Category Archives: Shortwave Radio Reviews

Software Defined Radio Primer Part 1: Introduction to SDRs and SDR applications

The new ELAD FDM-S3.

The following article originally appeared in the June 2018 issue of The Spectrum Monitor magazine:

SDR Primer Part 1: Introduction to SDRs and SDR applications

I author a radio blog known as the SWLing Post; as a result, I receive radio-related queries from my readers on a daily basis. Among the most common questions are these:

“So, what is an SDR, exactly? Are these better than regular radios?”

and/or,

“I think I’d like to buy an SDR. Which one do you recommend?”

Great questions, both! But, before I address them, I must let the reader know that they are also “loaded” questions: simple enough to ask, but quite nuanced when it comes to the answers.

No worries, though; the following three-part primer sets out to address these questions (and many more) as thoroughly as possible. This first part of the primer will focus on the basic components of an SDR system. In part two, next month, we’ll look at affordable SDRs: those costing less than $200 US. In part three, we’ll take a look at pricier models and even include a few transceivers that are based on embedded SDRs.

But before we begin, let’s start with the most basic question: What is a Software Defined Radio (SDR), exactly?

Not your grandpa’s radio

Here’s how Wikipedia defines SDR:

“Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.”

Whereas your grandpa’s radio was all hardware––in the form of filters, mixers, amplifiers, and the like––SDRs are a mix of hardware and software. With the exception of tabletop transceivers and receivers with embedded software and systems (which we’ll discuss in part three of our investigation), SDRs typically take on a “black box” appearance: in other words, the radio looks like a simple piece of hardware with a minimum of an antenna port, a data port and many times there’s also some sort of LED or light to let you know when the unit is in operation. On some models of SDRs, there is a separate power port, additional antenna connections, power switch, and possibly some other features; however, “black box” SDRs often look like a nondescript piece of portable computer hardware––something like an external portable hard drive.

Why would you want an SDR?

Many of us have made it through life thus far without an SDR…so, why in the world should we want the use of one? Below, I’ll list some of the most appealing reasons:

Bang-for-buck

The Airspy HF+ (top) and FDM-S2 (bottom). Photo by Guy Atkins.

By and large, SDRs are quite a value when compared to legacy all-hardware radios. For example, I wouldn’t hesitate to pit my SDRs––such as the $500 Elad FDM-S2 or $900 WinRadio Excalibur––against legacy receivers that cost two to three times their price. Indeed, my $200 AirSpy HF+ SDR will give many DX-grade ham radio general coverage receivers a real run for their money. They’re that good.

Spectrum display

SDR applications have a spectrum display which gives you a real-time view of a broad swath of the radio dial. Whereas you can tune to and listen to one frequency at a time with legacy receivers, SDRs allow you to view, say, the entire 31 meter band. With the spectrum display, you can see when signals come on or go off the air without actually being tuned in to them. You can tell what signal might be causing interference because you can see the outline of its carrier. Spectrum displays are truly a window––a visual representation––of what’s on the radio. Using legacy receivers now often makes me feel like I’m cruising the bands with blinders on. After becoming accustomed to having a spectrum display, there’s simply no way I’d want to be without at least one SDR in my shack.

Powerful tools

I like how clean the user interface is for this SDR application (SDRuno) window that controls the SDR’s frequency, mode, filters and notch.

SDRs usually afford access to a dizzying array of customizable filters, gain controls, noise blankers, digital signal processing (DSP), audio controls, and more. Being able to customize the SDR’s performance and listening experience is simply unsurpassed. In fact, it’s almost a curse for SDR reviewers like me––comparing two SDRs is problematic because each can be altered so much that identifying the best performance characteristics of one or the other becomes a real challenge. In other words, comparing SDRs is almost like comparing apples to oranges: even using a different application can enhance and thus alter the performance characteristics of an SDR.

Multiple virtual receivers

SDR Console makes managing multiple virtual receivers a breeze.

Whereas most legacy tabletop receivers allow you to switch between two VFOs (VFO A and B) some modern SDR applications allow for multiple independent virtual receivers––in essence, multiple sub-receivers. On my WinRadio Excalibur, for example, I can run three fully-functional and independent virtual receivers within a 2 MHz span. On receiver 1, I might be recording a shortwave broadcaster on 7490 kHz. On receiver 2, I might be recording a different broadcaster on 6100 kHz, and following a 40 meter ham radio net on 7200 kHz in the lower sideband.

Recording tools

SDR applications, more often than not, have functionality for making audio recordings of what you receive. Some, like the WinRadio Excalibur and SDR Console, actually allow for multiple simultaneous recordings on all of their virtual receivers.

SDR Console recording dialog box

Most SDR applications also allow you to make spectrum recordings, that is, to record not just one individual broadcast from one radio station at a time, but to record an entire broadcast band, all at once. Each recording can easily contain dozens of stations broadcasting simultaneously. Later, you open the recording and play it back through the SDR application. Recordings can be tuned and listened to as if they were live. Indeed, to the SDR application, there is no difference in using an antenna or using a recorded spectrum file; the tuning experience to the listener is also identical.

So imagine that propagation is stellar one evening, or there’s a global pirate radio event just when you’re going to be away from home: simply trigger a spectrum recording and do a little radio time travel tuning later. It’s that easy.

Constant upgrades

Both SDR applications and SDR firmware are upgradable from most manufacturers. In fact, I’ve found that the most affordable SDRs tend to have the most frequent upgrades and updates. Updates can have a positive impact on an SDR’s performance, can add new features, such as the ability to expand the frequency range or more filters or embed time stamps in the spectrum waterfall. It could be pretty much anything and that’s what’s so brilliant. As a user you can make requests; your SDR’s developers might, if they like the idea, be able to implement it.

So, what’s not to love?

Looking at all of these advantages of SDRs over legacy radios, it sounds like SDRs should truly suit everyone. But the reality is, they don’t. For some radio enthusiasts, SDRs do have some unfortunate disadvantages:

First, if you’re primarily a Mac OS or Linux user, and/or prefer one of these platforms, you’ll find you have much less selection in terms of SDRs and applications. While there are a few good applications for each, there are many more SDR applications for PCs operating Windows. Until I moved into the world of SDRs, in fact, I was a Mac OS user outside of work. At the time, there were only one or two SDR applications that ran on the Mac OS––and neither was particularly good. I considered purchasing a copy of Windows for my MacBook, but decided to invest in a tower PC, instead.

Second, one of the great things about legacy radios is that with just a radio, a power source, and an antenna, you’re good to go; travel, field operations, and DXpeditions are quite simple and straightforward. SDRs, on the other hand, require a computer of some sort; when traveling, this is typically a laptop. I’ve spent several summers in an off-grid cabin in Prince Edward Island, Canada. My spot is superb for catching DX, and there’s no RF interference, so I love making spectrum recordings I can listen to later. Problem is, powering so many devices while off-grid is an art. Normally, my laptop can run off of battery power for hours, but when the laptop also provides power to an SDR and portable hard drive, it drains the battery two to three times faster.

The ELAD FDM-DUOr (receiver).

With this said, keep in mind that there are fully functional tabletop radios (like the Elad FDM-DUO and FDM-DUOr) that are actually SDRs, providing an easy way to bypass this concern.

Finally, there are simply some people who do not care to mix PCs and radio. I’ve a friend who’s a programmer, and when he comes home to play radio and relax, the last thing he wants to do is turn on a computer. I get it––as a former programmer, I used to feel that way myself. But the world of SDRs lured me in…and now I’m a convert.

Scope of this primer series

The world of SDRs is the fastest growing, most dynamic aspect of the radio world. Because of this, I simply can’t include all SDRs currently on the market in this primer. Let’s face it: there are just too many, and it is beyond the scope of this article to try to cover them all. Instead, I’ve curated my list, by no means comprehensive, to include a selection of the most popular and widely-used models.

