Category Archives: Mediumwave

Dan compares and reviews the Tecsun S-8800 portable AM/FM/shortwave receiver

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Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post and review:

Tecsun’s S-8800:  Is This All The Radio You Will Ever Need?

These days, we who still derive enjoyment from listening to shortwave broadcasts, be they larger international broadcasters or smaller stations that remain on the air against all odds in the Internet age, also enjoy using the many types of radio receivers that enable this activity.

One of the cruel ironies is that today’s technological advances have made possible the kind of worldband radios (the term that first came into wide use way back in the 1980’s) that years ago we could only dream of, be they full communications receivers or portable receivers.

Having begun my own DXing/SWL career in the late 1960’s, and pretty much maintained my hobby activities over the decades, I have used pretty much every receiver that ever existed, from tube radios to today’s latest DSP wonders.

I have a soft spot for classics from SONY — my list of portables today includes the fantastic SONY ICF-SW77, SW-07, SW-55s and SW-100.  Panasonic is represented in my portable collection by the wonderful RF-B65.

Only in recent years did I decide to test the main higher end portable offerings from Tecsun:  the PL-660/680, and PL-880. What I discovered, as have most people who own the Tecsuns, and similar receivers such as the XHDATA D-808, are the wonders of DSP chips and the great flexibility they provide, such as multiple selectivity options, along with excellent sensitivity.

Though it’s been on the market for going on three years now, one of the receivers I had not been able to test was the Tecsun S-8800.  There are quite a few reviews already online. Some go into extensive detail in describing the plus and minus points of the radio.

With so many people having already assessed the radio — and most of them in fairly glowing terms — I won’t repeat a long list of technical specs, as you can find those in other reviews, and on the site of Hong Kong-based Anon-co, which is probably the main seller of the S-8800.

Headline

The S-8800 is arguably the best multi band radio portable among portable category offerings on the market today.  It combines superior audio delivered from its superb front-firing speaker, with equally superb sensitivity (triple conversion), and multiple selectivity options, with an amazingly professionally-executed remote control.

I used the S-8800 in a number of physical locations, from public parks where I hoped to avoid high noise levels, to my back yard where noise levels are, unfortunately, quite high.  I have compared the S-8800 to a number of portables in my collection, including: SONY ICF-2010, SW-77, SW-55, along with Tecsun’s 660 and 880, Grundig SAT-500.

Audio

Hands down, the S-8800 wins the audio competition when compared to pretty much every other radio.  Where the competition gets tight is with receivers such as the classic Grundig Satellit 500, and Tecsun’s PL-880.

Sensitivity

This is a TRIPLE conversion radio.  As everyone knows by now, Tecsun did not merely adopt the cabinet of the old Eton S350 but basically stuffed a hot rod racer into the cabinet of what was previously a mediocre radio at best.

Selectivity

Widely used in a number of radios these days, the S-8800 uses a DSP chip that is seen in a number of other receivers.  The best description I have seen so far is in the review by Jay Allen who notes that Tecsun “decided to utilize a combination of DSP (Digital Signal Processing) circuits along with traditional analog circuits . . .most of the AM/SW circuitry is PLL/analog along with the 1st and 2nd IF’s, while the 3rd IF is DSP.”  It appears that after a bit of a rocky period in the beginning when initial units suffered from images and birdies, Tecsun got it right.

Ergonomics

Much has been said about the fact that Tecsun decided not to include a keypad on the radio itself.  I too was skeptical. We have all become accustomed to keypads as standard equipment on portables.

Personally, I do a lot of my listening on the beach during vacations, and am used to being able to hold and operate the radio in such situations, so the thought of having to carry a remote control seemed uncomfortable at best.

However, the reality is that it’s still possible to navigate the shortwave, AM, and FM bands easily even without the remote — call me old fashioned, but I am from a group of older listeners who have most frequencies memorized anyway, so I know where I want to go to hear certain stations.

Tecsun hit it out the ballpark with the remote supplied with the S-8800.  It looks like something you would find with high end stereo equipment and clearly much thought went into making sure it can control every aspect of the receiver, from SW band slewing to selectivity, volume, readout — everything except BASS and TREBLE control, Timer/Alarm, and master volume (i.e. as other reviewers note, you have to set the on-radio master volume to a high enough level first, then use the remote to vary).

Power

The radio requires two 18650 lithium (Li-ion) rechargeable batteries, with individual indicator LEDS inside the battery compartment.  This choice is perhaps one of the most controversial aspects of the 8800. Among other things, 18650s usually receive more attention from airport security personnel if one is taking the radio on a trip — this is something everyone should keep in mind.  Any radio being transported on a flight these days is going to be subjected to added scrutiny, simply because almost no one uses radios anymore.

As for the power needs of the receiver, the 18650s seem to do a good job and last quite a long time, even days.  Included in the box is one of those white USB charger blocks — quite small and convenient. I usually travel with separate 18650 chargers, the kind used with high end flashlights, so having spare sets of charged batteries is not a problem.  But if both 18650’s in the Tecsun are drained, the radio definitely needs to re-charge to a minimum level required for operation.

As I write this, I plugged the S-8800 into a wall outlet (a blue LED indicator on front indicates charging mode) and I was unable to use the radio as the battery level had completely zeroed out.  Also keep in mind that the USB charging brick throws off EMI to other radios in the vicinity, and makes it impossible to use the S-8800 itself — there is just too much interference from the charging process to the radio’s receiving circuitry.

Comparisons

As mentioned, I compared the S-8800 with a number of other portables in my collection.  Each of these other radios, including the classics from SONY such as the SW-55 or SW77 have their strengths.  For example, the SW77 has the best implemented synchronous reception of any portable since the ICF-2010 along with superb sensitivity.  However, even the large speaker on the SW-77 was unable to compete with the S-8800. Only radios such as the older Grundig SAT 500/700 had the advantage when compared to the S-8800’s speaker, with the Tecsun PL-8800 close behind.

Receiving Comparisons

I decided to take the S-8800 out to my back yard for a receiving comparison with the receiver I consider to be among the top five best in what I call the small portable category (which is above the mini-portable category in which we find the SONY SW-100 and SW-07 and similar size radios).

In intensive use over the years, I have concluded that the Panasonic RF-B65 is probably among the hottest small portables.  With its famous amplified whip antenna, the 65 time after time succeeds in allowing me to hear stations that other portables struggle with (see this 3 radio comparison I posted a few years ago in which the B65 outguns the Sangean 909X and SONY SW-07).

Rather than produce several separate videos, I have combined one listening session comparing the S-8800 with the RF-B65.  It’s a bit long, so my apologies, but gives you an idea of how these two fine portables did going head to head.

Click here to view on YouTube.

Leaving aside the obvious superiority of the Tecsun where audio is concerned, the S-8800 competes well with the Pan RF-B65, often superior to the smaller radio, but sometimes inferior in one respect.

While there was nothing the S-8800 could hear that the Panasonic could not, signals seem to jump out of the S-8800 in a way that they did not with the smaller radio. However, there appeared to be an interesting difference when it came to the ability of each radio to deal with interfering stations 5 kHz above or below.

As shown in the video, the Panasonic was able to distinguish more clearly between a station on 9,650 kHz (Guinea) and a station 5 kHz above (in this case, Algeria via France, using 9,655 kHz) than the Tecsun, which seemed to struggle.  Indeed, at one point I was forced to attempt ECSS (Exalted Carrier SSB) mode to separate the two stations, whereas on the Panasonic, being the older and simpler radio design was an advantage in that the RF-B65 was actually able to more clearly separate the two stations by “de-tuning” from the center frequency.

