SDRPlay Review vs RTL-SDR

Edit Nov 22, 2016: This post is about the older version, now called RSP1, not the newly released RSP2.


The SDRPlay RSP is a software defined radio receiver, covering frequencies between 100 kHz and 2GHz.
Available directly from the manufacturer (link) or from Ham Radio Outlet in the USA (link), or any of the worldwide distributors (link).
Disclaimer: Most of the equipment in this post was received from manufacturers as free loan or review samples. This has zero influence on what I write, but you need to know.
Also, SDRPlay checked the preliminary version for factual errors, their comments are included at my discretion. (After sending this over there were none).
I wanted to see if the SDRPlay is really that much better, and whether it's worth upgrading from an RTL-SDR based setup.

Beginner note: if words, terminology or concepts sound strange, please use google, or buy my book for 5 dollars written for people like you. It is available on Amazon (link), or by clicking on the blue image on the left. Thank you.

It's an unfair comparison


SDRPlay or RSP, used interchangeably, main features versus RTL-SDR dongles:
- 12-bit Analog-to-Digital conversion, (vs 8-bit), theoretically a higher ADC value is better,
- built-in preamplifier for VHF and up (vs external LNA4ALL (link),
- built-in Upconverter (vs external upconverter like Ham-It-Up v1.3 (link),
- built-in Filters (vs external solutions),
- up to 8 MHz bandwidth (vs 2.4 - 2.8 MHz for RTL-SDR dongles),
- "All-in-one" package (vs adapters and pigtails),
- no TCXO (vs TCXO with $20 dongles)


Costs


The USA is the most developed nation in the world with the highest per-capita GDP, yet 14.8 % of the population (ref, pdf) lives below the poverty line: over 45 million people get by on less than $500 a week. This is not a comment on fiscal policy, these are facts; especially in light of statements praising the SDRPlay as being "cheap".
The RSP is priced at $149 plus shipping in the USA, but costs significantly more elsewhere: for example, it 's close to ~$190 delivered to Ireland.
Manufacturer offers 6 month's warranty. RTL-SDR.com dongles officially come with 6 months, Nooelec gives you two years with the Plus series. However, I seriously doubt any maker named above will hesitate the slightest to replace a faulty unit after warranty expires.
To get even close to the RSP's claimed performance, we'll need to source components separately for RTL-SDRs.

No-frills without preamp (~$66), covers the same frequency spectrum, dongle plus upconverter and pigtails.
Budget equivalent ($92): Noname RTL-SDR dongle for $10 (R820T2, no TCXO), bare upconverter board for $50, MCX-SMA and SMA-SMA pigtails ($6), LNA4ALL ($26). Five different suppliers.
Sensible equivalent ($107): upgrade dongle to TCXO (+$15), either from rtl-sdr.com or Nooelec.
Top-components equivalent ($135): add a metal case to the upconverter (+$22), use better pigtails (+$6).


Questions for the reader


Ask yourself whether the answer is "Yes" to any, or all of the following:

- Do you have ~ 150-200 dollars for an SDR receiver?
- Would 8 a larger visible frequency span make your life / reception experience better?
- Do you have a fast enough computer for 8 MHz span?
- Do you enjoy chasing really weak signals? This ties to the next question:
- Do you possess the antenna systems, knowledge and time to get the best out an RSP?


In the box and first impressions

Signed-for DHL shipping, UK to Ireland took two days. I love no waiting.
Small black box in see-thru plastic, looks and feels like a Christmas bauble box.
The receiver itself fits into the palm of my hand, not that I would want it to: plastic quality and tactile feel is terrible, midway between a toilet brush and disposable cutlery.
In comparison, a Nooelec metal case is reassuringly solid, and rtl-sdr.com's dongle is so smooth with its rounded edges and satin finish that it's good just to pick it up.
And no power/data USB-B cable. The target market will, obviously, possess a suitable cable, but at the end of the day, for $150 you get a paperweight, as the device is not usable out of the box. No antennas nor cables whatsoever, not even a small telescopic. Come on.
Summary: "no supplied cable" is one of my pet hates, but for $150 this cannot be ignored.
The feel of the actual unit is so awful I didn't want to touch it, and that resilience hasn't changed.
A metal case should be compulsory at this price point, or at least the option to order a complete package with a large telescopic on a magnetic mount and power/data cable with chunky ferrites on both ends.