I’ll be focusing on SDR receivers unless otherwise noted. In Part Three, I’ll call out some popular SDR transceivers. Additionally, I’ll bring my attention to bear on the “black box” variety of SDRs.

This primer is long overdue on my part, so I’ll provide answers to the most frequent questions I receive. But though this primer is in three parts, it barely scratches the surface of the vast world of SDRs.

Thus far we’ve defined an SDR and discussed its advantages and disadvantages.

Now, let’s take a closer look at what you’ll need to build a station around an SDR.

Assembling an SDR station

Guy Atkins’ laptop running HDSDR software in his SUV; the receiver is an Elad FDM-S2. (Photo: Guy Atkins)

In truth, most of you reading this primer will already have everything you need to build a listening post around an SDR. Understanding the components of the system in advance, however, will put you in a better position to get on the air quickly with an SDR that suits your needs best. Let’s discuss this component by component.

A computer

By virtue of reading this primer now being displayed on your screen, unless you’ve printed it out, I’m guessing you have access to a computer of some sort.

SDRs are really quite flexible in terms of computer requirements. SDRs are compatible with:

A desktop PC running the Windows operating system
A laptop PC running the Windows operating system
A desktop Apple computer running MacOS and/or Windows
A laptop Apple computer running MacOS and/or Windows
A tablet or smartphone computer running Android or Windows
A Raspberry Pi/Beaglebone (or similar budget computer) running a Linux distribution

If SDRs are compatible with so many computer operating systems and configurations, then why would you worry about which ones to choose?

As I mentioned earlier most, but not all, of the SDR applications on the market are only compatible with the Windows operating system. If you want the most out-of-the-box, plug-and-play SDR options, then you should plan to use a Windows PC. If you’re a MacOS user, fear not. Modern Apple computers can support Windows—you simply purchase a copy of Windows and set your system to boot as a Windows machine (assuming you have the storage space for a dual boot).

Secondly, processing speed is certainly a factor: the faster, the better. While you can use an Android/Windows tablet or a Raspberry Pi to run an SDR, they often don’t have features like multiple virtual receivers, wideband spectrum recording capabilities, and large fluid waterfall displays due to the simple lack of processing power. My guess is that by 2023, however, tablets and budget computers will have ample processing power to handle most, if not all, SDR functions.

Finally, if you plan to make spectrum recordings, especially wideband ones (2 MHz, plus), you need both a snappy processor and a high-capacity hard drive with a decent write speed. This is the reason I now have a desktop PC at home for spectrum recordings: I can use a very affordable SATA drive as a storage device, and the write speed is always more than adequate. My OS and SDR applications run on an SSD (solid state drive) which is very fast. All of my recordings are saved to internal and external 4TB+ hard drives. Happily, I’ve never had a hiccup with this system.

An SDR application

SDRuno has an attractive user interface comprised of multiple adjustable windows.

Wait a minute…am I suggesting you choose an SDR application before you choose an SDR? Why, yes, I am! You cannot use an SDR without an SDR application, but, with only a few exceptions, you certainly can use an SDR application without an SDR attached.

Unlike a legacy hardware radio, you can essentially test drive an SDR by downloading an application (almost always free) and then downloading a test spectrum file. Most SDR manufacturers will have all of this on their download page. Simply install the application, open the spectrum file, et voila! You’re now test driving the SDR. Your experience will be identical to the person who originally made the spectrum recording.

The WinRadio Excalibur application also includes a waterfall display which represents the entire HF band (selectable 30 MHz or 50 MHz in width)

I always suggest test driving an application prior to purchasing an SDR.

While all SDR applications have their own unique layout and menu structure, almost all have the same components, as follows:

a spectrum display, which gives you real-time information about all of the signals within the SDR’s frequency range;
a waterfall display, which is a graphical representation of the signals amplitude or strength across the SDR’s frequency range displayed over time;
filter controls, which help you adjust both audio and signal widths;
mode selections, which allow you to change between modes such as AM, SSB, FM, and digital;
a signal meter, which is typically calibrated and resembles a traditional receiver’s “S” meter;
a frequency display for the active frequency;
VFOs/virtual receivers, which may have real estate allocated on the display;
a clock, which displays the time, possibly as both UTC and local time (note that many SDR apps also embed time code in waterfall display);
memories, where you can store a near-infinite number of frequencies (and some SDR applications allow you to import full-frequency databases); as well as
other controls, such as squelch, gain, noise blanker, DSP, notch,etc.

After you’ve become comfortable with one SDR application, moving to another can be a little disorienting at first, but the learning curve is fairly short simply because most have the same components.

Types of SDR applications

SDR applications usually fit one of three categories: proprietary app, free third-party apps, paid third-party apps, and web browser based apps. (Assume each application runs on Windows unless otherwise noted.) Let’s take a look at each.

Proprietary SDR applications

Proprietary apps are those that are designed by the SDR manufacturer and provide native plug-and-play support for the SDR you choose. Proprietary apps give priority support to their own SDR, but some are compatible with other SDRs––or can, at least, read spectrum recordings from other SDRs. Most popular SDRs have a proprietary application. Here are examples of a few proprietary apps:

WinRadio App for the WinRadio/Radixon line of SDRs
Perseus Software Package for the Microtelecom Perseus
SDR# App for the AirSpy line of SDRs
SDRuno App for the SDRplay series of SDRs
FDM-SW2 App for Elad SDRs
SpectraVue App for the RFSpace line of SDRs
SmartSDR App for FlexRadio SDR transceivers

Free third party SDR applications

Free third party applications are incredibly popular and some even offer performance and feature advantages over proprietary applications. Third party apps tend not to be associated with any one particular manufacturer––SDR# being a noted exception––and tend to support multiple SDRs. I’m a firm believer in supporting these SDR developers with an appropriate donation if you enjoy using their applications.

HDSDR is a very popular application that supports multiple SDRs and spectrum file formats. The layout is simple and operation straightforward.
SDR Console is a very powerful and popular application. Like HDSDR, it supports multiple popular SDRs. It is my SDR application of choice for making audio and spectrum recordings.
SDR# runs AirSpy SDRs natively, but also supports a number of other receivers including the venerable RTL-SDR dongle.
Linrad (Linux)
SdrDx (MacOS and Windows)
Gqrx SDR (Linux)
SDR Touch is a popular SDR application for Android devices (Android)
iSDR is one of the only SDR applications currently available for iOS devices. Its functionality is somewhat limited. There are other SDR applications in the works, but at the moment these are in development stages only. (iOS)

Paid third-party apps

Paid third-party apps represent a tiny fraction of the SDR applications available on the market. Indeed, at time of posting, the only one I know about that’s currently on the market is Studio 1, which has been the choice for those looking for an alternative application to the Microtelecom Perseus Software Package.

Web browser-based SDR applications

The KiwiSDR browser-based application

This is, perhaps, one of the newest forms of SDR applications. While a number of SDR applications (like SDR#, SDR Console and the Perseus Software package) allow for remote control of the SDR via the Internet, there are actually few applications that are purely web browser-based. At the time of this writing, the only one with which I’m familiar is the KiwiSDR application, which allows both the SDR owner and (if set up to do so) anyone else in the world to operate the SDR as if they are at the SDR’s location. In fact, the KiwiSDR only has a web browser-based application, there is no downloadable application. It will allow up to four simultaneous users, and the experience of using a KiwiSDR locally or globally is nearly identical. If you would like to use a KiwiSDR, simply visit http://SDR.hu or https://sdr.hu/map and choose a remote location.

[Note that if you like web-based SDRs, I highly recommend checking out the University Twente WebSDR located in the Netherlands.]

