Tag Archives: SiLabs

Mechanically-tuned portable DSP radios: a shootout

Three of the five contenders: The Degen DE32, Degen DE321 and Tecsun R-2010D (Click to enlarge)

Three of the five contenders: The Degen DE32, Degen DE321 and Tecsun R-2010D (Click to enlarge)

Following is my premiere shortwave radio column for the January 2014 issue of The Spectrum Monitor digital magazine.  It takes the form of a review–or “shoot-out,” if you will–of a few select mechanically-tuned DSP radios I’ve tested over the years.

While I’m a big fan of print publications, digital publications like TSM offer me flexibility that I can’t get in traditional print: namely, shorter time to publication (thus more up-to-date information) and especially, the ability to embed links and audio as I do here on The SWLing Post. In this case, I’m able to include audio clips which the reader can utilize to compare the radios firsthand (embedded here, as well).

Note: This being my first contribution to a brand new magazine, I thought it would be fitting to begin by explaining why I still believe in shortwave radio…I mean, how could I resist? I guess I’ll always be a shortwave evangelist at heart.

Hope you enjoy.


First:  why I still believe in shortwave

SP600Dial3While I’ve been blogging about shortwave for several years now, I simply can’t tell you how many times I’ve received an email asking doubtfully, “This seems like a fun hobby, but isn’t shortwave radio dead?”

My response?  No way!  Here’s why.

I once had the truly good fortune to be interviewed by Gareth Mitchell, host of the BBC World Service technology program Click. For once, I made a point of listening to this interview that featured me––always a bit embarrassing––but after all, this was the BBC World Service!

But Gareth’s lead-in to our segment about my shortwave radio-based charity, Ears To Our World (ETOW), truly surprised me:  our non-profit, he said, “distributes portable battery powered devices that can stream audio in real time, all via an intuitive touch interface.”

Wow…how true.  And since that interview, this is exactly how I see shortwave radio, too: not as a forgotten relic of the past century, but as a medium at home in the future with a unique, highly accessible, and yet global reach.  Shortwave radio, after all, requires no apps, no subscriptions, and no mobile phone or Internet connection to deliver information worldwide at the speed of light.

All you need––in short––is a radio.

Shortwave lives!

This column exists to prove to the doubtful that shortwave radio––indeed, radio in general––is not only alive and well, but loud and clear in urban as well as rural settings the world over.   Here, you’ll find in-depth articles that reflect the changing state of shortwave radio:  the technologies, the techniques, and the vast array of content currently available across the shortwave radio spectrum. Best yet, because SWLing (shortwave listening) is what you make of it, you can be part of it:  share your input, so that I can cover (and uncover) shortwave topics you wish to discuss.

So I begin this first column with a little comparison––a shootout––between five newly-popular analog DSP radios.  Let’s find out who’s left standing.

The contenders

We’ll be pitting five models against each other here: the Degen DE321, the Degen DE32, the Tecsun R-2010D, the Kchibo KK9803 and the ShouYu SY-X5. With the exception of the ShouYu SY-X5, all of these manufacturers have in the past produced at least one portable with truly notable performance (the Degen DE1102, 1103, Kchibo D96L and an array of Tecsuns, including the PL 310, 380, 390, 600 and 660).

Moreover––so that you can hear the difference for yourself!––I’ve included linked audio clips for each model. They were all tuned to the same frequency, same broadcast and within seconds of one another.

But first, what is a DSP radio? And why do we need them?

The Silicon Labs DSP chip found in many of these radios.

The Silicon Labs DSP chip found in many of these radios.

Mechanically-tuned DSP

Radio is no longer just your granddad’s medium.  Several years ago, the digital signal processing chip manufacturer, Silicon Labs (SiLabs), altered the entire radio landscape with one little chip. Indeed, most new digital shortwave/AM/FM radios on the market use a SiLabs (or other manufacturer’s) DSP chip as the centerpiece of their receiver architecture.