Secondary opinion: a woman's perspective



The suffering subject is my mother this time.
"I love the rounded edges, the plastic feels smooth and inviting. Only two holes, probably I can put this together. This would look good on an executive desk, the logo with the lightning is well made.
Handing her a metal cased upconverter and Nooelec dongle, connected with a pigtail:
"Why all the wires? I don't like the metal case, what would happen if I accidentally knock it off from the table? It could damage the tiles, with the plastic at least the case would break.
I tell her the SDRPlay costs more than double and offers much more for the price:
"I'd save up and get the little black box, everything in one box. No cables."

Conclusion: Mothers are always right.


Support


Big brownie points for official support, easy to navigate website with links to required configuration files, along with helpful guides for software setup - all front-end software worked seamlessly following manufacturer instructions.
Facebook group available, closed but I got approved in a few minutes, active members, questions get answered.
I'd recommend the RSP purely on support alone, even if you have no clue what to do, or wonder how to set up HDSDR for shortwave.
The possibility of asking someone for help cannot be underestimated.




Hardware



If your computer runs RTL-SDR dongles, it will run the SDRPlay.
Sample size (how much frequency is visible) determines computer requirements, to get the highest span a very powerful processor (read: $$$) will be required.
Intermediate laptop: On an Intel Core i3-2330 M @ 2.2 GHz, 8GB RAM and SSD hard drive, RTL dongle at 2 MHz sample rate had 35-40 % CPU load. SDRPlay at 5MHz sample rate, processor stayed around 20-25 % utilization figure.
A laptop like this costs from 300 dollars and up.
Normal Laptop: On an Intel Core 2 Duo @ 2.0 GHz, 4GB RAM, with the SDRPlay only 2MHz sample rate could be selected without audio stuttering.
A laptop like this costs from 200 dollars and up.


No driver, no port hassle


Once the initial driver installation completed, the SDRPlay can be used with any USB port, and usable as a TV tuner without driver reinstallation. In comparison, the same USB port must be used with dongles and TV tuner use requires a different driver.
If you ever tried to restore a wireless keyboard driver in Device Manager, because you mistakenly overwritten the driver with Zadig, you'll appreciate this. Plus no bother with external USB hubs: see a free USB port and you're good.





Testing setup and methodology

Testing took a month: in four cities, various urban / suburban RFI environments, and down the country at several locations .
No fancy pancy noise reduction measures. USB extension lead used with bias-T enabled rtl-sdr.com dongles and Nooelec dongles in a metal case, plus LNA4ALL and LNA4HF from Adam.
VHF: Commercial discone, antenna splitter, identical coax lengths with Nooelec pigtails (which are abused for a long time without any sign of wear, good stuff). Standard supplied RTL-SDR collapsibles on magnetic mounts were also used.
HF:  multi-stranded copper wire, 1.5 mm diameter. Various antenna lengths, with and without Balun One Nine and homemade 9:1 UnUn.
Methodology: I'm new to SDRPlay and its myriad levels of gain settings, but tend to think I know RTL dongles a little bit.
Consequently, I tuned to a signal with an RTL dongle, tried to get the best reception with either SDR# / HDSDR / SDR Console, then attempted to get same or better performance with SDRPlay in the same software.
When I've seen a juicy weak signal with the SDRPlay, I tried to get it with the applicable dongle configuration.

Attitude


I'm grossly uninterested in technical specifications, couldn't care less for published or claimed figures, or in the 8-bit vs 12 bit debate; I live in the real world, not in a lab.
To start an analogy, I've driven a small roadster (Mazda MX-5) and had much more fun than in a car with twice the power (Subaru Impreza). Was the Mazda a better car? Yes, for me. Did Subaru won numerous rally championships? Sure.
Everything depends on personal circumsances and what you enjoy.
Furthermore, I don't wish to build a statue to either the SDRPlay or RTL dongles. The purpose here is to provide insight, as I'm lucky enough to receive  gear from good manufacturers and have the time to test them.
I simply sit down and enjoy listening to radio, like I do for the past 25+ years.
Please feel free to make an informed decision, it's your money after all.