One huge advantage of the S-8800 by the way is that there is a hidden software change that enables one to adjust SSB zero beat to zero or near zero.  This means that in theory using LSB/USB to improve reception is possible, though keep in mind that there may be some variation from unit to unit. So far, after performing the so-called ‘secret’ fix (among a list of tweaks discovered so far) my particular S-8800 appears to be able to zero beat LSB/USB with little or no variation between the side bands, pretty much up and down the SW bands.

Conclusions

For me, the S-8800 has turned out to be the biggest surprise of the last several years.  Coming seemingly out of nowhere, packaged in the cabinet of a receiver that was seen as mediocre at best, we have a triple conversion beauty (it seems to weigh almost nothing by the way) that provides pretty much every tool required these days to tackle what is left of shortwave broadcast reception.  It has superior audio, unless one compares to older Grundig and similar sets.

Drawbacks are quite few to be honest.  A case can definitely be made that using 18650 batteries was a poor choice by Tecsun.  This means, for example, that if you’re out on the beach or elsewhere for many hours, the only way to charge up the radio would be to use a separate phone battery charger rather than simply be able to slip in regular alkalines.  But then, I carry separate battery charge units already for my phone.

The big criticism that synchronous reception could have been included is also valid.  The same was said about the SONY ICF-SW55 — with synchronous reception, and a bit more careful design of the tuning circuit, that radio could have been a heavier hitter, a mini-ICF 2010, something the much more expensive SW-77 was designed to improve upon.

However, so far radios utilizing DSP chips have struggled when it comes to synchronous reception capability.  Indeed, the feature has ended up being discovered only as one of a number of ‘secret’ features. Only the PL-660 has a decent synchronous feature, but that radio is hobbled by limited selectivity options, while sync on the PL-880 is pretty much useless.

Finally, I have to say thank you to Tecsun for doing everything possible to avoid the dreaded ‘MUTING’ problem that has been seen on so many small portables.

As I found to my disappointment when using even the much-praised Eton Grundig Satellit, and even the C Crane Skywave SSB, this problem can be a killer for those of us who consider it absolutely critical to be able to hear EVERYTHING on and between frequencies.

So, the big question — would I recommend the S-8800?  As with almost everything, the answer to that is, it depends on what kind of a listener you are, and expectations.

From a performance perspective, if you are like me, a die-hard DX’er at heart who gets a kick out of searching for the last Peruvians on the air, the S-8800 should be more than sufficient.  If you’re both a die-hard DX’er and enjoy FM and AM, the 8800 should also be a perfect selection, since it’s been reviewed quite well in terms of medium wave and FM capability.

A personal note — for me, part of the fun of shortwave portables has been their ‘cool factor’.  I’m just one of those who likes to carry around complicated looking radios with lots of buttons. The SONY 2010, SW-55, SW-77s, older Grundigs all fit the bill.

I never thought the S-8800 or radios similar to it in appearance would.  So, for me it’s going to require a bit of a change, since the S-8800 looks like, well . . . it looks like a ‘toy radio’!

But it’s one hell of a toy-looking radio.  It’s a triple conversion monster packed in the frame of something that, at one point in the past, you might have considered getting for your kids (if they even knew or know what a radio is!).

As many of us are at this point in our lives, I am also thinking ahead — to the day when my numerous premium Watkins Johnson and JRC radios, and a few boatanchors hanging around, will have to go because of downsizing.

When I’m 65, as the Beatles song goes — or more likely 85 or 90 — what will I be able to fit on a bedside dresser and use easily to tune in whatever is left on shortwave (if anything)?

The answer to that question is a radio that’s small enough and enough of a performer, preferably with a well-designed remote, to bring in anything that’s still on HF, MW, and FM.  With those needs in mind, the answer is already here, in the Tecsun S-8800.

[I want to express sincere thanks to Anna at Anon-co who responded quickly when I proposed a review of the S-8800 and supplied the receiver on which this article is based.  Anna was patient as my original plan to have a review in by September was delayed by unavoidable personal matters. Thanks also to Tom Witherspoon for getting the review up so quickly].

Click here to check out the Tecsun S-8800 at Anon-Co’s website and here via the Anon-Co eBay store.

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WSJ: AM radio and electric cars don’t mix

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(Source: Wall Street Journal via Bob LaRose W6ACU

Cars and AM radio go back a long way, but there’s a rough road ahead for the old travel buddies.

The same types of electric-powered motors that propel Teslas past 150 mph and the Chevy Bolt as far as 238 miles on a charge, are a total buzz kill for AM reception. Instead of sports, oldies or news, it’s more like all-static, all-the-time radio.

As auto makers race headlong into an electrified future, AM radios are getting kicked to the curb, joining cassette decks, eight-track players and ashtrays.

Daniel Rich is a fan of both San Francisco’s KNBR-AM 680 and his Chevy Bolt. That means his commute isn’t as easygoing as it used to be. “All my other cars over the years could receive that station just fine, despite the distance,” the 58-year-old eye surgeon said. “Not the Bolt.”

A General Motors Co. spokeswoman said GM was aware of the issue in the Bolt and has “taken steps,” but declined to say exactly what they are.[…]

Click here to read the full article at the Wall Street Journal.

Review Update: CCRadio-EP Pro’s major improvements!

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In April, I posted a review of C. Crane’s latest iteration of the much-loved EP series: the C. Crane CCRadio-EP Pro.

Although the new Pro model had the makings of a great, simple DXer-grade receiver, the first production run was plagued with issues that, in the end, prevented me from recommending it to radio enthusiasts and DXers. Frankly speaking, I was quite disappointed.

I evaluated the original CCRadio-EP Pro over the course of several weeks, documenting my findings in detail and sharing them with C. Crane both during the evaluation period and in my full review.

But to C. Crane’s credit––being a company of integrity––they responded to each point of criticism, promising to address the issues in the receiver’s second production run.

Enter the second production run…

About six weeks ago, I took delivery of a second-production-run CCRadio-EP Pro.

The second-run units have actually been shipping for a few months now, but due to nearly two months of travel and a hectic schedule following, my evaluation took longer than I had hoped. And if you’ve been following the SWLing Post for long, you’ll have noticed that I never rush a radio evaluation…and for good reason. Post readers are placing their trust in my review, so I must feel confident it’s as accurate––and as transparent––as I can make it.

Speaking of transparency, by the way, please note that C. Crane provided the initial and second production evaluation units at no cost to me.

What follows is a review of the second-run CCRadio-EP Pro. I would encourage you to read my original review before proceeding, because I am (only) addressing all of the negatives I listed from the previous review.  However, for your convenience, I’ve included quotes from the original here.

In a nutshell?  C. Crane listened to my list of concerns, and I’m very pleased!

Muting between frequencies?

 

From my first production run review:

[M]echanically-tuned DSP radios, like the new CCRadio-EP Pro, may look like analog sets, but inside, they’re entirely digital. And one drawback to all of the mechanically-tuned DSP radios I’ve tested so far is a tendency to mute between frequencies. With each 10 kHz frequency step, you’ll hear a short audio mute. If you tune across the dial quickly, audio mutes until you land on a frequency.

I’m pleased to report that C. Crane has significantly decreased the amount of muting between frequencies. Indeed, even on the AM band (which was most affected in the first production run), muting no longer distracts me from the experience of band scanning.

Unlike an analog receiver, if you tune quickly across the band, the EP Pro essentially mutes audio completely.  This is common with analog-tuned DSP receivers. This is still the case with the second production run unit, but this does not concern me, as I rarely move quickly across the bands while hunting weak signals.

