allows a £10 radio to be built.

  9. @Jenny List said: “Carefully lifting this up reveals the circuitry, all surface-mount, with a Silicon Labs Si4825 single-chip DSP radio…”

    Hi Jenny, great article. I did not know about the XHDATA D-239 <$10 DSP AM/FM/SW pocket radio. I'm nit-picking again… Silicon Laboratories no longer manufactures these Si4XXX DSP radio chips. The whole line was sold to Skyworks Solutions back in July 2021.[1][2]

    1. Silicon Labs Completes Divestiture of Infrastructure & Automotive Business

    AUSTIN, Texas, July 26, 2021 /PRNewswire/ — Silicon Labs (NASDAQ: SLAB) announced today the completion of the divestiture of its Infrastructure & Automotive business to Skyworks Solutions (NASDAQ: SWKS) for $2.75 billion in an all-cash asset transaction.

    2. We have officially divested our Infrastructure and Automotive business, (comprised of Timing, Power, Isolation, Broadcast, and Automotive products) to Skyworks Solutions.

  10. @Jenny List said: “Some of the higher-spec chips in the series allow the insertion of DSP code to demodulate for example SSB signals…”

    I’m not sure myself if there needs to be some DSP code insertion into the Skyworks DSP radio chips or if there just needs some option bits flipped. But in-general…

    One fairly simple way to demodulate SSB using DSP is to down-convert in quadrature (IQ) then apply the IQ signals via ADCs to the Hilbert Transform in DSP.[1][2] Some hackers have been able to get into the DSP section of these Silicon Labs (SiLabs, now Skyworks Solutions), DSP receiver chips (usually Si47XX) and make changes that enable SSB (USB/LSB) demodulation.[3] There is even a forum on this topic.[4] Finally for as low as $55 USD you can buy a pre-built multi-mode AM/FM/SW receiver with SSB.[5] However, from what I can see, for more serious work I would recommend adding some bandpass filtering to the front end of the $55 receiver.

    1. SSB Demodulation

    2. Hilbert Transform

    3. PU2CLR / SI4735 (Ricardo Lima Caratti)

    4. SI47XX for hobbyists

    5. ANYSECU SI4732 Shortwave AM FM Radio ATS-20 AIR Band DSP Full Band (MW & SW) SSB (LSB & USB) Scanner Portable Radio $55.99 (I have never tried this product).

    NOTE: I have no affiliation with any product mentioned in this comment – O.P.

  11. Instead of having another internet fist fight can we get a solid recommendation for which old radios are good and should be bought? I discovered my little emergency radio and realized I would like to have something like that for camping and fishing, and when I go trail exploring on a motorcycle. There have to be some top of the line Sony or something radios on Ebay that have great features and super reception.

  12. If you want to play radio, these chips do look like fun. FYI silicon labs has divested them the radio chips now come from and I can find zero info on the Shaoxing Silicore D2882 amp IC, I am assuming had could not either given no hyperlink to the datasheet.

    It would be cool if someone made a breakout board for these chips that had like the width of a 40 pin dip and had the crystal and caps on it as well as some pads big enough to hold the small amount of RF interfacing, but brought the rest of the pins out for breadboarding. That would let you keep all the RF wiring nice and short and not have to worry about all the parasitics of bringing the crystal and rf stuff down to the breadboard. It looks like everything else would be happy. That would make a nice hacking platform for the chips I think.

    1. +1. Not that it’s that hard to use SOICs such as these for Manhattan-style or just plain deadbugging, but it’s a good idea to put the oscillator components close to the chip and isolated from everything else. Also, don’t worry about whatever Chinese audio amp chip the radio reviewed here uses, there are dozens of other ways do to an audio amp just as well (I’m sure their choice was almost exclusively based on price), and you can choose between headphone or speaker, mono or stereo (for the FM band). And if you use a class D amp chip, the power consumption will be quite good, even when driving a speaker.

      1. I was not concerned about the amp, just curious as to what it was. I like to see new chips. As far as the radio chip, no it does not look like it would be hard to deal with but it is not breadboard friendly, and the parts I mentioned would not be good for breadboarding, so kill two birds with one proverbial stone and make a little board that transforms the pins that make sense to breadboard with and put some pads for the stuff you want to keep near the chip. It looks like you could spin up a DIY version of one of these radios in an afternoon and it would probably work.

    2. I assume the Shaoxing Silicore D2882 IC to be a clone of the TDA2822M dual low voltage power amplifier IC. It is no longer available in DIP package except from Chinese clone.