Choosing an SDR

In Parts Two and Three of this primer, we’ll take a closer look at some of the SDRs currently on the market; prices range anywhere from $15 to $6,000. As you can imagine from such a price range, these are not all created equally.

But first, ask yourself what your goal is with your SDR. Do you want to monitor ham radio traffic? How about aviation communications? Follow pirate radio? Listen to a range of broadcasters? Pursue radio astronomy? Is your dream to set up a remote receiver?

Whatever your flavor of radio, you’ll want to keep some of these needs in mind as you explore the SDR options available to you.

Budget

Be honest with yourself: how much are you willing to spend on an SDR? While entry-level SDRs can be found for anywhere from $15-50 US, a big leap in performance happens around the $100 mark. If you’re looking for benchmark performance, you may need to appropriate $500 or more. Whatever you choose, keep in mind that SDRs are only as good as the antennas you hook up to them. Set aside some of your budget to purchase––or build––an antenna.

Compatible applications

As mentioned above, not all SDRs are compatible with anything beyond the OEM/proprietary application. If you have a choice third-party application in mind, make sure the SDR you choose is compatible with it.

Frequency range

If you want an SDR that covers everything from VLF/longwave up to the microwave frequencies, then you’ll need to seek a wideband SDR. Each SDR manufacturer lists the frequency ranges in their specifications sheet. It’s typically one of the top items listed. Modern wideband SDRs can be pretty phenomenal, but if you never plan to listen to anything above 30 or 50 MHz, for example, then I would advise investing in an SDR that puts an emphasis on HF performance. Check both specifications and user reviews that specifically address performance on the frequencies where you plan to spend the bulk of your time.

Recording and processing bandwidth

The new SDRplay RSPduo can display up to 10MHz visible bandwidth (single tuner mode) or 2 slices of 2MHz spectrum (dual tuner mode)

If you plan to make either audio or spectrum recordings, or if you plan to monitor multiple virtual receivers, pay careful attention to an SDR’s maximum recording and processing bandwidth. This bandwidth figure is essentially your active window on the spectrum being monitored. Your active virtual receiver frequencies will have to fall within this window, if you’re making simultaneous recordings. In addition, this figure will determine the maximum bandwidth of spectrum recordings. Some budget SDRs are limited to a small window––say 96 kHz or less––while others, like the Elad FDM-S3, can widen enough to include the entire FM broadcast band, roughly 20 MHz!

Portability

AirSpy’s HF+ was introduced late 2017. Don’t be surprised by its footprint which is similar to a standard business card to its left–this SDR packs serious performance!

If you plan to take your SDR to the field or travel with it, you’ll probably want to choose one that doesn’t require an external power supply. Most late-model SDRs use the USB data cable to power the unit. This means you won’t need to lug an additional power plug/adapter or battery. Still, many professional grade SDRs require an external power supply.

Recording features

If you plan to make spectrum recordings, determine whether you have many options to set the unit’s processing bandwidth. Some SDR applications have robust recording functionality that allows for both spectrum and audio recordings, including advanced scheduling. Some applications don’t even have audio recording or spectrum recording capabilities. Test drive the application in advance to check out their recording functionality. Of course, if recording is your main interest, you’ll also want to set aside some of your budget for digital storage.

Know your goal!

If your goals are somewhat modest––perhaps your budget is quite low, you simply want to familiarize yourself with SDR operation prior to making a bigger purchase, or you only want to build an ADS-B receiver––then you might be able to get by with a $25 SDR dongle. If you plan to use your SDR as a transceiver panadapter during contesting, then you’ll want to invest in a unit that can handle RF-dense environments.

Identify exactly what you’d like out of your SDR, and do your research in advance. Note, too, that many popular SDR models have excellent online forums where you can pitch specific questions about them.

Scoping out the world of SDRs

Three benchmark receivers in one corner of my radio table: The Airspy HF+ (top), Elad FDM-S2 (middle) and WinRadio Excalibur (bottom).

Now that we have a basic grasp on what SDRs are, what components are needed, and what we should research in advance, we’ll look next at some of the SDR options available to us. In Part Two, we’ll look at budget SDRs; those under $200 US in price. In Part Three, we’ll survey higher-end SDR packages.

Stay tuned for more in Part Two (October–click here to read) and Part Three (November–click here to read)! I’ll add links here after publication.

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A review of the Tecsun R-9012 shortwave radio

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Many thanks to SWLing Post contributor, Laurence Neils, who shares the following guest post:

A review of the Tecsun R-9012

by Laurence Neils

I have cheap radios. I can’t really justify buying more expensive ones given how much time (not all that much) I spend listening to the short wave broadcasters. The consequence of this is that, when I do listen to shortwave stations, I have the rather standard ultraportables to listen on.

My go-to radio is the Tivdio V-115, which has pulled out quite nice reception for me, and offers several functions I like a lot. However, it was missing one that interested me the most: analog or analog-like tuning. If I want to listen to something, I either have to know its frequency and try it, or I have to let the radio do an automatic scan. While it’s quite good at pulling out stations and letting me hear them, it can take a few minutes to do a full scan, and canceling it doesn’t result in the part scanned so far to be stored. Very few stations I am interested in hearing are convenient to jump into several minutes after they start (my interest is in spoken content rather than music, and neither news nor stories make a ton of sense if the introductory information was not heard).

From a recommendation here on the SWLing Post, I chose to purchase a Tecsun R-9012 radio to help me do a convenient scan, which is useful because it allows me to find stations without knowing their frequency, and leaves me to not remember all seventy frequencies a certain broadcaster is using this year.

Physical Description

When I bought my Tecsun R9012, it arrived quite quickly from Amazon. It included a short manual, whose contents could be loosely paraphrased as “insert batteries and turn on”. Other than that, the radio is all that’s there.

The R9012 is relatively small, but not as thin or compact as the Tivdio, which will be my main comparison unit for this review. It is your basic rectangle form factor, and about the size of the small tape recorders that were the last to be phased out for portable recorders. It would be easy enough to put this in a backpack, jacket pocket, or glove compartment, but you have no chance comfortably fitting it into a standard pocket. On the back, there is a flip-out kickstand that can hold the radio at about thirty degrees from horizontal and the battery compartment. This radio is powered from two AA batteries.

The right side of the R9012 contains the analog tuning knob, which I will discuss quite a bit later, and the power switch, which is not connected to anything else (not integrated into the volume knob or mode selector).

The left side gives you a 3.5mm audio out jack. This supports all the headphone types I’ve tried. One benefit of this radio is that headphones with integrated microphones, such as the ones that come with the iPhone as well as various sets that are intended for phone use, will work with it. Some other radios won’t work well with that type of headset. The Tivdio, for example, will play through the headphones but forgets to turn off the speaker if there is a microphone on them, making the headphones pretty much pointless.

Next to that jack is a power port, supposedly to recharge the batteries. A connector for this is not included, nor do they seem to sell one. I suppose the theory is that you might already have a suitable one in that box of old cables we all have, but I can’t see this as a particularly useful feature given the RFI you’ll get if you connect a radio directly to the mains to recharge. Above the ports is the volume knob, which is a very basic analog one, and then the wrist strap, which is integrated into the case. There doesn’t seem to be a way to remove or change it, should you desire that.

On the front of the radio, the speaker takes up the left half. This is fine for standard listening, but don’t expect wonders of audio fidelity. On the right half, there is the twelve-position mode switch (from left to right, FM, MW, SW from low to high frequency) and the tuning display.

FM performance

The Tecsun has a standard FM function, with stated coverage from 76 to 108 MHz. This is the leftmost position on the mode selector. The band is not divided into multiple switch positions, meaning that stations will be relatively packed into dialing space when compared to shortwave, which is spread across ten bands.