Imaging?

From my first production run review:

Crane actually includes a note about weak images which you might find below and/or above your target signal. Weak images are an unfortunate reality of the CCRadio-EP Pro; they’re prevalent on both AM and FM.

On the initial production receiver, here’s how you might experience the images by way of example: let’s say you’re tuning to a strong local AM station on 630 kHz, noting that the EP Pro has 10 kHz tuning increments. As you tune to 630 kHz, you’ll hear the station on 620 kHz, though it won’t be as strong as it is on 630 kHz. Then if you tune to 640 kHz, you’ll likely hear a weaker image of the station there, as well. In my experience, images are present on both sides of the target station if the station is strong. If it’s a weak station, you might only hear it, say, 10 kHz lower but not above (or vise versa).

As you might imagine, this poses a problem for the weak signal AM broadcast band DXer.

I’m pleased to report that C. Crane has eliminated the false peaks around signals. This was a major negative from the original review. Now, as you tune across the bands, it feels more fluid, and when you hear a station you can be confident you’re actually on frequency as it seamlessly “locks” into place.

Well done, C. Crane!

Inaccurate dial?

At the top end of the band, the EP Pro tuned to 1600 kHz

From the first production run review:

I’ve also discovered that, on my unit, the top half of the AM dial is inaccurate. I estimate that the slide rule dial is off by about 40-50 kHz at the top end of the band. It’s much more accurate below 1,200 kHz, however.

I’m pleased to report that the dial on this second production run unit is now as accurate as any analog radio. I tested frequency accuracy across the entire AM/FM bands, and can reliably find stations. Another major negative C. Crane fixed!

Audio “pop” with power on?

From the first production run review:

[A]ny time you turn on the CCRadio-EP Pro, you’ll hear an audio “pop.” This is happening when power is applied to the audio amplifier. The pop is not soft, but fairly audible, and is present even if you turn the volume down all the way. The audio pop is prevalent via both the internal speaker and when using headphones. Fortunately, it’s much less pronounced via headphones.  While not a major negative, I find it a bit annoying, and don’t doubt that other listeners will, too.

C. Crane has managed to minimize–not eliminate–the audio pop. It’s much improved over the first production run unit. I think I would still make note of it in the “cons” section if this were my first review of the radio, but it’s truly a very minor complaint at this point.

AM frequency steps limited to 10 kHz?

Note the new 9/10 kHz switch below the AM Antenna switch

From the first production run review:

My initial production run EP Pro is limited to 10 kHz frequency steps. This radio is primarily marketed to North America where 10 kHz increments are standard. Of course, if you’re trying to use the EP Pro to snag Transatlantic or Transpacific DX, you’ll miss the ability to tune between those broad 10 kHz steps. But, again, due to the imaging mention above, I think the CCRadio-EP Pro is simply not suited for DXing.

I’m pleased to report that C. Crane has added a switch that allows the listener to toggle between 9 and 10 kHz AM steps! This was an essential upgrade for those of us planning to use the CCRadio-EP Pro outside North America, or for those of us attempting to chase signals from across the ocean. Very nice, C. Crane!

Conclusion

To their credit, C. Crane has addressed all of the major negatives I listed in my review of the first production run units.

And as a result, I can now recommend the CCRadio-EP Pro with confidence.

I should add that during the course of this evaluation, I spent some valuable time on the mediumwave/AM broadcast band and have been very impressed with the EP Pro’s sensitivity and selectivity. The AGC can cope with weak signals quite well; I noted none of the soft muting which plagues a number of other DSP receivers. And the Twin Coil Ferrite tuning can substantially improve reception of weak signals––don’t ignore that control on the right side of the radio! Very useful.

With renewed confidence in the EP Pro, when I have time this fall or winter, I plan to take it to the field and pit it against my beloved (and recently re-capped!) Panasonic RF-2200. I’m beginning to think it might be a real competitor. We will see.

I would encourage you to also check out Guy Atkins’ recent evaluation of the EP Pro. I’m in agreement with his assessment, which leads me to believe quality control is also consistent in the production run. Good news all around. I’m very happy that C. Crane fixed early production run issues with both the CCRadio-EP Pro and the CC Skywave SSB. Well done!  I’m so glad C. Crane paid attention.

You can purchase the CCRadio-EP Pro from the following retailers:

How to identify a second (or later) production run unit

I know I’m going to receive emails and comments about how to tell if one has a first or second production EP Pro. The answer is very simple…

If your unit has a 9/10 kHz step switch on the back (see photo directly above) then you have a second production run unit or later.  

While the first production run EP Pro will please most average radio listeners, I couldn’t recommend it for the level of radio enthusiast and DXer who spends time reading reviews on the SWLing Post.

If you plan to purchase the CCRadio-EP Pro this year, I would encourage you to check with the retailer to make sure you’re getting a unit from the second production run or later.

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SDR Primer Part 3: From High-End SDR Receivers to SDR Transceivers

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

Welcome back to the world of SDRs once again

In September we began of our three-part Primer on Software-Defined Radios (SDRs). Part One (September) focused on the nomenclature and components of a functioning SDR system; Part Two (October) took a look at some affordable SDR station options that will propel you into the world of SDRs for less than $200 US. This month, in Part Three––our final installation––we’ll dive a little deeper into the SDR rabbit hole, and investigate higher-end SDRs as well as ham radio transceivers with embedded SDRs.

Investing in SDR hardware

As we mentioned in Part 2 of our primer, gaining entry into the world of SDRs can be quite affordable. With merely $200 or less, you can fully explore the radio spectrum with an SDR that has truly excellent performance characteristics.

So, why would you pay more?

Let’s consider this.  If, say, you happen to live in an RF-dense environment, such as a busy city, if you live near strong broadcaster(s), and/or if you’re a DXer who’s seeking benchmark performance, then you might wish to devote a little more of your cash to your SDR hardware.

When you pay more for an SDR, the additional cost is typically going toward the hardware rather than the software. Indeed, my favorite SDR (software) applications are absolutely free, and pair with a number of benchmark SDRs. But good hardware is vital to performance. The lineup of SDRs––that is, the receiver hardware––discussed below typically has better filtering, preselectors, shielding, and receiver architecture focused on HF performance. They also tend to offer a more robust front end, lower noise floor, and better dynamic range. All of this, of course, results in better performance overall. Some of these SDRs also offer unique specialty features, like built-in web servers.

The following SDRs are carefully hand selected, and in my view, represent a balance between price and performance. And again, this is by no means a comprehensive list; it’s simply a selection of what you’ll find currently available on the SDR market.

So, without further ado, we’ll begin our discussion with “black box” SDRs, then move on to  SDR transceivers and transceivers with embedded SDRs.

SDRplay RSPduo

The SDRplay RSPduo

In May of this year (2018), the UK-based SDR designer and manufacturer SDRplay released their latest receiver: the SDRplay RSPduo.

What sets this little black box apart from the competition is just what its name implies:  the duo is a dual tuner SDR.  In other words, it’s two independent SDRs rolled into one.

Being the price leader in the world of SDRs, SDRplay retails the RSPduo for $279.95. And, I must add, it’s a true bargain for a feature-packed 14-bit high-performance device.

The RSPduo’s tuners can operate individually, anywhere between 1kHz and 2GHz, with up to 10MHz of working bandwidth. You could also set up the RSPduo so that both tuners can operate simultaneously, again between 1kHz and 2GHz, with up to 2MHz of bandwidth per tuner. The RSPduo has a high-stability reference along with external clocking features which makes this SDR an affordable option for industrial, scientific, as well as educational applications. It’s housed in a quality steel enclosure.