Using a DSP chip in a fully digital radio makes sense: after all, you have a digital display, digital buttons, and digital encoder. But using a digital chip with a traditional analog display––a mechanically-tuned DSP radio––does that make sense?

SiLabs and a growing number of radio manufacturers and retailers believe the answer is a resounding “yes.” In truth, there are concrete benefits to making this addition; among them:

  • Decreasing production cost of radios by as much as 80%
  • Decreasing R&D costs of new radios dramatically
  • Digital signal processing with the simplicity of analog radio design
  • Reduced power consumption when compared with digital display radios
  • An avenue to make radios more affordable––especially to listeners living in poverty, such as those in developing world settings, who make up a large subgroup of listeners

When I first learned about the implementation of a DSP chip with a mechanically-tuned radio in 2010, I felt like it might be “the” way to make quality receiver performance available and accessible to many.  Now, four years later, several manufacturers have produced mechanically-tuned DSP shortwave radios.  All are available from sellers at a price of under $40 USD. Not bad…

Common review points for mechanically-tuned DSP radios

I’ve now reviewed enough mechanically-tuned DSP-based radios that I’m beginning to note performance commonalities that can only be attributed to the design of the DSP chipset itself, regardless of how these are implemented in each model. So, before the shooting starts, let’s take a quick look at some common review points of the contenders.

Tuning: not quite an analog radio…

I’ve got to begin with the most obvious common review point: namely, tuning.

For those of us accustomed to analog tuning, the DSP/analog combination is, well, completely different and a little quirky. Tuning a traditional analog radio is a fluid process which allows for a certain amount of play; you need not be precisely on a frequency to hear a station, and often you hear a station fade as another pops into the band pass. But when tuning analog DSP, you hear stations and static pass by in comparatively coarse 5 kHz chunks. Especially in radios with tiny analog frequency dials, it makes tuning feel somewhat “sticky” or finicky, and ironically, rather imprecise. You feel like you’re skipping over stations while band-scanning.  And for those accustomed to digital tuning, instead of using buttons to tune in these 5 kHz increments, you’re using a tuning wheel, with no customary “step” response.  Not what you would expect from either digital or analog radio.

But of course, you can locate your station with this method.  It takes a little practice––and a measure of patience––but you’ll adjust to this different method of tuning.  Note that much of this awkwardness may disappear if SiLabs produces a chip with more precise tuning increments, such as 1 kHz steps with decreased muting.

Automatic Gain Control

In all the models I’ve tested so far, the Auto Gain Control (AGC) is a little too overactive when listening to weak AM/SW stations. This results in a “pumping” sound and serious listening fatigue when set on weaker stations. However, on strong stations, all models perform quite well.

Conformity

Since all of these radios are based on the same chip family from SiLabs, you can expect eight shortwave bands: two FM bands, one AM (medium wave) band, and eight shortwave bands. The frequency ranges available to the manufacturer in all bands are identical.

FM

FM performance on each of these radios is above average, and the coverage quite wide––from 64 MHz to 108 MHZ in two FM bands. If you like listening to FM radio, you’ll be pleased with any of these inexpensive models.

And now for some action!

Now, we’ll pit these five radios against each other in an listener’s challenge that will leave the losers in the dust…and the winners clear.

Degen-DE321

The Degen DE321 – Current retail:  $21.00 USD

The DE321 was the first analog DSP shortwave radio on the market. The DE321 is small, slim, über-simple, and fits nicely in the hand. The analog tuning dial takes up more than half of the front face of the radio––a good thing, as the larger the dial, the easier the tuning. Performance-wise, the DE321 holds its own in this crowd; it’s quite reasonable in both sensitivity and selectivity. The DE321 is the most bare-bones radio among the five described here.

Degen-DE32

The Degen DE32 – Current retail: $27.00 USD

The DE32 is the smallest radio of the five. Unlike the DE321, the DE32 is not “just” a radio; it also sports a simple MP3 audio player and a small white LED flashlight. The DE32 has a small built-in speaker which delivers tinny and rather cheap audio, but is okay for a single listener, and fine for spoken-word broadcasts. Audio fidelity is greatly improved with headphones. Performance-wise, the DE321 is slightly better than the DE32 on shortwave.