Software front-end choices


Runs best on software you might not have heard about, namely HDSDR and SDR Console - manufacturer offers free, and excellent Getting Started guides on both.
SDR Console looks 21st century, v 2.3 used for testing, v3 looks nice but freezes and crashes too often. Natively supports the RSP and works with RTL dongles too.
HDSDR looks archaic and control buttons are small, but works wonderfully, uses the least amount of resources.
SDRSharp is supported and works, but often froze after an extended session; it's still the easiest to use, but as its developers are tied to the direct competitor AirSpy, it's not the best choice.


Gain



RF gain is the most important setting with a receiver, and boy, you have options with the SDRPlay.
Remember the good ol' days when you had a slider or knob for gain, played with it until you got the best reception? Now, after installing the suggested plugin, in SDR# and HDSDR a weird-looking flowchart replaces the single slider, which not only looks complicated: it's complicated. Why the need for all the symbols? Settings panel also cover a lot of screen estate in HDSDR and SDRPlay.
A mental recalibration for adjusting RF gain is necessary, as you set "Gain Reduction". Higher number = less signal, but at least the slider works as expected, pull up = more gain.
Fortunately, manufacturer provides a technical note (link), with such sentences as:

LNA_Threshold = Thermal Noise + 10 x LOG(IFBW) + NF with LNA Off + SNRMIN + Margin

It makes sense after a few reads. Really.

Essentially, you can adjust a lot of variables, such as when the LNA kicks in; I found that after some head-scratching, much better fine tuning is possible, gain can be set in 1dB increments vs 2.5-3 dB steps with RTL dongles.


Performance


The SDRPlay RSP offers better reception than any RTL-SDR dongle.
That's not a surprise, $150 beats $10 dongle. Wow.
The RSP has better sound quality on audio signals. It is small, but manifests every time during long listening sessions due to intelligibility.
Even on small and grossly unsuitable antennas, the SDRPlay could receive weak signals dongles could not; the difference was catching words from a conversation or not hearing anything at all.
If you love airplane chatter, the SDRPlay is the weapon of choice, RTL-SDR.com dongle with a preamp (bias-T LNA4ALL) could not get the same clarity and "be there" sensation.
Having a large frequency span is so great you'll wonder how you managed to survive without it.
See an emaciated worm in the waterfall? Click and hear, or write down the frequency, to be used later with a dedicated handeld scanner or in software.


The fly in the ointment


There's always a catch: in an urban environment, signals which should not be there, primarily broadcast FM stations appear everywhere.
Here's a shot around 160 MHz:

And I mean everywhere. Below 250 MHz, changing the local oscillator frequency in SDRConsole might help a bit.


On upper VHF and low UHF, pandemonium reigns. Fancy some DVB-T? No? Sorry, you'll get it.
There's not too much action between 200 and 420MHz in my part of the woods, but I can just as well forget this part of the radio spectrum. Weather balloon telemetry? Gone.


Interference seems to disappear above 420 MHz, usual suspects merrily come in.

Comparison against RTL-SDR dongles and a HackRF:



Same everything, strong broadcast FM signals with the SDRPlay.
Whether this affects you is down to personal listening habits and preferences. It is a serious shortcoming in an urban environment, and disappears the farther you're away from cities.
But it's not black and white, there're 256 or 4096 shades of gray, especially when cost enters into the equation.

Compared to plain RTL-SDR dongle



Don't want shortwave or can't stand static? At the end of the day, a vanilla RTL dongle will get you about 50-60 % of the RSP's performance (between 24-1800 MHz) for significantly less.
Additionally, a top RTL-SDR dongle, such as samples from Nooelec or rtl-sdr.com will offer a ready-to-go package with usable antennas.
However, the SDRPlay's advantage is there and will be audible in a side-by-side comparison. But sleep well, you won't miss really weak signals with RTL dongles: you simply won't see them.

Compared to RTL-SDR with LNA4ALL


Still no shortwave, but this setup lets you place the preamp at the antenna. Imitating a newbie I didn't do that, still with two identical antennas and 30 feet / 10 m coax runs, in over two weeks, I managed to find only a few signals that I could not tune with this combo and the SDRPlay could.
It must be also noted, again, that the RSP was better on my ears for extended listening sessions due to less noise and crackling.
For $150, I'd get an rtl-sdr.com dongle and an LNA4ALL, enable bias-T and place a nice discone as high as possible. Radio signal reception is all about antennas and antenna placement, plus especially with long coax runs in an urban environment, an antenna mounted LNA will beat a receiver-mounted LNA.