SDRplay’s development team is already working on new features such as true diversity reception, which will be included as a free upgrade to their popular SDRuno proprietary application.

To be clear, there is no other sub-$300 SDR on the market that currently has true dual-tuner functionality. Thus, the RSPduo is a good value, in my opinion––and an inexpensive upgrade to a proper dual-receiver SDR––so if this is something you’d like to add to your shack, go ahead!  Bite the bullet, and acquire an RSPduo. Likely you won’t regret it.

Check out the RSPduo via:

KiwiSDR

Photo by Mark Fahey

Like the RSPduo, the KiwiSDR has a unique feature that makes it stand out among the other receivers mentioned here: it is designed to be fully controlled via a web-browser-based SDR application. Not only can you use your KiwiSDR locally, but you can share it with the world via the KiwiSDR network. You can configure the KiwiSDR to allow up to eight simultaneous guest users, assuming only that you have access to the modest amount of Internet bandwidth this requires.

The KiwiSDR ships as a simple modular kit, and requires no special tools to assemble: the SDR is a custom circuit board (known as a “cape”) that you connect to BeagleBone Green or BeagleBone Black mini computer. (Click here to learn more about the BeagleBone).

The KiwiSDR is available in two versions: the SDR cape, alone, and a more complete version which includes the SDR cape, BeagleBone computer, enclosure, and GPS antenna. Both versions include all SDR software loaded on a micro-SD card.

Although the KiwiSDR might sound like an experimenter’s receiver since it requires a degree of assembly and configuration––at least, a bit more so than the other units I review here––it’s actually fairly simple to assemble, install, and put on the air. In fact, the only challenge that you might face is that of setting up your router for global access to your KiwiSDR. It does require either a static IP address or (more commonly) an IP address forwarding service. Check out the support documentation in advance to make sure your Internet connection will work.

The KiwiSDR covers from 10 kHz to 30 MHz, thus is not a wideband receiver like the SDRduo. Like the SDRs that follow, it focuses its performance on HF and lower bands.

I find it incredible that for just $299 US, you can purchase the full KiwiSDR kit––one that includes everything you need to put your SDR on the air and online. Because of this, I believe the KiwiSDR has become the dominant web SDR platform currently on the market. Perhaps this remarkable fact overshadows the fact that the KiwiSDR is also a superb performer, touting a brilliant dynamic range as well as overall excellent sensitivity and selectivity.

As my friend and fellow radio listener Mark Fahey, an early adopter of the KiwiSDR, is quick to point out, the KIwiSDR is unique in that it doesn’t connect to a PC or other computer to operate. It’s a stand-alone:  just connect an antenna, DC supply, and network cable, then you’re ready to go. All of the “work” is delivered by the piggyback BeagleBone CPU.

What’s not to love? While the web-based SDR application is full-featured, it does lack spectrum recording and some other advanced controls. This is due to the relatively modest processing power of the onboard CPU. That said, The KiwiSDR application does contain features/functionality via extensions that are fairly impressive.

Additionally, when updates are rolled out for the KiwiSDr application, these take effect globally. Only recently, for example, audio recording and amazing TDoA (Time Distance of Arrival) functionality were added.

Oh, and one more thing before we move on: the KiwiSDR is the only SDR I know that is exclusively controlled by a web-based SDR application for both the online guest and the local user/owner. There is no separate downloadable application.  Thus, whether you’re using your own local KiwiSDR or an online SDR, the user experience is exactly the same. It’s seamless and user-friendly…just as it should be.

Want to try the KiwiSDR before purchasing? Easy! You can browse and select any one of two hundred KiwiSDRs online on SDR.hu.

Check out the KiwiSDR via:

ELAD FDM-S2/FDM-S3

Italian-based SDR manufacturer, ELAD, has built a solid reputation over the years for truly pushing the SDR performance envelope in the $500-$1000 market.

I have owned their Elad FDM-S2 for four years now (check out my full review in the November 2014 issue of The Spectrum Monitor). The FDM-S2 continues to impress and to hold its own among more recent competitors––a true indication of excellent engineering and hardware.

The FDM-S2’s frequency coverage is 9 kHz-52 MHz, 74-108 MHz, and 135-160 MHz. I should note here that besides being a great HF and mediumwave performer, the FDM-S2 is an FM DXer’s choice receiver; FM performance on this rig is just superb.

ELAD supports all of their SDRs with their own proprietary application which, of course, is designed to take full advantage of the SDR’s available performance. The ELAD application is feature-packed and even includes built-in DRM decoding. Interestingly, it will allow the FDM-S2 to be used as two completely independent tuners in “double DDC mode”––the working bandwidth of each tuner, in this case, is 384 kHz, and each can be placed within one of the FDM-S2’s input ranges.

In truth, I like pairing my FDM-S2 with the excellent (and free) SDR Console SDR application; I prefer its user interface and recording functionality over the ELAD application.

If you live in an RF-dense area, you might consider one of ELADs external pre-selection filter systems to keep the FDM-S2 from overloading in the presence of very strong signals.

The FDM-S2 is currently priced at $529 US.

Photo of the new ELAD FDM-S3 from the 2018 Hamvention

Note that ELAD will soon be releasing the newest addition to their product line: the FDM-S3. I know very little about the FDM-S3, but I do know ELAD is promising groundbreaking performance and dynamic range, setting a new benchmark for the $1000 price bracket. We do know the FDM-S3’s processing bandwidth is an impressive 24.576 MHz––wide enough to include the entire FM broadcast band!

I’m not sure if FM DXers will be able to take advantage of spectrum recording at a 24 MHz bandwidth, because I suspect it could push 24GB of data per minute. The FDM-S3 may well keep up, but I’m not sure the typical computer hardware can handle that kind of data transfer…it may be likened to, in radio terms, drinking from the proverbial fire hose!

However: ELAD will be sending me a loaner FDM-S3 to review in the coming months, so stay tuned for more on this DXer’s dream rig!

The current FDM-S3 price, by the way, is 949.90 EUR.

WinRadio Excalibur

The WinRadio Excalibur

My first foray into the world of benchmark SDRs was made with the Australian-made WinRadio WR-G31DDC Excalibur. And although this SDR has been on the market for the better part of a decade, it still outperforms many of its competitors.The Excalibur’s frequency range is 9 kHz to 49.995 MHz, providing absolutely stellar performance across the spectrum.

It’s a favorite SDR in my radio shack, despite the fact that it can only be fully controlled by WinRadio’s own proprietary SDR application (at least, I know of no other compatible applications). On the plus side, the WinRadio application is one of my favorites.

The application’s file size is extremely compact––only a 9MB download. The user interface is logical, ergonomic, and responsive. Other than SDR Console, it has some of the best recording functionality available today.

I’ve logged more airtime with the Excalibur than with any other SDR I own, mainly because of its superb overall performance, responsive application, and recording functionality. I use the Excalibur as a benchmark for receiver evaluations and find that very few can match its solid performance.

The WinRadio Excalibur can be purchased through a number of distributors worldwide for about $950.

Enablia TitanSDR Pro

The Enablia Titan SDR Pro is an outlier product in our SDR Primer series, in that it retails in excess of $2,000. However, it’s the highest performing SDR I’ve ever tested. Serious weak-signal DXers will likely be quite pleased with this rig.

And speaking as a radio archivist, the Titan has the most powerful set of audio and spectrum recording features I’ve used, to date. Selectable spectrum recordings can be made from within the wide working bandwidth, and it can run up to four fully-independent SDR receivers, simultaneously.

