Category Archives: Reviews

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

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

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

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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Updated and Original Versions of the CCRadio-EP Pro Briefly Compared

Remember the American television game show To Tell The Truth? This very long-running show challenged four celebrity guests and viewers to identify the real “central character” in the midst of two impostors.I was reminded of this game show when attempting to tell the difference between the original and recently updated versions of C. Crane’s CCRadio-EP Pro receiver when viewing the front panels. If there’s a difference, I can’t spot it! You need to turn around the radios to see the new EP-Pro’s key feature: switchable 9 kHz/10 kHz tuning steps.

The only clue to the newest version of the CCRadio-EP Pro is the 9/10 kHz tuning switch on the back panel.

I recently met with a good friend and radio hobbyist from Oregon to compare a few selected portable radios, FSL (Ferrite Sleeve Loop) antennas, and the newest low-noise Wellbrook ALA100LN module that was introduced just a few weeks ago. I was particularly interested in a head-to-head match-up of my friend’s original EP-Pro versus my newly arrived EP-Pro (9 kHz/10 kHz steps) version.

I’m looking forward to Thomas’ usual thorough review of the new CCRadio-EP Pro, but I want to offer a few observations of medium wave tuning after my time with the two models:

  • On very weak daytime MW signals, the radios are equally sensitive except on higher frequencies where the new model excels to a moderate degree. It’s enough of an advantage to make the difference between catching an ID or not on a low, DX-level signal.
  • The new EP-Pro feels more accurate–and simply more enjoyable–to tune, thanks to the elimination of false “peaks” surrounding the main signal. This is a BIG plus for the new radio, and frankly the CCRadio-EP should have performed this way from the start. Kudos to C. Crane for correcting this problem, but I can understand why the original version was brought to market with the odd tuning quirk. It isn’t a deal breaker for most non-DXing purchasers.
  • I could not find an instance of soft muting on either radio. I listened for a while to signals barely above the noise floor, and never did audio “cut in and out” suddenly, a clue to soft muting. Both receivers are very useful for chasing weak MW stations…but the new version is highly preferred for ease of tuning because of the lack of false audio peaks.
  • With the tuning working way it should, medium wave channels “snap” in and out as you slowly tune. This took a little getting used to, but after a while I began to appreciate the sense of exactness with the newest CCRadio-EP Pro.
  • Fast excursions up or down the band (either radio) will blank the audio, recovering when you stop tuning or slow down. I believe this is simply a case of exceeding the AGC’s recovery time, not soft muting. It’s easy to live with, but granted the effect is not one of smoothness as found on traditional, non-DSP analog receivers. Successful DXing takes a slower approach anyway when scanning the band; casual listeners may be more annoyed by either version of the radio if they are used to very quick knob-cranking.
  • The Twin Coil Ferrite “AM Fine Tuning” control works well on both units, and gives significant gain to weak signals on either extremity of the band. I love this feature; it makes digging out the weak ones a lot more fun!

So, should you buy the newest CCRadio-EP Pro with the 9 kHz/10 kHz steps?

  • If you already own a CCRadio-EP Pro and are fine with the false tuning peaks and have no desire for the 9 kHz MW step option–keep your radio! Only on high band does the new model have a sensitivity edge. Especially don’t make the jump if you’re a casual listener and listen only to a handful of local stations, or a single distant station.
  • If you do not own a CCRadio-EP Pro yet, but are in the market, definitely buy the newest version. Be aware that you can only be assured of getting the newest model if you purchase directly from C. Crane. Amazon does not yet carry the newest version according to some reports.
  • If you’re a radio junkie and just have to have both…go ahead…we understand!

I also made a short video comparison of the new EP Pro versus the top-ranked Panasonic RF-2200 on medium wave:

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

 

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

The new ELAD FDM-S3.

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


SDR Primer Part 1: Introduction to SDRs and SDR applications

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

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

and/or,

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

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

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

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

Not your grandpa’s radio

Here’s how Wikipedia defines SDR:

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

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

Why would you want an SDR?

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

Bang-for-buck

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

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

Spectrum display

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

Powerful tools

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

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

Multiple virtual receivers

SDR Console makes managing multiple virtual receivers a breeze.

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

Recording tools

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

SDR Console recording dialog box

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

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

Constant upgrades

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

So, what’s not to love?

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

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

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

The ELAD FDM-DUOr (receiver).

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

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

Scope of this primer series

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

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

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

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

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

Assembling an SDR station

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

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

A computer

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

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

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

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

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

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

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

An SDR application

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

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

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

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

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

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

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

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

Types of SDR applications

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

Proprietary SDR applications

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

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

Free third party SDR applications

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

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

Paid third-party apps

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

Web browser-based  SDR applications

The KiwiSDR browser-based application

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

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

Choosing an SDR

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

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

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

Budget

Photo by Kody Gautier

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

Compatible applications

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

Frequency range

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

Recording and processing bandwidth

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

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

Portability

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

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

Recording features

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

Know your goal!

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

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

Scoping out the world of SDRs

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

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

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

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