I didn’t buy this radio to use it for FM. I have very little interest tuning for FM stations. Some people may enjoy the experience of manual tuning for a station they can locate quickly, but I’m not one. I can easily type the frequency I want on my Tivdio, and I intend to keep doing that for FM. I mostly intended to test FM performance on the R9012 because I was curious to see whether there would be anything audible in the 76-87 MHz section. I know that our TV standards have switched off using analog audio, so I assumed there would be nothing, but I’d never formally put that to the test.

FM on the R9012 has problems. In fact, it has a lot of problems. Among other things, the FM process on this radio doesn’t seem to have a very good idea where things are. I’d be tuning through looking for some station and I’d find it…only to see that I was in a completely foreign part of the spectrum where that station had no business being. It seems that, unless you’re very focused in on a station, the R9012 is liable to pick up some other broadcast and layer them on top of each other. Never mind that the broadcasts have nothing to do with each other and aren’t anywhere near each other on the band. If you have a specific station you want, you can tune to it and have no problems. If you want to see what’s there, you’ll have a very fun time listening to stations that you might want to listen to, only to find that that was an image, you’ve lost it now, and you can’t find it again.

Sometimes, I managed to find a part of the spectrum that gave me three different images simultaneously. Ironically, the broadcast I intended to use as my landmark, the local classical music broadcast, which is located very close to the middle of the FM spectrum, was strong enough or at a coincidental frequency that I identified images of it at six different places on the scan, in addition to where it should be. So I got my answer about 76-87 MHZ. According to the R9012, there’s a lot of signal there. It’s just coincidence that it sounds exactly the same as standard FM broadcasts with extra static.

FM performance gets worse: this radio is extremely sensitive to location.

In order to get nice reception, you have to have the radio in a good position. This seems to be completely random. Standing up so the antenna lies flat on the top, but is not extended produces almost silence. Lying down so the antenna is touching the table (not a metal table) or chair (not a metal chair) causes most signals and images to come through quite clearly. Extending the antenna to medium length helps reception. Extending it all the way introduces a lot of interference. On FM, volume also changes a lot. We may reasonably expect for the signal to change if we connect something conductive to the antenna by, say, touching it with our conductive fingers. Maybe reception will get more static, or maybe it will in fact improve. What we don’t expect is for the broadcast to switch from comfortable volume to let’s see if we can get you some tinnitus volume. Unfortunately, that’s sometimes what happens on FM if you touch the R9012’s antenna. Or tilt it a bit in the wrong direction. This doesn’t seem to happen much if it is tuned onto a station, but if it is anywhere in the middle or if there’s some static, the volume change is very noticeable, in that it makes you want to get the radio off as soon as possible.

In summary, this radio just can’t really do FM. If your other radios are broken, you’ll be fine by using this, but don’t buy it if you intend to do FM things.

Mediumwave performance

The MW frequencies are mostly there, with stated specs including from 525 to 1610 kHz. While there are broadcasts between 1610 and 1710 KHZ, that’s not a ton of the spectrum. I don’t have much interest in MW. I tested the radio’s performance, and it seems fine. Strong stations come in loud and clear. Stations that have low broadcast powers are easy to tune in. I was able to get some skywave MW in here as well, but I really don’t have any interest in that. I was able to verify, however, that the terrible effects that plague FM performance don’t appear on MW. I got no images of distant stations, no rapid volume switches, and the position of the radio doesn’t seem to affect MW reception all that much. Perhaps this is due to the different antenna that most radios employ in tuning MW. However, the manual doesn’t say whether this radio has such an alternative antenna and I haven’t gone to the effort of disassembling it to find out.

Shortwave performance

Once again, the crazy stuff seen on the FM band doesn’t appear during shortwave listening. I was able to tune in quite a few stations, although this probably isn’t a DX-capable device unless you’re willing to go out into RFI-free areas. That sounds enjoyable, but it’s not really my thing. When I got signal, it came in quite clearly. I got very little interference from the device itself, although it does seem quite susceptible to RFI from power lines. Of course, so is everything else, but if you put its antenna closer to a line, you’d know it.

Frequency coverage

Shortwave is covered in ten bands that allow access to the more populated areas of the spectrum, but have many gaps. Certain descriptions claim that the radio has coverage from 3.90 to 21.85 MHz. This is so misleading I’d be willing to call it a lie. The actual ranges are as follows:

SW1: 3.7 – 4.10Mhz
SW2: 4.75 – 5.06Mhz
SW3: 5.95 – 6.20Mhz
SW4: 7.10 – 7.30Mhz
SW5: 9.50 – 9.90Mhz
SW6: 11.65 – 12.05Mhz
SW7: 13.60 – 13.80Mhz
SW8: 15.10 – 15.60Mhz
SW9: 17.55 – 17.90Mhz
SW10: 21.45 – 21.85Mhz

So what if most signals are in there somewhere? Those gaps are very large. For example, the only broadcast frequency for WWV that would be covered on this set is the 5MHZ one. 10, 15, and 20MHZ are all located in various gaps on the bands.

This turned out to be quite annoying. I know that these are standard areas of the spectrum, in which people place a preponderance of broadcasts, but the fact remains that a lot of broadcasts occur between the bands on this set. I checked the A18 shortwave schedule to identify how crazy I was. Of the 5530 broadcasts that were listed between the limits of 3.90 to 21.85 MHZ, 1870 of them or 33.8% of the total, are outside the range of this set.

It strikes me that the largest band on this radio covers only 500 kHz of space, whereas the smallest gap between bands covers 750 kHz. In many cases, bands cover only 100 kHz of bandwidth. While I guess it’s better that they’re there rather than their being completely absent, perhaps some effort could have been done to open that up a bit more. I quickly analyzed where missing signals were, and if Tecsun could extend the 5.95-6.20 MHz band down to 5.8 MHz, 7.10-7.30 up to 7.60 MHz, expand the 9.5-9.9 band, and give an extra 50 kHz to the 11.65-12.05 band, most of the missing spectrum, nearly a thousand broadcasts, would be brought back into coverage. This could be done and still keep the maximum band width at 500 kHz. Therefore, as they didn’t seem to feel this an important issue, it falls to me to consider it so.

Manual tuning

So I bought this to tune manually. It stands to reason that I should review how well it does that.

The analog dial is on the right, and protrudes outward. Once again, the knob does its job, but not all that well. It was very easy to use this to pan through the spectrum and pick up stations, but the wheel doesn’t make it all that easy to do so quickly. You have to turn it by grasping, as the wheel has a fair bit of resistance. I don’t doubt that this feature helps to keep from knocking it off frequency, but you have to use two fingers to rotate freely, and that slows the process down. Meanwhile, the wheel has a rather disconcerting way of stopping, where the wheel seems to have hit an obstruction. However, this essentially increases the resistance, rather than feeling like a barrier. It’s noticeable, but it feels like something’s blocking the turning mechanism, rather than that the mechanism has reached its limit. Actually, it is possible to keep turning the dial, which I assume will eventually damage something, but if you’re not used to how it feels, you may do so without realizing that you’re not actually going anywhere.

The wheel has quite a bit of travel. On my set, it will rotate about three full turns. I believe this is necessary because all of FM, including the standard and Japanese bands, is in one section. Therefore, the wheel needs to be able to turn a lot in order to separate those stations. However, this means that panning over a shortwave band that covers at most 500 kHz of spectrum includes a great deal of panning over static. This works to scan quickly, but there are undoubtedly even faster ways to do so.

Conclusions

It’s a radio. It will pick up stations and make noise. In that, it works. However, this isn’t exactly a great set. The $22 price tag may forgive some of its flaws but not all of them.

Radios like the Tivdio models cost similar amounts and cover the spectrum more fully with some extra features. When I purchased this model, I expected the lack of features to be made up by convenient scanning over shortwave, relatively good sound, and relative disposability. I got enough for me to keep the set, but nothing more.