Tecsun-R2010D

The Tecsun R-2010D – Current retail: $39.00 USD

When I first held the R-2010D, I initially assumed I had found the holy grail among analog/DSP radios:  while the R-2010D is the largest of the five radios, measuring nearly equivalent to my Sony ICF-SW7600GR (not a pocket-sized portable like the others) it nonetheless has a beautiful large analog display (a major plus!), an amply-sized speaker for great portable audio, and a fluid tuning mechanism. To top it off, the R-2010D has a small digital frequency display so that you can verify your frequency. The R-2010D’s AGC circuit handles strong stations well, but clips on weak stations. But the promising R-2010D has one major flaw: terrible selectivity. Indeed, the selectivity is so sloppy, that you will not be able to delineate two strong signals spaced 10 kHz apart from each other.

ShouYu SY-X5

The ShouYu SY-X5 – Current retail:  $27.00 USD

The SY-X5 surprised me: what makes this model stand out is the fact that it can be powered by either a rechargeable slim battery pack (found in the DE32) or three standard AA batteries.  It also has a built-in MP3 player that, like the Degen DE32, uses a standard microSD card for media storage. Unlike the DE32, the SY-X5 has a bright red LED display that helps in navigating MP3 files. The SY-X5 also has surprisingly good audio from its built-in speaker, rivaling the much larger Tecsun R-2010D. The negative here? Though the SY-X5 has a fluid tuning mechanism, it is prone to drifting when trying to adjust the analog tuning needle to frequency.

IMG_0823The Kchibo KK9803 – Current retail:  $16.00 USD

When I first wrote this review, I didn’t even include the KK9803. Why? Because, frankly, it’s one of the worst performing radios I’ve ever owned, and I would strongly discourage you from even considering it. My primary criticism of this radio is that the tuning is barely functional:  the shortwave band segments are far too close to one another on the dial, hence the digital tuning steps are too narrowly-spaced to offer any sort of tuning accuracy whatsoever. Barely moving the tuning wheel, one may pass over even a strong station…undetectably. The only hint of the station’s existence may be an occasional quick blip or audio buzz. I must confess that the experience of band-scanning (tuning) this radio offers is the worst I’ve ever known in any radio. Don’t buy it. In our shootout, it’s bitten the dust before it even aims, because let’s face it:  this radio just can’t.

Audio comparisons

Click on each radio model to hear a short comparison audio clips. Note that I added an audio sample of the Tecsun PL-660 to the weak signal DX examples as a benchmark.

The Tecsun R-2010D (left) has the best audio from its large internal speaker, the Degen DE32, on the other hand, produces "tinny" audio via its speaker.

The Tecsun R-2010D (left) produces excellent audio from its large internal speaker. The Degen DE32 (right) produces “tinny” audio via its tiny built in speaker.

Local AM Comparison (1350 AM)
Degen DE321
Degen DE32
ShouYu SY-X5
Tecsun R-2010D

Weak Signal Shortwave Comparison (KBS 9,805 kHz)
Degen DE321
Degen DE32
ShouYu SY-X5
Tecsun R-2010D

Tecsun PL-660 (AM and Sync)

Strong Signal Shortwave Comparison (WINB 9,265 kHz)

Degen DE321
Degen DE32
ShouYu SY-X5
Tecsun R-2010D

The Winners

All of these radios share similar qualities.  After all, they’re brothers of a sort, built around the same family of DSP chips. If you’ve read the summaries above, then you won’t be disappointed by any of these that follow–especially at this modest price point. Still, I reach for different radios based on their strengths, and to help you choose, here’s a “best of” list:

Most versatile: ShouYu SY-X5

Best Audio: Tecsun R-2010D and ShouYu SY-X5

Best sensitivity: Tecsun R-2010D

Best value: Degen DE321

Best overall?