The Titan comes with 16 frequency preselectors onboard, and a 9 kHz to 32 MHz frequency coverage. Its front end is simply bullet-proof, and thus could be operated in a demanding RF environment.

The TitanSDR ships with a brilliant proprietary application. It’s designed to make managing the Titan’s multiple virtual receivers and four independent SDR receivers as straightforward (and easy!) as possible. As I said in my review, Enablia engineers quite successfully accomplished this. The only downside is that only the TitanSDR application can run only the TitanSDR; no other third-party apps work with it. In addition, when making spectrum recordings, the file format is unique and the header information is actually stored in a separate file. This means when you are transferring a set of spectrum recordings, the header file must also be accounted for.

Of course, there is the daunting price tag of the TitanSDR, which makes it clear that this was a receiver designed for government and commercial use, in particular, for signal intelligence.  Thus it’s likely no surprise that the basic version of the TitanSDR retails for 1380 EUR, the TitanSDR Pro for an even heftier 1970 EUR.

To be fair, there are not many readers who would consider the TitanSDR Pro, but I thought it worth mentioning as it demonstrates a clear case of hardware becoming an innovation’s primary focus.

Enablia’s website is quite basic, so I would recommend you contact them directly to ask for a price quote if you’re interested in one of their TitanSDRs.

Other SDRs

The SDRs above represent merely a small slice of SDR market availability. There are several other notable manufacturers and SDRs worth considering, thus worth noting.

The Bonito Radiojet 1309 Plus

Germany-based Bonito manufactures a number of SDRs, antennas and components that are highly regarded among DXers. Bonito’s “hybrid” SDRs pack a lot of performance yet require very little in terms of computer resources.  Their latest SDR, the Bonito RadioJet 1309 Plus covers 0.02 MHz to 1600 MHz with a spectrum display that can be widened to 3.2 MHz. I have not personally evaluated the RadioJet 1309 Plus, but I did review an early version of the RadioJet (the 1102S) that lacked the additional IQ-receiver of the 1309. I found it an impressively sensitive and selective receiver with excellent audio characteristics. Click here to read that review.

The RFspace Cloud-IQ

RF Space has been manufacturing SDRs longer than many other manufacturers, and the company offers a number of products, including the SDR-IQ, the NetSDR+, the Cloud-IQ, and––soon to come––the CloudSDR.

In Part 2 of our primer, we mentioned the AirSpy HF+ which packs impressive HF performance. Airspy also manufactures the Airspy R2 and Spyverter R2–this $218 US combination produces a compact SDR package with excellent dynamic range and superb frequency stability.

I’m also fond of the classic Microtelecom Perseus SDR, which I’ve seen sold used for approximately $700 US. WinRadio, too, offers higher-end SDRs with a wider frequency range and working bandwidth than the Excalibur––so if your budget allows, you might consider these.

Regardless, keep in mind that if you want to use your monetary resources efficiently, there is no need to splurge for higher-end SDRs unless your use and application demands increased performance. Before you pull the trigger to buy such a rig, I would simply take into consideration the unit’s frequency range, working bandwidth, and performance characteristics, as well as taking the time to read plenty of user reviews. This increases the odds that you’ll get just what you want.

SDR Transceivers

So far, I’ve only mentioned SDR receivers in this primer, but there is a healthy selection of “black box” type SDR transceivers on the market, as well. By “black box,” I mean the transceiver itself (all of the hardware) housed in a box––with, of course, the relevant ports for antennas, data, power, mics, CW keys, and a number of peripherals. These SDRs almost always require a computer for operation, although lately manufacturers are beginning to offer optional touch-screen front panels which can bypass the need for external computer operation.

Unlike the world of tabletop radios, where it might be less expensive to invest in a general coverage transceiver rather than a dedicated receiver, SDR transceivers almost always cost more than an equivalent SDR receiver.

Also note that SDR transceiver applications do not always include audio and spectrum recording functions.  In addition, their working bandwidth might be more narrow that other receive-only SDRs, although they may offer more virtual receivers and spectrum “slices.”

Finally, SDR transceiver applications tend to be proprietary; when you purchase the transceiver, you’re also likely receiving the only SDR application that will interface with it. Hypothetically, if you purchase an SDR transceiver and the company that produced it goes under, you might have issues when the application is no longer updated with operating system upgrades and iterations.  The lesson here is that I believe you should try to stick with the healthiest companies and those with solid, large user bases. This increases the likelihood that the application will be supported in the future.

Low-cost, low power SDRs for the experimenter

We’ll start with the least expensive SDR transceivers designed with the experimenter in mind, that can, with a little adaptation, also be employed by ham radio operators as very low-power transceivers.

The HackRF One ($299) by Great Scott Gadgets is an excellent SDR. It has an incredibly wide frequency range (1 MHz to 6 GHz), and can transmit anywhere from 3 mW to 30 mW depending on the frequency. That’s flea power, true, but if your goal is to experiment in your local surroundings, it’s typically more than enough output. The HackRF is open-source and sports a large user community that have employed it in dozens of applications. The HackRF was one of the first SDRs to really give experimenters a full tool set to manipulate the world of wireless.

Check out the HackRF One via:

The LimeSDR board

The LimeSDR ($299) is another crowd-funded project that has been incredibly popular.  Like the HackRF, it is a low-cost, open-source SDR platform that can be used to support just about any type of wireless communication standard. What makes the LimeSDR unique is that it is integrated with a Snappy Ubuntu Core, which means users can simply install applications from an app store to increase functionality. As LimeSDR states, their platform “gives students, inventors, and developers an intelligent and flexible device for manipulating wireless signals, so they can learn, experiment, and develop with freedom from limited functionality and expensive proprietary devices.

Again, only consider the HackRF of LimeSDR if your main goal is to experiment with the world of wireless. If you’re looking for a full-featured SDR transceiver intended for ham radio, read on.

Ham Radio SDR Transceivers

The Flex Radio booth at the 2018 Hamvention.

Without a doubt, the dominant name in the world of US ham radio transceivers is Texas-based Flex Radio.  Flex has been around since the very earliest days of SDR transceivers and has produced a wide variety of high-performance rigs. In recent years, their product development and production has focused on higher-end transceivers with the discerning DXer and contester in mind. Their signature series SDRs pack incredible performance, yet can be operated from modest PCs since most of the processing horsepower and hardware are all within the radio chassis. Flex has also developed a fully wireless touch-screen Maestro Control Console that can be used over a local network, or even the Internet, to seamlessly control a remotely-connected Flex SDR. Flex Radio SDRs can cost anywhere from $2,000 – $7,500 US.

The Flex-6600

Gary Wise (W4EEY), my go-to guy for all things Flex Radio, also notes:

“One of Flex’s newest models, the Flex-6600, includes 7th Order Contest Band Bandpass Filters and dual Analog to Digital Converters. Which means that, using this radio, one can listen on one band while transmitting on another. Contesters call this ‘Single Operator Two Radio’ operation, and if you can do it successfully, it leads to big contest scores. Having this functionality in one box, without additional controllers and interfaces, is remarkable.”

Indeed.

Two other SDR transceiver manufacturers with large user bases are the Sweden-based SunSDR and India-based Apache Labs. Both companies produce high-performance SDRs and, like Flex, set benchmarks in terms of transceiver performance. I will not comment at length about either company because I’ve not had the opportunity of personally testing their products, but I encourage you to search online reviews about their products.

Tabletop SDR transceivers

The Elad FDM-DUO transceiver is both a stand-alone tabletop and fully-functioning SDR when paired with a PC.