Pros:

Mediumwave is rather sensitive for those who enjoy listening to those signals.
Radio has a kickstand and the antenna can be rotated freely.
Radio supports headphones with inline microphone.

Cons:

FM is plagued by images of other stations that should not be there. This is rather bad.
FM is far too sensitive to antenna position.
Shortwave coverage, while it includes most of the spectrum in use, has big gaps that are actually being used by a lot of broadcasters.
Analog tuning works, but not really well. The knob can turn but does so with effort.

Would I recommend people to purchase this? Probably not.

Those who have higher-priced devices will get nothing from this. Those getting into the hobby aren’t going to get a ton of benefit from this, because tuning on shortwave requires enough familiarity with dial position that they may spend too long figuring it out. It would be useful on FM only if most other radios have been broken. It’s not even that good as an emergency set because of the FM sensitivity problem.

If all you want is analog tuning over the bands that are provided, the radio will do it for you. If you want more, buy something else.

Thanks for sharing your evaluation Laurence. Thanks for focusing on one of the points that is often overlooked with analog radios: the frequency coverage on various shortwave bands. The R-9012 does seem particularly segmented.

Tecsun R-9012 retailers:

Amazon.com (affiliate link)
eBay

Post readers: Do you own the R-9012? What are your thoughts? Please comment!

Do you like the SWLing Post? Consider supporting us via Patreon or our Coffee Fund! Thank you!

Dave reviews the Icom IC-R30 Handheld Wide Band Receiver

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The new Icom IC-R30 handheld wideband receiver at the 2018 Hamvention.

Many thanks to SWLing Post contributor, Dave Zantow (N9EWO), who notes that he has published his comprehensive review of the Icom IC-R30 handheld wideband receiver.

Click here to check out Dave’s review.

Based on Dave’s evaluation, it sounds like this is one of the better wideband radios, although like similar models, its utility in the HF and mediumwave bands is somewhat limited. He gives the R30 good marks for AGC and notes a lack of spurious emissions on MW. Unlike other wideband handhelds, he noted no mediumwave stations overloading the HF bands. With the unit connected to an external HF antenna however, intense overloading occurred on these bands.

As I tell anyone considering a wideband handheld, don’t buy it with the intention of logging weak signal DX on the HF bands–it’s just not a great receiver for this. It shines on those higher frequencies starting in the VHF band and moving up.

Thanks for sharing your review, Dave!

Gary pulls apart and examines the XHDATA D-808

10 Replies

Many thanks to SWLing Post contributor, Gary DeBock, who shares the following report of the XHDATA D-808:

XHDATA D-808 AM-LW-FM-SW-AIR Portable- Tech Report

by Gary DeBock

The XHDATA D-808 portable is an AM-LW-FM-SW-SSB-AIR band model which has already been the subject of many excellent reviews. Until recently the model was not marketed to North American purchasers, but recently a couple of Chinese sellers have started soliciting North American buyers via eBay listings.

My own interest in the model was in comparing its AM Band performance to that of the best performing Ultralight radios– specifically the CC Skywave and Skywave SSB models. Although the D-808 is slightly larger than the 20 cubic inch limit for Ultralight radios, its size and weight make it very convenient to take along as a “travel portable,” specifically as an SSB-enhanced model capable of checking transoceanic station carrier strength on exotic ocean beaches. The Skywave SSB model can also do that– but at a $169.99 list price, compared to the $112.86 (plus $10 shipping) cost of the D-808. In addition, none of the published D-808 reviews seemed to have any information about internal components like the loopstick, or Si4735 DSP chip.

My first test was to compare the stock Skywave SSB model with the D-808 in fringe AM station reception. The Skywave SSB model has a reputation of being one of the most sensitive Ultralight radios, but the D-808 clearly outperformed it on both low band fringe station (550-KARI) and high band fringe station (1700-City of Auburn TIS) reception. The D-808 couldn’t quite hang with a 7.5″ loopstick Skywave model, but that only made me curious about how the same modification could enhance the D-808. So… it was time to disassemble the D-808, and find out why its loopstick was such a superior performer.

The D-808’s 3 7/8″ (98mm) loopstick is shown adjacent to the 2 3/4″ (70mm) loopstick of the CC Skywave models. The D-808 is much easier to disassemble than the CC Skywave models, though, so enhanced loopstick transplants should prove to be quite popular in the D-808.

The D-808 loopstick is 3.7/8″ (98mm) long, while that of the CC Skywave SSB model is only 2 3/4″ (70mm) long. Other reviewers have noted the excellent performance of the D-808 on the AM band, and this is probably one of the main reasons. The SSB mode operates very similar to that of the Skywave SSB in providing a quick check of carrier strength on weak AM band targets– the LSB mode can be set to +55, and the radio tuned to different frequencies to check fringe station carrier strength. This can provide a real-time check of propagation changes during time-limited propagation openings for live ocean beach DXing with Ultralight radios or other portables (or with the D-808 itself, if desired).

The D-808’s Si4735 DSP chip was initially used in the Eton Traveler III Ultralight radio model, which was fully reviewed in the 2015 Ultralight Radio Shootout (where it won top honors for MW sensitivity). The D-808 augments that capability with a significantly longer loopstick, plus multiple DSP filtering selections. As such, the D-808 in stock form should be a very superb performer.

The Si4735 DSP chip has markings of “3560, DCUL, .738” and provides a wide range of AM bandwidth choices for the Medium Wave DXer (6K, 4K, 3K, 2.5K, 2K, 1.8K and 1K). These perform very well, and as with the other DSP-enhanced portables, the narrowest bandwidth (1K) provides the most sensitive AM band reception.

In construction very similar to that of the CC Skywave, the D-808 separates into two main circuit boards, connected together by a plug-in ribbon cable. One strange quirk is that the Si4735 DSP chip is located on the RF board (close to the center right edge). The Si4735 DSP chip is also used in the Eton Traveler III Ultralight radio, and although that model lacks the multiple DSP filter selections of the D-808, is has been the subject of highly successful 7.5″ loopstick transplant modifications– proving that such enhanced Medium Wave and Longwave loopsticks will perform very well in the new, Si4735 chip- powered D-808.

Disassembly of the D-808 model is fairly straightforward in comparison to the CC Skywave models, and the technician doesn’t need to memorize a detailed reassembly protocol in order to perform a routine loopstick transplant operation. Neither C.Crane nor XHDATA are likely to show any sympathy to someone botching up an antenna transplant, so you need to be confident that that your skills are superior to those of the company technicians before taking the plunge. In the CC Skywave and CC Skywave SSB models various parts fit together like a puzzle, but the D-808 isn’t like that. It should prove to be a fairly popular model for enhanced MW and LW loopsticks.

Those considering a purchase of the D-808 should be advised that its type 18650 Li-ion 3.7v battery is not commonly available at most stores, and that Postal regulations supposedly forbid shipping these batteries through the mail. One of the eBay sellers (harelan ecommerce) did manage to ship me two of the standard XHDATA type 18650 batteries through the mail (along with two new D-808 models) but if your seller won’t do this, you can still purchase the batteries on eBay. Some of the 18650 batteries sold on eBay have a flat positive terminal which won’t contact the D-808 cabinet’s positive battery connector terminal, but in such a case you can simply insert a #8 lockwasher in between the two, and the arrangement will be very secure. From that point on you can simply recharge the battery with a USB terminal connector.

Thank you for sharing this technical overview of the XHDATA D-808, Gary! I’m looking forward to the antenna mods you’ll no doubt make to this compact DX machine!

Click here to read other posts about the XHDATA D-808 and here to read posts by Gary DeBock.