The ShouYu SY-X5

The ShouYu SY-X5

If I had to choose just one of these radios, it might just be the ShouYu SY-X5. It offers the most value and versatility for the performance. I think its audio is brilliant for a pocket radio, and I love the fact it has an LED display to help me navigate through the MP3 files loaded on my microSD card. However, as with any of these low-cost contenders, don’t expect to try any weak-signal DXing with the SY-X5.

By the way, if the Tecsun R-2010D simply had better selectivity and weak signal gain control, it would win this contest, hands down. In fact, I actually sent feedback to Tecsun engineering regarding the R-2010D selectivity shortcoming in the hope that they’ll fix this problem in future production runs.  You might do the same.

In conclusion, mechanically-tuned DSP portables may not pack DXer-grade performance, but they are priced so that everyone can afford to experiment. And for your buck, that’s pretty good radio bang!


This article was previously published in The Spectrum Monitor.


Resources

Click on the radio model to read full reviews of each radio on the SWLing Post–I’ve also provided links to eBay:

The new Tecsun R-2010D

TecsunR2010D

[UPDATE: Click here to read my full review of the R-2010D.]

I just ordered the Tecsun R-2010D–a SiLabs DSP-based shortwave radio with an analog dial and tuning mechanism–on eBay.

The Tecsun R-2010D is very similar to the Degen DE321, DE32 and the Kchibo KK-9803. I hold out hope though that the Tecsun will lead the pack of these small radios as Tecsun tends to do a better implementation of the SiLabs DSP chip.

Honestly, I had only recently decided that the R-2010 would never come to fruition.  I first was tipped off about it in 2009; then in 2011, a Tecsun representative told me that they were planning to re-design the R-2010. I suppose that’s how the R-2010D came about.

As soon as I receive this little radio, I’ll share my first impressions and a full review.

Click here to search for the Tecsun R-2010D on eBay.

Thanks for the tip, Paul!

SiLabs brings shortwave to car radios

Silicon Labs, a manufacture of DSP (Digital Signal Processing) chips that are in many of the shortwave radios we feature here on SWLing.com, is now taking their technology to car radios. They have announced the Si476x chip family which features AM/FM, longwave, shortwave (SW), NOAA weather band, FM RDS decoding and AM/FM HD Radio reception.

To my knowledge, this is the first time in years that shortwave has been strategically implemented in a car radio product.

Read their full press release below:

(Source: SiLabs Press release via Kim Elliott)

AUSTIN, Texas–(BUSINESS WIRE)–Silicon Laboratories Inc. (NASDAQ: SLAB), a leader in high-performance, analog-intensive, mixed-signal ICs, today introduced the industry’s most advanced automotive tuner IC family designed to deliver the highest RF performance coupled with advanced signal processing while reducing the cost and complexity of car radio systems. Offering superior price/performance for the global car radio market, the new Si476x tuner family provides a best-in-class multiband receiver solution for automotive infotainment head-units and AM/FM car radios from all classes of providers ranging from Tier 1 suppliers to aftermarket car radio makers.

According to J.D. Power and Associates, the global automotive market is expected to exceed 76 million light-vehicle unit shipments this year. The car radio technology deployed in these vehicles is evolving rapidly as innovations in communication technology proliferate in the automotive infotainment market. The basic car radio has been transformed into a sophisticated infotainment system that includes multiple tuners to deliver FM phase diversity reception, receive radio data system (RDS) data for info-navigation systems, support AM/FM HD Radio technology and provide detailed station quality metrics for living lists of broadcast content. These strenuous broadcast performance demands require advanced silicon innovations to enable a superior in-vehicle audio experience.