There are a number of full-featured tabletop SDR transceivers on the market. One of the first SDR manufacturers to build a fully self-contained tabletop model with PC integration was ELAD, with their FDM-DUO QRP transceiver. Tabletop SDRs at the time of the FDM-DUO’s release were very limited in their functionality when connected to a PC. Some of them had stripped-down applications and lacked features like spectrum recording and multiple virtual receivers. The FDM-DUO, when connected to a PC running ELAD’s software, gives the user full control of the SDR.  Indeed, the experience is identical to that of using the FDM-S2 mentioned above, however the DUO is also a transceiver. Since the DUO’s release, other SDR manufacturers have designed models with full SDR application integration.

The Flex 6600M is a handsome standalone SDR transceiver.

Recently, Flex Radio introduced their Flex “M” Signature Series SDR Transceiver. These tabletop SDRs can be configured with most of the SDR receivers Flex currently produces. Their displays are impressive and useful; indeed, the spectrum waterfall resolution and size is one of the best I’ve seen on a tabletop transceiver.  The front panel is large and sports a number of controls, the design harkening back to large contest-grade transceivers like the Ten-Tec OMNI VII and Orion series.

The SunSDR MB1 at the 2018 Hamvention.

This year at the Hamvention in Xenia, OH, I had a chance to check out the SunSDR MB1. Like the Flex M series, the MB1 sports a comprehensive front panel and an amazing assortment of connections on the back panel. As I took a tour of this radio––and it really did require a tour, it’s so densely feature-packed––I was most impressed by the thought that went into this stand-alone SDR transceiver. I love the front panel display, graphics, and overall ergonomics. I understand it will also deliver benchmark performance; indeed with prices starting at a steep $7,000 US, I would expect nothing less!

SDR transceiver summary

As we’ve pointed out in this part of our primer, pure SDR transceivers are a product for radio operators willing to invest more financially in order to take advantage of the advanced functionality and performance a true SDR can provide. At present there are surprisingly few players in the pure SDR transceiver market; this is a product category ripe for expansion. And as more manufacturers get into the game, I believe competition will direct prices into even more affordable territory.

Transceivers based upon SDR technology

The final category we’ll discuss is transceivers based upon SDR technology.  It’s a sign of the times, indicating the direction that all enthusiast-grade transceivers and receivers are likely heading.

The Icom IC-7300 transceiver

Because the fact is, whether or not you feel inclined to embrace SDRs in your radio world, you may be surprised that you already have: for many years now, radio manufacturers have built their transceivers and receivers on SDR and I/Q quadrature down-sampling technology. All of the transceivers introduced in the past few years that sport on-board spectrum displays––like the Icom-IC7300, Icom IC-7610, and the new Yaesu FT-DX101D––are, of course, based on SDR technology.

Many others, like the Elecraft KX3 and KX2, which look much more like a traditional radio, are also based on SDR architecture. Indeed, almost all of the major manufacturers implement SDR technology in their current product lines. Manufacturers have caught on, learning how to leverage SDR technology in a way that maximizes receiver performance while keeping the overall price more affordable than comparably-performing legacy radios of former days.

Yet while these radios are SDRs at their core, they often are limited in their functionality when connected to a PC; most can be completely controlled by a PC and many can even export their I/Q data, but usually they won’t offer the working bandwidth and the advanced functionality of a true SDR transceiver.

Conclusion

If I’ve piqued your curiosity about the world of SDRs, and have yet to add one to your shack, I would encourage you to invest in an SDR receiver––at the very least, in one of the affordable rigs mentioned in Part 2 of this series.

Speaking for myself, I was once a “knobs and buttons” radio operator who thought I’d never want to control a radio through a computer and monitor. But when I hesitantly invested in my first SDR, I found it eye-opening––not to mention somewhat democratizing, in that it sets all radio listeners on the same level, as the spectrum becomes visually understandable, and thus accessible, to all who encounter it. I found that if you love to listen, also being able to look at your audio, especially when editing or archiving, but any time you’re tuning around through the spectrum,  just clarifies and enhances your overall radio experience. I soon became hooked…and have never looked back.

Now, I can assure you, I’ll never again be without an SDR. The ability to visualize our radio spectrum via SDR’s virtual window is truly illuminative.  What’s more, I’d even venture to speculate that you may share in finding the experience, if you’ll forgive the colloquialism, pretty darn cool.

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Peter Tannenwald asks, “Are we really ‘revitalizing’ AM?”

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(Source: RadioWorld via Bill Patalon)

On AM revitalization, Peter Tannenwald asks, Are we really “revitalizing” AM, or are we walking around in circles?

Late on Friday, October 5, the Federal Communications Commission (“FCC”) released a Second Further Notice of Proposed Rulemaking in a five-year ongoing effort to “revitalize” the AM radio broadcast service. The new proposals continue a trend toward allowing higher power operation by smaller stations, by reducing nighttime signal protection for some 60 Class A AM stations located in the continental United States and 16 stations in Alaska. The end result would be less wide area coverage and more local radio service to the public.

To understand why the FCC is considering this action, it helps to understand a bit of the science behind AM signal propagation. AM radio signals travel through both the ground and through the air. At night, the airborne signal component (“skywave”) is reflected back to the earth from the ionosphere — a layer of the atmosphere extending from about 50 to 600 miles above the earth’s surface. The reflected signals may come back down to earth hundreds, if not thousands, of miles away from a station’s transmitter. Class A AM stations — formerly known as “clear channel” stations (no relation to Clear Channel/now iHeartMedia) — are powerhouses, transmitting with 50 kilowatts of power 24 hours a day – 200 or more times the power of the smallest AM stations.

[…]Signal reflection doesn’t work so well during the day, so the FCC has allowed other stations to occupy the Class A frequencies in other markets. But those stations have to curtail power during “critical hours” (two hours before sunrise and after sunset) and often have to reduce power to nearly nothing or shut down altogether at night. In today’s 24-hour-a-day, nonstop world, not being able to reach an audience at night is a losing proposition; so the FCC has yielded to constant pressure over the years to allow more power and longer hours of operation by those “other” stations, at the expense of long distance reception of Class A signals.

Now the FCC is proposing to go further, rolling back some previous restrictions on non-Class A AM stations and perhaps eliminating whatever remains (and it’s not much) of the protection of far-away reception. Under the proposals, which are sufficiently complicated that you should talk to your engineer if you really want to understand the details, Class A AM stations would be protected only within a higher strength signal contour (and so within a smaller area) than they are now; at least some, if not all, skywave protection would be eliminated.[…]

Click here to read the full article at RadioWorld.

FCC might reduce AM clear channel power

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(Source: Tom Taylor Now)

Are the protected night signals of monster 50,000-watt AMs “an anachronism?”
And is the FCC poised to do something that will frustrate late-night DX’ers? The Commission tries again to balance the role of Class A signals like KMOX St. Louis/1120, designed to serve listeners hundreds of miles away, with the desires of local AMs. The “skywave” debate is decades-old – but particularly urgent now, given the rising noise floor from all kinds of interference. The Commission just issued a “Second further notice of proposed rulemaking,” noting the rise of “FM stations, satellite radio and other media.” The first notice drew “a voluminous and diverse set of comments,” with some pointing out that “AM skywave service is sporadic and unreliable, often subject to overwhelming environmental interference, and unlikely to consist of programming tailored to the needs of distant communities.” But then there are questions about hurricane and other weather/safety warnings. In this notice, the Commission has ideas about changes to daytime, “critical hours” operation after sunrise and before sunset, and “nighttime hours.” One observer tells this NOW Newsletter says that cutting through the thicket of details, “It’s clear that there will be a further reduction in protection to the clear channel Class A stations, particularly at night. The main questions are how much protection they will retain.”