A review of the SDRplay RSPduo 14-bit dual tuner SDR

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The new SDRplay RSPduo

Moments ago, I posted a press release from the UK-based software-defined radio manufacturer, SDRplay, announcing their latest product: the RSPduo: a 14-bit Dual Tuner SDR.

I should start with the disclaimer that, not only was I sent an RSPduo to review and evaluate, but SDRplay has been a supporter of the SWLing Post for a few years now. You’ve no doubt seen their ads in the upper right corner of our site. After I reviewed their first SDR (the RSP1) I discovered that SDRplay––all of their staff and supporters––welcome constructive criticism and even invite frank discussions. They’re a company with integrity. No doubt, this is why I agreed to alpha- and beta-test their SDRs. Fortunately, I’ve not been disappointed.

As a company, moreover, SDRplay breaks the mold––and in very good ways:

SDRplay is a small company that employs actual radio enthusiasts. Their designs and software cater to DXers, SWLs, hams, scanner enthusiasts, amateur astronomers, experimenters, and makers, among others.
SDRplay designs and builds their products in the United Kingdom. No doubt they could increase their profit margin by using manufacturing centers in China, but they choose not to do so, to the benefit of their products.
The quality of the company’s products is, at least to date, excellent.
SDRplay’s product pricing is nonetheless quite affordable

That last item, in particular, is a head-scratcher. Considering these facts, how does SDRplay still manage to keep their pricing so competitive? I only wish I knew. When the company released the RSP1A last year, I had already spent a few months with alpha and beta units, mulling over their respective merits (and there were many). So I was simply gobsmacked when they announced that the price would be just $99 US. I rather figured the company was leaving money on the table, although I was pleased to announce this price to my readers here.

Fast-forward to two weeks ago: I received the new RSPduo to review. And the price this time? $279 US. While this is currently the priciest product in the SDRplay line, let’s go over what makes this SDR special…and why I still think SDRplay may be leaving money on the table.

Introducing the SDRplay RSPduo

The RSPduo is unlike any other SDR in the SDRplay product line, and, indeed, unlike most of the budget SDRs currently on the market.

As “duo” implies, this RSP features dual independent tuners, both piped through a single high-speed USB 2.0 interface. With the RSPduo, you can explore two completely separate 2 MHz bands of spectrum anywhere between 1kHz and 2GHz.

SDRplay lays out several use-scenarios in their press release:

The ability to simultaneously receive on two totally independent 2 MHz spectrum windows anywhere between 1 kHz and 2 GHz
Simultaneous processing from 2 antennas enables direction-finding, diversity, and noise-reduction applications
Ideal for cross band full-duplex reception, e.g. HF + VHF, or VHF + UHF
Simultaneous Dump1090 and VHF ATC reception
Simultaneous monitoring and recording of 2 ISM bands
Use SDRuno to seamlessly control and manage the dual tuner in a single environment.

Externally, the RSPduo bears a strong resemblance to the RSP2pro. Internally, however, it’s quite different.

Besides featuring a second independently controlled tuner, the RSPduo also sports 14 bit ADCs and a completely re-designed RF front end, which enhances receiver selectivity and improves dynamic range.

In short, the RSPduo is like having two SDRs in one.

Performance

I received the RSPduo during a very busy time of the year: the build up to the Hamvention in Xenia, OH.

One of the first things I noticed about the RSPduo is its weight. When I picked up the package from SDRplay, I could tell it weighed at least twice that of the RSP1A. One reason for the extra heft is that the RSPduo, like the RSP2 Pro, has a metal enclosure. I’m willing to bet the RSPduo also has more shielding––adding even a little extra weight.

I’ve had the RSPduo on the air for more than a week now, and have checked out all of its major functions and begun to learn the nuances of navigating the dual receivers in the latest version of SDRuno.

SDRplay will, I feel sure, post a primer video on using the various dual tuner functions in the coming weeks.

Installation of the software, even in pre-production, was totally a “plug-and-play” experience. Simply install the SDRuno software package with the RSPduo disconnected from the USB port. Plug in the RSPduo, and wait for the USB driver to load, then open SDRuno. That’s it. You’re on the air!

As I’ve indicated, the RSPduo is really like having two RSP1As in a single RSP2 Pro package. One of these dual receivers––the master––can utilize either a standard 50 ohm SMA antenna port, or a Hi-Z port. The second receiver uses one 50 ohm SMA antenna port just like the RSP1A.

I much prefer using the Hi-Z port for everything longwave and mediumwave. I did hook up both antenna ports on the master receiver, however, and switched back and forth between the two. At least in my antenna setup, I feel like the Hi-Z option lends itself to improved sensitivity on these bands. It’s not a dramatic difference––indeed, looking at the spectrum display one barely notices the difference––but my ears told me the noise floor was lower and signal strength slightly better with the Hi-Z port. Above 2 MHz, the Hi-Z port is not prefered since it lacks the same level of RF pre-selection as the 50 ohm ports provide.

Unlike the Hi-Z port with the RSP2, the RSPduo treats the Hi-Z port more like an auxiliary antenna port. When I employed the Hi-Z port in the HF bands, I did notice small spurious noises, but this might have been due to my antenna port configuration here in the shack (my Hi-Z connector is simply attached to the shield and center conductor of my coax).

Again, however, for anything above 2 MHz, SDRplay suggests using the 50 ohm ports.

How to set up dual receivers on one screen/monitor

Listening to the FM broadcast band on the main receiver and Voice of Greece shortwave on the second receiver.

One of the first things I was eager to do was to run the dual receiver functionality on one monitor. Although SDRplay makes this a pretty simple process in the latest version of SDRuno, I still stumbled a bit as I learned to navigate the controls.

Here’s a quick primer to get both receivers on the air on one monitor/screen:

First, open SDRuno in “single receiver mode” (the typical SDRuno default).

Next, click on the “RSPduo mode” button and select one of the modes. In this case, I’m not running the ADS-B application, so I’ll choose “DUAL (NORMAL)”.

Now, to format the “Master” receiver windows so they only use the top half of the monitor, click on the OPT button.

Select “Auto Layouts” and “RSPduo Master.”

If you’ve followed these steps with me, your screen should look something like this:

Now you’ll want to start the second receiver. Do this by opening the SDRuno application again (as if you were opening SDRuno for the first time). Make sure you’ve selected your RSPduo if you have more than one RSP connected.

The new instance of SDRuno will fill the entire screen by default, so you’ll need to format it to occupy the lower half of the screen.

Simply click on the OPT button again, select “Auto Layouts,” and “RSPduo Slave.”

Your full screen should now look something like this:

Now you can start using both receivers, but you’ll have to always start the “Master” receiver first. In fact, the “Master” receiver must always be active in order to operate the “Slave” receiver. You can always close the “Slave” receiver without affecting the “Master” receiver; however, if you close the “Master” receiver, you will effectively close both receivers.

Again, I fully expect SDRplay will soon produce a demonstration video showing how you can navigate SDRuno’s new dual-receiver functionality.

Comparisons

As I’ve mentioned in most previous SDR reviews, I do like to take a considerable amount of time to set up SDR comparisons.

Herein lies the difficulty of reviewing an SDR’s performance. Because the user has so much power to control variables and thus shape the receiver’s function, it’s actually quite hard to make an “apples-to-apples” comparison––insuring that all important filters, gain controls, DSP, etc., are as close to identical as possible.

One tool that helps me do this is SDR Console, since it can control a number of SDRs and receiver parameters can be set up identically. Unfortunately, the RSPduo is so new, SDR Console doesn’t yet support it.

I did use SDRuno to compare the RSPduo with the RSP1A. Fortunately, I could actually run two separate instances of SDRuno simultaneously (and on different monitors, in my case). Both were hooked up to the same antenna via my ELAD ASA15 antenna splitter amplifier.

The RSPduo’s improved dynamic range gives it an advantage in terms of noise floor, sensitivity, and selectivity.