Silicon Labs developed the Si476x receiver family to address these major automotive industry trends. The Si476x receivers leverage Silicon Labs’ patented digital low-IF technology and combine most of the traditional external bill of materials into a highly integrated, single-chip CMOS solution. The receivers provide unprecedented flexibility, offering a modular architecture that supports scalable multi-tuner designs. The Si476x supports all worldwide broadcast radio bands including AM/FM, college FM, longwave (LW), shortwave (SW), NOAA weather band, unparalleled FM RDS decoding and AM/FM HD Radio reception. iBiquity Digital Corporation, the developer of HD Radio technology, has certified the Si476x family to provide AM/FM HD Radio tuner outputs and reception with compatible HD Radio demodulator ICs.

“The introduction of the Si476x tuner family represents a major new product offering from a world leader in RF products and a global player in the HD Radio market,” said Jeff Jury, chief operating officer of iBiquity. “Automakers are continuing to embrace HD Radio technology, with more than 20 automotive brands to date announcing the technology as a factory-installed infotainment feature. The Si476x family offers a compelling new solution for this market.”

The Si476x family represents the automotive industry’s first viable receiver alternative to enable developers to pair a best-in-class tuner IC with the optimal choice of audio digital signal processors (DSPs) to create highly cost-effective back-end audio processing designs. Silicon Labs has worked with leading silicon providers such as Cirrus Logic and Freescale Semiconductor to deliver comprehensive audio system solutions that break the expensive partitioning approach required by current car audio solutions.

“The combination of Cirrus Logic’s broad portfolio of audio ICs and Silicon Labs’ Si476x radio ICs provides automotive OEMs with a very powerful platform for building highly differentiated in-car entertainment products,” said Carl Alberty, director of marketing for audio products at Cirrus Logic. “By working closely with Silicon Labs, we have developed an optimized car radio platform that delivers best-in-class audio and RF technology, enabling our customers to build outstanding products.”

The superior linearity of the Si476x tuner’s integrated RF front-end, combined with a high-performance on-chip radio DSP and microcontroller, delivers outstanding RF dynamic range and immunity to multi-path fading. With this innovative architecture, the Si476x family raises the bar for such key features as selectivity, sensitivity, IMD3 break-in, desensitization, noise blanking, weak signal processing, dynamic channel bandwidth control and advanced dual-tuner FM phase diversity reception.

“The Si476x family not only delivers superior radio reception performance at the best system cost, it also provides unprecedented flexibility in audio processing solutions for car radio designs,” said Diwakar Vishakhadatta, general manager of Silicon Labs’ broadcast audio products. “With the introduction of the Si476x family, automotive developers are no longer locked into using more expensive bundled audio/radio solutions that may not address the audio processing requirements of their infotainment platforms.”

Pricing and Availability

Samples and production quantities of the Si476x car radio tuner ICs are available now in a compact 6 mm x 6 mm 40-pin QFN package. Pricing for automotive-grade Si476x tuner ICs begins at $11.62 (USD) in 10,000-unit quantities. The Si4763LNA-A-EVB and Si4767PD-A-EVB evaluation boards are available to automotive customers for $450 (USD).

The Si476x family, the latest addition to Silicon Labs’ portfolio of automotive-grade radio tuners, complements the company’s popular Si474x and Si475x tuner families, which target cost-sensitive entry- and mid-level radio designs. The Si476x family addresses premium-grade, performance-intensive automotive radio and head-unit requirements. For additional Si476x product information, please visit www.silabs.com/pr/automotive-tuner.

Silicon Laboratories Inc.

Silicon Laboratories is an industry leader in the innovation of high-performance, analog-intensive, mixed-signal ICs. Developed by a world-class engineering team with unsurpassed expertise in mixed-signal design, Silicon Labs’ diverse portfolio of patented semiconductor solutions offers customers significant advantages in performance, size and power consumption. For more information about Silicon Labs, please visit www.silabs.com.

Silicon Labs Si4734 DSP-based shortwave radios

The Silicon Labs Si4734/35

I have gone through our Shortwave Radio Index (SWRI) and tagged every portable radio that is based on the Silicon Labs Si4734 DSP chipset.