  13. Hello. I recently purchase the XHDATA D219 and am impressed for the price even in Australia.
    I was a licensed Ham radio operator in the 1960s -1980s so I grew up with mostly analog stuff.
    I’ve recently taken up SWL and have various receivers inc. a Tecsun S2000 and a good old refurbished Realistic DX160.
    Jenny, I enjoyed your review, especially the info re the Silicon Chip signal processor. My S2000 is a dual conversion PLL receiver. The confusion lies in this obviously being digitally tuned with up and down conversion memories display etc. Am I right in saying this is a Digital PLL receiver but NOT a DSP receiver.
    I.e the signal itself is not digitized but treated in the mixing, IF stages etc as an analog signal.
    I guess there can be confusion between digitally tuned and controlled receivers and DSP chip receivers.
    Friends often ask me if my S2000 is a ‘Digital’ receiver and think of it as a D219 on steroids or something.
    I would appreciate your wisdom on this

    1. You are correct, sir. A digitally-tuned radio is not (necessarily) a DSP (Digital Signal Processing) radio. The distinction is that in a PLL circuit, the local oscillator is digitally divided by one number, while the reference oscillator (generally a crystal oscillator) is divided by another, and the two are compared in a closed loop that controls the frequency of the local oscillator. This means that the oscillator can be tuned to any fraction (including fractions > 1) of the reference frequency, just by selecting the numbers that the reference and LO are being divided by. This is what makes them “digitally tuned”. But as you say, the actual received signal is usually analog throughout.

      The big difference with DSP-based radios (including SDR, “Software-Defined” Radios), is that early in the signal path, the signal is converted from analog to digital, replacing circuit modules that use physically large and relatively expensive analog components such as inductors, transformers, and crystals, with mathematical constructs in a computer optimized for handling the particular math involved.

      For the most part, the advantage of DSP is cost, but there are additional benefits such as high stability and flat-topped, sharp-edged filters, so you can often get great performance at very low cost. But there are also limitations, mainly introduced by the analog-to-digital converter used, and this is the most expensive part of a DSP radio. The ADC is selected to get the best performance for a given cost, with that performance being dominated by the effective number of bits, which drives the dynamic range of the receiver, and the sampling speed, which determines the maximum bandwidth it can process in real time. Also, because of cost constraints, many DSP radios have little filtering before the ADC, so in the presence of one or more strong signals at the antenna, the signal has to be attenuated to avoid distortion, thus reducing its sensitivity.

      Most DSP radios are hybrids, with the local oscillator and first mixer of a superheterodyne (with the local oscillator either a PLL-tuned or a directly synthesized oscillator) and a mixer, creating an intermediate frequency signal that is then fed into the ADC, an thence to the DSP. For most applications, you need two phases of the IF signal to properly demodulate it, so there are actually two mixers, one mixing the incoming signal with the direct output of the LO, and the other mixing a 90° shifted copy of the LO, each of these either feeding a separate ADC, or sometimes being multiplexed into a single ADC. The Silicon Labs chips like the one used in the radio described in the article all use the same single-conversion, dual ADC architecture.

  14. It seems you may be able to hack this little radio to give wide and narrow band operation.
    The SiLibs reference design is available online.

    I’ll leave it as an exercise for the reader to figure out how to perform the modification.
    It should also be fairly trivial to add an external antenna jack, and may be possible to add additional bands.

    C’mon folks, this is Hackaday. Hack the thing.

  15. The D-219 is incredible for the price; you can spend that much on lunch at a fast food restaurant, but a radio like this only goes so far.

    It’s difficult to identify a station because there is no precision in the tuning, and there is also some variation between units with the dial pointer being more or less accurate depending on which one you get. It has no dial light; it can’t be powered with a USB cable, no stereo FM, SW coverage is limited, and the bandwidth is overly broad.

    One might argue that this is a good “starter radio” because of the low price, and I get that, but there are other radios with a digital display for not that much more money.

  16. All these hams snobbing about their equipment, I cannot stand their high horse attitude. When I was a kid I had to pay a lot of money for a simple portable MW radio that turned out to be way more rubbish than these cheap dsp radios. Yes, dsp leaves a lot to be desired, but come on, you are not the standard, but for the perfect example of grumpy old hams. And because of all the snobbery I will buy one of these. Fun for a tenner is sometimes more important than the amount of money you paid to show off. Fun lies in simple things. 73’s from Holland.

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