The improved performance is not dramatic––but I understand it might be especially detectable to those who want a receiver with a more robust front end.

In fact, the RSPduo’s 50 ohm coaxial ports have quite an array of automatically configured front end filters:

Low Pass

2 MHz Band Pass
2-12 MHz
12-30 MHz
30-60 MHz
60-120 MHz
120-250 MHz
250-300 MHz
300-380 MHz
380-420 MHz
420-1000 MHz

High Pass

1000 MHz

And an array of notch filters

FM Notch Filter:

>30dB 77 – 115MHz
>50dB 85 – 107MHz
>3dB 144 – 148MHz

MW Notch Filter:

>15dB 400 – 1650kHz
>30dB 500 – 1530kHz
>40dB 540 – 1490kHz

DAB Notch Filter:

>20dB 155 – 235MHz
>30dB 160 – 230MHz

The thing is, I live in an RF quiet area, so I can’t fully take advantage of the SDRuno’s more robust front end.

In head-to-head comparisons with the RSP1A, the RSPduo’s performance edge is discernible. Again, I suspect it would be a bit more obvious if I lived in an urban setting with blowtorch stations in the neighborhood. Using the Hi-Z antenna port in the mediumwave portions of the band, the RSPduo has a performance edge over the RSP1A, as well.

Should you grab the RSPduo?

The new SDRplay RSPduo

Anytime a new product hits the market, I ask myself if this is the sort of product that would tempt me to reach for my hard-earned cash.

The short answer? Absolutely! Take my money, please! There is no other sub-$300 SDR on the market currently that has the dual tuner functionality of the RSPduo. Thing is, I’ve only had the RSPdup a couple of weeks–there’s so much yet I want to explore here–especially diversity reception!

But what if you already have an SDRplay SDR? Afterall, the RSP1A was only released a few months ago, and the RSP2 series only a year before that.

Here’s my opinion: If you’re an RSP1A or RSP2 owner who is pleased with this SDR’s performance, I wouldn’t necessarily urge you to purchase the RSPduo simply for the modestly enhanced performance characteristics. SDRplay hasn’t retired the RSP2 and RSP1A designs because each model still holds its own, has a purpose, and obviously enjoys a healthy market.

The RSP1A is the affordable yet high performance entry model in the SDRplay product line. It’s really the best value in the radio world, in my humble opinion, at just $99 US. Som enjoy.

The RSP2 and RSP2pro provide excellent performance, three software-selectable antenna inputs, and clocking features, all of which lend it to amateur radio, industrial, scientific, and educational applications; it is a sweet SDR for $169 or $199 (Pro version). I know of no other SDRs with this set of features at this price point. If I liked the characteristics of the RSPduo, but didn’t really need a dual receiver for my application, I’d probably reach for the RSP2 Pro.

But if you have the original RSP, and like SDRuno and the SDRplay community, then I would certainly consider this an opportunity to upgrade. For $279, you’re getting a dual receiver SDR with excellent performance characteristics that will easily surpass the original RSP––considering that you’re essentially getting two very good SDRs in one.

And if you’re all over the spectrum (aren’t we all a bit––quite literally?) in terms of usage, the RSPduo is a fascinating machine for running, say, an ADS-B receiver while independently using the same SDR box to monitor other parts of the spectrum. Or one can listen for FM DX on one receiver while trying to snag elusive LW DX on the other.

Better yet, the RSPduo only uses one USB port––an important factor if you’re using a laptop or tablet. Of course, having two receivers on two different antennas, while sharing one data port, means syncing them for diversity reception is especially effective. This alone will sway many SDR experimenters in favor of this rig.

I have yet to compare the RSPduo with the brilliant little AirSpy HF+. The AirSpy HF+ is not a wideband receiver like the SDRplay RSP series; it only covers 9 kHz to 31 MHz and 60 to 260 MHz. But if your primary concern is HF performance, the HF+ and its excellent dynamic range will impress you, if you’re anything like me. It’s also a bargain at $199––very hard to beat!

The RSPduo is a good value, in my opinion––and an inexpensive upgrade to a proper dual receiver SDR––so if that’s the sort of thing you’d like to add to your shack, go ahead and bite the bullet!

In fact, I suspect SDRplay will quickly sell out of all of the units they bring to the 2018 Hamvention (SDRplay: pack some extras!). I’m happy to see the company continue to push the price and performance envelope to such exceptional ends. I’m also looking forward to the many applications SDRplay customers (and our readers) find for the RSPduo.

Stay tuned! I plan to post more comparisons in the future.

And if you acquire an RSPduo and find some new and fun applications for it, please share!

Click here to check out the RSPduo at SDRplay.com.

Recommending the Tecsun PL-880 over the Sangean ATS-909X

12 Replies

Many thanks to SWLing Post contributor, Direwolf131, who recently commented on one of the Sangean ATS-909X reviews in the Post archives.

Direwolf131 writes:

I’m a few years after Steve’s comments but I will have a go at it, at least anecdotally speaking. I’ve owned a half dozen Sangean ATS-909’s, which includes two of the 909X’s, and one super-909 from radiolabs. The 909X is the finest looking portable I have ever seen or lain hands upon, and that includes several Sony’s that I still think of as neat looking, I had the white cabinet 909X first and then the much more striking (to my eyes) black cabinet 909X after returning the first one due to rock hard buttons.

They are both extremely attractive, and exceptionally well made, especially by today’s cheap Chinese standards. I must confess that I also still find the original 909’s almost equally neat looking, though not quite sporting the same robustness of build.

The 909x’s sound wonderful on MW & FM, and its a decent performer reaching out to fairly distant FM stations. Unfortunately that is largely the best of the radio, its performance on MW & SW is best described as pathetic, and not just due to being deaf, it has a lot of noise, even when attached to the superb RF systems tuned EMF antenna. The older 909 is also to my experience substantially better then the 909X when matched up to a serious outboard antenna, such as the above EMF, I found this difference especially surprising, its not even close.

The PL-880 from Tecsun blows it away on SW and MW sensitivity, while also offering the superb advantage of genuinely ECSS tuning anything on MW & SW, you cannot decently receive any MW or SW signal via ECSS with the 909X as its SSB can only be fine tuned to 40 Hz, which is terribly disappointing, you can zero beat the little Tecsun easily. serious ECSS capability is to my mind a much more attractive option then a sync circuit, and unfortunately with the beautiful little Sangean 909X you get neither.

I do hope anyone who happens upon this pays attention, because for the money the PL-880 is far and away the better performer, in fact my little 1103 from Degen/Kaito out performs the 909X, as does my Grundig Yacht Boy-400, and my Sangean ATS-803A. Its my great hope that Sangean seriously upgrades these deficiencies in the otherwise gorgeous 909X, its circuitry is noisier than the old 909 and its not nearly not as sterling a performer hooked up to household current and a decent outboard antenna as the old 909, its 40 hz tuning SSB once a great reason to buy a 909, is no longer competitive, especially against the superb PL-880 which again is capable of excellent ECSS even by Icom R75 standards, Sangean would do well to drastically improve the SSB performance of the 909X.

I hope this helps, I liked the original review up top, but again its several years old, and the ATS-909X is now known to be clearly outclassed by the more affordable Tecsun, actually by the PL-660 to boot, I really hope Sangean addresses the issues, its such a beautiful receiver, you just want it to be as good as it looks, unfortunately it’s not!

Thank you for sharing your evaluation and comments!

The Sangean ATS-909X is an interesting radio indeed. Almost everyone loves the design, audio and overall quality of the 909X. Yet performance reviews are somewhat polarizing: some 909X owners claim the 909X has strong performance characteristics on shortwave, while others believe it’s almost deaf. Your findings coincide with mine from the Mega Review where I pitted the ATS-909X against the Tecsun PL-880, PL-660 and Sony ICF-SW7600GR. In that review, where I relied on a whip antenna, the 909X was noticeably less sensitive than the other three competitors. Based on the premium one pays for the 909X, I was surprised.