Click here to read at Tom Taylor Now.

SDR Primer Part 2: Exploring the world of SDRs for $200 or less

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The $22 RTL-SDR paired with a Raspberry Pi and employed as an ADS-B receiver/feeder.

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

Welcome back to the world of SDRs

Last month we covered Part One of our three-part primer on software-defined radios (SDRs). While last month’s Part One focused on the nomenclature and components of a functioning SDR system, Part Two will take a look at some affordable SDR station options that will propel you into the world of SDRs for less than $200 US. We’ll cover Part Three in November, and we’ll dive a little deeper into the rabbit hole and cover higher-end SDRs and ham radio transceivers with embedded SDRs.

SDRs are affordable

Photo by Kody Gautier

If there’s one thing I’d like you to take away from this part of our primer, it’s that SDRs are truly affordable. For less than the price of a typical full-featured shortwave portable, you can own an SDR that covers almost all of the listening spectrum, and that does so with excellent performance characteristics.

We’re lucky to live in a time of phenomenal radio innovation. When I first jumped into the world of SDRs, the least expensive SDR that covered any of the bands below 20 MHz was about $500. That was only a few years ago, in 2010 or so.

Yet in the past three years, affordable SDRs have become the dominant radio product on the market.  And these modestly-priced products have made the barrier of entry into the SDR world crumble overnight.

Today, even a $100 SDR has more features, more frequency range, and more functionality than a $1000 SDR from just a decade ago.  Times have changed dramatically; indeed, the pace of innovation in this craft is simply amazing.

Before we begin looking at some choice sub-$200 SDRs, I’d just like to direct your attention to the first part of our SDR Primer (click here to read). Specifically, I’d like you to note one element I discussed in that article:  the vital importance identifying your goals as an SDR owner. In other words, how do you plan to use your SDR? If you’re only seeking an SDR to listen to local ham radio repeaters, track cubesat satellites, or gather ADS-B information from aircraft, a $25 SDR will more than suffice. If you wish to use the SDR as a transceiver panadapter, or you wish to chase weak signal DX on the HF bands, then I’d suggest you invest a bit more.

I’d also like to remind you, as I noted in the previous article, that this primer will be limited in the SDRs I highlight. The reason for this is simple:  there now exists a vast ocean of SDRs on the market (just search eBay for “SDR” and you’ll quickly see what I mean) so all models simply can’t be included in this introductory foray. I’ll be focusing here on several SDRs that cover the HF spectrum and above. I’ll also focus on SDRs with which I have personal experience, and which I consider to be “enthusiast” grade among a healthy community of users. Of course, this part of the primer will only include HF-capable receivers that cost a total of $200 or less.

Let’s take a look at what’s on the market in order of price, starting with the most affordable.

$10-$25: The RTL-SDR dongle

No doubt, many of you reading this primer have purchased an RTL-SDR dongle. Over the years, I’ve owned three or four of them and have even purchased them for friends. These dongles originally appeared on the market many years ago as mass-produced DVB-T TV tuner dongles based on the RTL2832U chipset. Very soon, users discovered that with just a little hacking, the dongle was capable of much, much more than its original intended purpose.

The dongle resembles a USB memory stick. On one end, you’ll find a standard USB connector.  On the other, you’ll find an antenna port, typically SMA, to which one connects an antenna. Although it goes without saying, here’s a friendly reminder: make sure you’re choosing an antenna to match the frequency range you’re exploring!

I’ve seen this older model of RTL-SDR being sold for $9 at Hamvention.

Early RTL-SDR dongles couldn’t cover the HF bands or lower, but many models can now cover a gapless 500 kHz all the way to 1.75 GHz.

So, what can you do with an RTL-SDR dongle?  In short, quite a lot! Here are a few of this simple device’s many applications and uses in our hobby.  It can:

  • become a police radio scanner
  • monitor aircraft and ATC communications
  • track aircraft with ADS-B decoding and read ACARS short messages
  • scan trunking radio conversations.
  • decode unencrypted digital voice transmissions such as P25/DMR/D-STAR.
  • track maritime boat positions like a radar with AIS decoding.
  • track and receive weather balloon data
  • connect to VHF amateur radio
  • decode APRS packets
  • receive and decode GPS signals
  • utilize its rtl-sdr as a spectrum analyzer
  • receive NOAA weather satellite images
  • and so much more––! This list is not fully comprehensive by any means.  Check out this list of projects at RTL-SDR.com.

And, of course, you can listen to any signals between 500 kHz up to 1.75 GHz––essentially, most of the radio listening landscape.

Is $25 still a little high for your budget? RTL-SDR dongles can be found for as low as $10 US, shipped, on eBay. While the cheapest of these dongles may suffice for some radio applications, I’m partial to the dongle produced by RTL-SDR.com, since they’re built in a tough metal enclosure, have thermal pad cooling, as well as extra ESD protection. Amazon has an RTL-SDR.com dongle starter package with antenna options for about $26. That’s, what, the price of three hamburgers? Two orders of fish and chips? And worth it.

Many third-party SDR applications support the RTL-SDR dongle, but my favorite is SDR# (click here to download).

So, the major pros of this little SDR are 1) obviously, the price; 2) many, many uses; and 3) the fact that it’s the most popular SDR on the market, with a massive online user base.

What about negatives? Well, to be frank––aside from the dongle’s budget-busting versatility––the fact is that “you pay for what you get.” You’re investing just $10-$27 in this receiver, so don’t expect exceptional performance especially on anything lower than 50 MHz. On HF, for example, the RTL-SDR could easily overload unless you employ external filtering.

Indeed, I’ve never used the RTL-SDR for HF DXing, but I currently have three dongles in service 24/7:  two as ADS-B receivers, and one as a receiver for the LiveATC network. And these work hard. Indeed, It’s a workhorse of a device!

I suggest you grab an RTL-SDR and use it as an accessible step into the world of SDRs, and as an affordable single-purpose tool to unlock the RF spectrum!

Click here to check out the RTL-SDR blog SDR dongle via Amazon (affiliate link).

$99: The SDRplay RSP1A

When you invest a modest $99 US (or $120 shipped), and purchase the RSP1A, you take a major step forward in the SDR world.

UK-based SDRplay is an SDR designer and manufacturer that focuses on enthusiast-grade, budget wideband SDRs. SDRplay designs and manufactures all of their SDRs in the United Kingdom, and over the past few years, they’ve developed a robust user community, extensive documentation, and, in my humble opinion, some of the best tutorial videos on the market.

SDRuno windows can be arranged a number of ways on your monitor.

Although the RSP series SDRs are supported by most third-party SDR applications, SDRplay has their own app: SDRuno. Moreover, SDRuno is a full-featured, customizable application that takes advantages of all of this SDR’s performance potential and features. I should mention that installing the RSP1A and SDRuno is a pure plug-and-play experience:  just download and install the application, plug in the RSP1A to your computer, wait for the USB driver to automatically install, then start SDRuno. Simplicity itself.

While the RSP1A is SDRplay’s entry-level wideband SDR, it nonetheless plays like a pro receiver and truly pushes the envelope of performance-for-price, and for other SDR manufacturers, sets the bar quite high. The RSP1A is a wideband receiver that covers from 1 kHz all the way to 2 GHz; equally pleasing the longwave DXer, HF hound, tropo-scatter hunter, and even radio astronomer. This affordable SDR really covers the spectrum, quite literally. Not only does the RSP1A cover a vast frequency range, but its working bandwidth can be an impressive 10 MHz wide and via SDRuno, the RSP1A will support up to 16 individual receivers in any 10 MHz slice of spectrum. All this for $99? Seriously? I assure you, yes.