The Si4734 has been one of the biggest innovations to happen to portable receivers in recent years. When implemented well into a receiver design, the Si4734 can give a small portable exceptional selectivity and sensitivty through the power of DSP (Digital Signal Processing).

Simply click on this link to see a list of portable shortwave radios that are designed around the Silicon Labs Si4734:
http://swling.com/db/tag/si4734/

Silicon Labs ships one billionth DSP radio chip

Silicon Labs, the chip manufacturer behind some of the best portable shortwave radios in the market (including Tecsun and Grundig) has sold its one billionth DSP radio chip. Silicon Labs has been one of the best things to happen to the portable shortwave market this century. Their DSP chips lower the production cost of radios and enhance the performance with Digital Signal Processing.

I eagerly await the new Tecsun R-2010–an analog radio with the Silicon Labs’ Si483x DSP chip. Not only will it enhance the performance of this basic analog radio, but it should also decrease production costs by as much as 80%!

Here is the full SiLabs press release:

Industry’s First CMOS “Radio-on-a-Chip” ICs Widely Adopted in Leading Consumer Electronics and Automotive Designs

Reaching a major milestone in the broadcast audio market, Silicon Laboratories Inc [2]. (NASDAQ: SLAB), a leader in high-performance, analog-intensive, mixed-signal ICs, today announced that it has shipped its one billionth broadcast radio IC. Silicon Labs’ digital CMOS broadcast radios are widely used in handsets, portable media players (PMPs), personal navigation devices (PNDs), automotive infotainment systems, tabletop and bedside radios, portable radios, boom boxes and numerous other consumer electronics products.

Silicon Labs introduced the industry’s first single-chip FM receiver in 2005. As the industry’s smallest, highest performance and most integrated FM broadcast radio IC, the Si4700 [3] IC redefined how FM tuners were designed into consumer electronics products. At that time, traditional broadcast audio solutions were based on complex, costly analog architectures that required more than 30 discrete components. The highly integrated Si4700 revolutionized broadcast radio designs by offering exceptional, highly flexible performance, while simultaneously reducing component count by more than 90 percent and board space by more than 60 percent.

Over the past six years, Silicon Labs has rapidly expanded its broadcast audio portfolio [4] to more than 40 distinct products including FM radio receivers, FM radio transmitters/transceivers, AM/FM receivers, shortwave and weather band receivers, RDS data receivers and automotive radio receivers. These products are now the broadcast radio ICs of choice for many leading consumer electronics brands.

“Silicon Labs delivered the industry’s first monolithic all-CMOS FM receiver, providing breakthrough cost, size, integration and performance for broadcast receiver applications in handsets, navigation devices, media players and consumer electronics,” said Jag Bolaria, a senior analyst at The Linley Group. “The company has continued to drive market innovation in CMOS FM transmitters and multi-band AM/FM/SW and weather-band receivers, all widely adopted in the consumer electronics, portable and automotive markets.”

Silicon Labs’ broadcast radio ICs leverage the company’s patented low-IF digital architecture, which enables the highest level of selectivity and sensitivity performance for radios, resulting in reduced interference and superior reception. In addition, Silicon Labs broadcast receivers incorporate advanced audio processing technology that delivers sound quality that is unmatched by other competing radio receiver ICs.

“Silicon Labs thrives on pioneering new ways to solve difficult system design challenges with mixed-signal technology,” said Diwakar Vishakhadatta, general manager of Silicon Labs’ broadcast audio products. “Our single-chip FM, AM/FM receiver and transceiver families are a case in point. These products have helped our customers reduce the cost and complexity of their designs while enabling more features and functionality to help them differentiate their products in the marketplace. We continue to invest and innovate around our low-IF digital architecture to remain a strategic supplier of broadcast radio technology to the industry.”

Silicon Labs has approximately 100 issued and pending worldwide patent applications in audio technologies for its AM and FM related products.

For additional information about Silicon Labs’ broadcast audio products, please visit www.silabs.com/pr/broadcast.