I have learned over the years, however, that the 909X can handle larger outdoor antennas and doesn’t easily overload. Additionally, the 909X requires a fresh set of batteries for optimal performance/sensitivity. Some users have even modified the radio with a 4:1 impedance transformer–click here to read a post/comments about this mod.

I would love to see Sangean produce an updated/upgraded version of the 909X, but at this point I’m not exactly holding my breath. I’ve heard that they’re slowly pulling out of the market. Hope I’m proven wrong because I’d love to see a new shortwave set from Sangean.

The Professor reviews the XHDATA D-328

8 Replies

Many thanks to SWLing Post contributor, The Professor, who shares the following review of the XHDTA D-328:

First off, this is the best radio I’ve ever operated… that cost me less than ten dollars new. When I saw the promotion on the SWLing Post for free or half price radios, I had to bite, especially because the deal was that the first ten to respond would get a free XHDATA D-328. They told me I was the 15th caller, so I was allowed one for half price. And since they were going for just under fourteen bucks on Amazon, it felt like it was almost free.

Of course, I didn’t expect much. But as they wanted the people who received these free or very inexpensive little radios to leave reviews, I figured the Chinese manufacturers knew there were some good features radio folk might notice. And there are. And I’m not sure if I’ll post part of this brief review on Amazon, but I’ll do so here in this comment.

If you want a radio that will reliably pick up local AM and FM stations and play some MP3 files, this will work, and work pretty well. And it doesn’t sound bad at all for the size. I personally don’t have much love for these new analog-style tuning DSP radios, but I suppose people who aren’t as radio wise as readers of the SWL Listening Post won’t notice the less than poetic effects of moving between stations on these sets. Most probably tune in their desired stations and just listen to it, and this radio does this well enough.

I don’t really listen to FM much, but the XHDATA D-328 seems adequate enough. And with headphones on it sounds quite rich on FM. AM isn’t bad either, but it’s far from selective. I was able to dig out clear channel regional biggies like Zoomer Radio at 740kHz and WHAS at 840kHz in Louisville from here in Brooklyn at night, but in between often easy to find fifty-thousand watt stations like WBBM or CKLW weren’t there. The DSP tuning just defaulted to the next local station like WNYC or WABC when I turned the dial.

Shortwave was worse. Beyond the U.S. powerhouses like WWCR this radio doesn’t seem a very worthy shortwave set for those of us in North America. But I can imagine in that in third world countries where international and local broadcasters still target broadcasts that this radio might be an inexpensive way to access that programming.

I must admit that listening to MP3 music files was kind of pleasing. Again, the audio is really good for a radio at this price point. However you are listening blind, there’s no screen to tell you what you’re hearing, and no shuffle function to make a folder full of MP3s into unique sequences of songs each time. What you get are the songs in the alphabetical order of the file titles, although you do have the option to jump ahead 10 files before or after the one you are playing. So the best use of an MP3 player like this would be to listen to podcasts or whole radio programs with it. What I would do is copy the files onto the SD card and then perhaps number the filenames in the order I would like to hear the shows.

So, for the price there’s not a lot to complain about. People have already mentioned the off-center small kickstand, and that’s a little cheesy. But the tuning thumb wheel moves smoothly thru the imperfect DSP tuning function, and the volume thumb wheel is actually analog which make it much easier to get the exact volume you want out of this radio. But the sliding band selection switch under the tuning scale is a bit worrisome, as I’ve had a few cheap Chinese radios with a switch like this and just normal use eventually rendered them unable to switch bands adequately. This one feels a little bit more stable then they did, but time will tell.

All that said, there are radios that are not too much more expensive than this radio that offer much more in a number of ways. The small and inexpensive analog Tecsun radios from a few years ago are a case in point. Selling for twenty to thirty dollars, those multi-band radios are a little challenging to tune (a stiff thumb wheel on some), and the tuning scale may be a little off and they may drift a little, but the analog tuning is a much better experience. And you can DX with them. I remember listing to All India Radio with a decent signal one afternoon on my Tecsun R-9710.

There’s a lot of similar analog radios which I believe are probably just about the same radio – the Tecsun R-9012, the Tecsun R-911, the Tecsun R-909 and the Kaito WRX-911, among others. Once you get a look at these you’ll recognize other similar radios in this family. I’d say they’re the best really cheap receivers I know of. They generally run between twenty to just over thirty bucks. I believe these radios appeared on the scene in the early 2000s.

I have this fear that they’ll start turning these radios into DSP sets. That would be a real shame, but I’ve heard no mention of that. However I did notice that the marketers of the XHDATA D-328 didn’t even mention that it was based on a DSP chip. And Chinese manufacturers are notoriously not very open about how they are altering radios that they’re putting out, so be aware of that.

As far as MP3 playback, the one radio I would really recommend is the Meloson (or Tesslor) M8 (or the Meloson M7 or S8 if you can find one). It’s simply the best audio you’ll hear in a really small radio, AND you can shuffle the MP3 files in a folder with these. While it only give you the sequential number of the song in the display, it will generate a unique sequence of songs each time you shuffle. Fill a folder on a card full of songs and let it rip. It’s the perfect micro music player if you make a good folder of music. And the DSP radio in these is not bad either. It’s digital, not fake analog tuning, and most AM clear channel targets you can usually find at night in your region will show up on these. They used to go for less than thirty bucks, but right now I see they cost close to fifty dollars.

Two other radios I have that I can recommend for MP3 playback, are the Tecsun ICR-110 and the Tivdio V-115. Neither one offers playback shuffle, but they will play the files in alphanumeric order just fine. But they both have a cool feature in that you can press a button and record the broadcast you’re hearing as an MP3 file. And they both also sound great. The Tivdio has incredible sound for a tiny radio, but the ICR-110 is even more impressive. I believe it has the same speaker setup as the much more expensive Tecsun PL-880 and it also has similar warm and clear audio.

The reception with the V-115 is OK, nothing stellar, but the ICR-110 is kind of a monster on medium wave. I’ve been impressed. The ICR-110 is rather big compared to the other radios I’ve mentioned, closer to the PL-880 in size, but quite a bit lighter. The ICR-110 used to be cheaper, but can be found for around forty bucks. The Tivdio V-115 still goes for just under twenty if you look around. A bargain. Tecsun, Tivdio, Degen and other Chinese manufacturers have all sorts of inexpensive radios for sale out there, and others I haven’t used or mentioned might be quite good as well. If one appeals to you, do a little online research.

Of course, since I’m talking about small and inexpensive radios I should mention that the Tecsun digital DSP sets like the PL-310ET, the PL-360, PL-380, PL-390 and other variations are all amazing inexpensive radios that will run you around 35 to 50 bucks. The ultralight DX community loves these things, and for good reason. And there’s a version of the PL-390 that plays MP3 files from an SD card and another that offers bluetooth playback. No, none are perfect, but they’re solid sets, and all would have been dream radios thirty years ago.

So, that’s my evaluation of the XHDATA D-328, well worth fourteen dollars, but for a few dollars more you can get radios with similar features that do much more. It’s small, it doesn’t sound bad, and it’s fairly well-built. It will pick up all your favorite local stations and play all your MP3 podcasts effortlessly. Not bad. Like I said, it’s the best super cheap radio I’ve ever used.

Excellent review! I’m impressed that the D-328 has enough AM performance to grab some night time clear channel stations. It’s disappointing, however, that it lacks performance on the shortwave bands.

Thanks for posting your review–always great to hear from The Professor!

The XHDATA D-328 is available on Amazon.com (affiliate link).

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