Think of the RSP1A as the sporty-but-affordable compact car of the SDR world. It delivers performance well above its comparatively modest price, and is fun to operate. In terms of DX, it gets you from point A to point B very comfortably, and is a capable receiver which will help you work even weak signals––and very reasonably!

If you’re looking to explore the world of SDRs, would like a capable receiver with great LW/MW/HF reception to do it with, but also want to keep your budget in check, you simply can’t go wrong with the RSP1A.

Check out the RSP1A via:

$167 US (125 GBP): FUNcube Dongle Pro+

Many years ago when I ventured into the world of SDRs, one of the only affordable SDRs which covered the HF bands was the FUNcube Dongle Pro+.

The Funcube Dongle Pro+, which resembles the RTL-SDR “stick” type dongle, was originally designed as a ground receiver for the FUNcube Satellite (cubesat) project initially made possible by AMSAT-UK and the Radio Communications Foundation (RCF). The original Funcube dongle did not cover any frequencies below 64 MHz, but the Funcube Dongle Pro+ added coverage from 150 kHz to 1.9 GHz with a gap between 240 MHz and 420 MHz.

In full disclosure, I’ve never owned a FUNcube Dongle Pro+, but I have used them on several occasions. I believe you would find that it is prone to overloading if you use a longwire antenna that’s not isolated from the dongle. In other words, during such use it seems to be subject to internally-generated noise. In my experience, the Pro+ worked best when hooked up to an external antenna fed by a proper coaxial cable.

To be clear, with the advent of SDRplay and AirSpy SDRs, the FUNcube Dongle Pro+ is no longer the budget SDR I would most readily recommend.

Still, the Pro+ is a very compact dongle that has a great history, and around 2012 really pushed the performance-for-price envelope. It still has many dedicated fans. No doubt, this product has had a huge influence on all of the sub $200 SDRs currently on the market, thus we owe it a debt of gratitude.

Click here to check out the FUNcube Dongle Pro+.

$169 US: SDRplay RSP2 & RSP2 Pro ($199):

The SDRplay RSP2 Pro

In 2016, after the remarkable success of the original RSP, SDRplay introduced the RSP2 and RSP2 Pro SDRs. The RSP2 is housed in an RF-shielded robust plastic case and the RSP2 Pro is enclosed in a rugged black painted steel case. In terms of receivers and features, the RSP2 and RSP2 Pro are otherwise identical

The RSP2 and RSP2 Pro 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.

The RSP2 series has the same frequency coverage as the RSP1A. Of course, to most of us, the big upgrade from the SDRplay RSP1A is the RSP2’s multiple antenna ports:  2 x 50-Ohms and one High-Z port for lower frequencies.

The SDRplay RSP2 with plastic enclosure.

As with all of SDRplay’s SDRs, their own application, SDRuno, will support up to 16 individual receivers in any 10 MHz slice of spectrum.

Bottom line? Since the RSP2 has multiple antenna ports––and two antenna options for HF frequencies and below–the RSP2 is my choice sub-$200 SDR to use as a transceiver panadapter. (Spoiler alert: you’ll also want to check out our summary of the recently released $279 RSPduo from SDRplay in this review or in Part 3 of our primer before pulling the trigger on the purchase of an RSP2 or, especially, an RSP2 Pro!)

Check out the RSP2 via:

$199 US: AirSpy HF+

Sometimes big surprises come in small packages. That pretty much sums up the imminently pocketable AirSpy HF+ SDR.

The HF+ has the footprint of a typical business card, and is about as thick as a smartphone. Despite this, it’s a heavy little receiver––no doubt due to its metal alloy case/enclosure.

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 is performance-packed!

Not to dwell on its size, but other than my RTL-SDR dongle, it’s by far the smallest SDR I’ve ever tested. Yet it sports two SMA antenna inputs: one for HF, one for VHF.

The HF port is labeled as “H” and the VHF port as “V”

When I first put it on the air, my expectations were low.  But I quickly discovered that the HF+ belies its size, and is truly one of the hottest sub $500 receivers on the market! Its HF performance is nothing short of phenomenal.

The HF+ is not a wideband receiver like the FunCube Dongle Pro+ or RSP series by SDRplay. Rather, the HF+ covers between 9 kHz to 31 MHz and from 60 to 260 MHz only; while this is a relatively small portion of the spectrum when compared with its competitors, this was a strategic choice by AirSpy. As AirSpy’s president, Youssef Touil, told me,“The main purpose of the HF+ is [to have] the best possible performance on HF at an affordable price.”

Mission accomplished.  Like other SDRs, the HF+ uses high dynamic range ADCs and front-ends but enhances the receiver’s frequency agility by using high-performance passive mixers with a robust polyphase harmonic rejection structure.  The HF+ was designed for a high dynamic range, thus it is the best sub-$200 I’ve tested for strong signal handling capability on the HF bands.

You can very easily experiment and customize the HF+ as well; easy access to the R3 position on the circuit board allows you to make one of several published modifications. “During the early phases of the design,” Yousef explains, “R3 was a placeholder for a 0 ohms resistor that allows experimenters to customize the input impedance.” He goes on to provide in-depth clarification about these mods:

“For example:

  • A 300 pF capacitor will naturally filter the LW/MW bands for better performance in the HAM bands
  • A 10µH inductor would allow the use of electrically short antennas (E-Field probes) for MW and LW
  • A short (or high value capacitor) would get you the nominal 50 ohms impedance over the entire band, but then it’s the responsibility of the user to make sure his antenna has the right gain at the right band
  • A custom filter can also be inserted between the SMA and the tuner block if so desired.”

Since the introduction of the HF+, it has been my recommended sub-$200 receiver for HF enthusiasts. If you want to explore frequencies higher than 260 MHz, you’ll have to look elsewhere. Also, note that longwave reception is not the HF+’s strong suit––although modifications to R3 and future firmware upgrades might help with this! Additionally, the HF+’s working bandwidth is 660 kHz; quite narrow, when compared with the RSP series, which can be widened to 10 MHz.

AirSpy also designed the free application SDR# to take full advantage of their receivers’ features and performance.

The AirSpy application (a.k.a. SDR#)

Installing the HF+ and getting it on the air is pure plug-and-play. While SDR# is a powerful and fluid SDR application, I actually use SDR Console more often, as it supports most of my other SDRs as well, and offers advanced virtual receiver and recording functionality.

If you’re an HF guy like me, the HF+ will be a welcome addition to your receiver arsenal. It’s a steal at $200.

Click here for a full list of AirSpy distributors.

Conclusion

If you haven’t gathered this already, it’s simply a brilliant time to be a budget-minded radio enthusiast. Only a few years ago, there were few, if any, enthusiast-grade sub-$200 SDR options on the market.  Now there are quite a number, and their performance characteristics are likely to impress even the hardest-core weak-signal DXer.

Still, some hams and SW listeners reading this article will no doubt live in a tougher RF environment where built-in hardware filters are requisite to prevent your receiver from overloading. Or perhaps you desire truly uncompromising benchmark performance from your SDR. If either is the case, you may need to invest a little more of your radio funds in an SDR to get exactly what you want…and that’s exactly where I’ll take you November in the final Part Three of this SDR primer series.  Stay tuned!

Stay tuned for more in Part Three (November). I’ll add links here after publication.

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