Compared to RTL-SDR with upconverter


Lazy shortwave listeners rejoice: tuning really weak broadcast stations on a discone (just about visible in waterfall, fading in and out with headphones) with the RSP was each_and_every time a positive surprise.
If you can't erect a longwire or wish to use one antenna for everything, the SDRPlay is a good solution.
Using a 20 ft dipole with a 9:1 Balun and RTL dongle based setup I could easily copy hams, listen to AM broadcasts etc; doing the same was easier with the RSP due to to better sensitivity, filtering or whatever: it was easier with the SDRPlay.
In an electrically quiet environment, read middle of nowhere, the RSP excelled on broadcast AM stations for evening-long listening sessions. Like listening to the breakfast news on the way to work, only the source was on the other side of the world.
Was it twice as good? Hell no. But that tiny bit of advantage wax enough justification to choose the SDRPlay if I wanted to hear something.
I was also testing shortwave antennas for the Third Edition, and the antennas played a bigger part in listening enjoyment than the receivers. However, a  performance improvement with a better antenna was much more evident with the SDRPlay.


Drift and temperature


TCXO dongles are spot-on, the SDRPlay is less so: the difference is minuscule, and nobody will care about it, especially that the RSP does not drift and, unlike RTL dongles, does not get excessively warm.


No bias-T


At this price level I want software-selectable bias-T (like HackRF), or simply the option to enable it with a hardware mod (like rtl-sdr.com dongles).
Very likely it will be included with the next revision.



Only one antenna port



Why? The SDRPlay is made by hams for hams, and nobody uses one antenna. In a fixed setup:
- one Yagi and one general for shortwave,
- one for airband and 160 MHz-ish for action,
- one for UHF,
- two more for special interests such as Weather Sats or Balloon telemetry or ADS-B.

Antenna switches are soooo last century, it could be done in software, would cost a few extra connectors. Two more would be great.
Speaking of: please provide N-type for pro antennas, and a 9:1 UnUn terminal for longwires. Few cents on an industrial scale.


Day-to-day living with an SDRPlay


The RSP is extremely simple to use, connect antenna to receiver and receiver to computer, fire up software and off you go. This, plus 5 MHz span and the warm fluffy knowledge that if the antenna can get the signal, the receiver will do a great job makes it a winner in my book.
Convenience is the key word with the RSP: Not having to screw components together is priceless. Changing from VHF to HF requires no switch as with a Ham-It-Up and no offset adjustment in software. These are small things, but I didn't had to get up.
Carry driver installer and SDRConsole on a memory stick, a collapsible antenna on a magnetic mount and be ready for nearly anything. Demonstrations or explanations are much more convincing if the item in use looks simple and works simply. A dongle and upconverter with pigtails and USB cables looks like a nerd's Sunday afternoon; an SDRPlay looks like kid's play and just as easy to assemble.


Evolution


Learn to walk before you run. If you're a beginner or novice reading this to decide whether should you invest in an RSP: the answer is no. Buy an RTL dongle, try to understand why and how radio works, then spend savings on a good antenna and time with front-end software.
The SDRPlay is the only choice after an RTL dongle, anyone asks and I'll wholeheartedly recommend it.
Airspy and its derivatives are fundementally flawed as require an upconverter: it's not just one small black box.
The HackRF is significantly more expensive, but transmit-capable, looks and feels a more upmarket premium product. Yes, review soon.
The SDRPlay's strengths are evident even on inferior antennas, but buying a Ferrari to drive to the nearest convenience store is kinda silly. You'll need a proper antenna system and LOTS of time and knowledge to get the best out of it.
If money matters, RTL-SDR dongles and associated paraphernalia will get you close performance-wise, but will be more hassle.

Conclusion



Large frequency span, everything in one small box and manufacturer / community support are key selling points.
However, if money matters, you can get almost the same performance with an RTL dongle, suitable accessories and knowledge for less.
Total beginners: buy an rtl-sdr.com dongle, supplied antennas are great and will be compatible with the SDRPlay when you upgrade. Read, learn, build antennas, and when impedance matching, UnUns or Baluns become second nature buy an SDRPlay. Steep learning curve awaits if you jump directly into the higher echelons of  radio head-first, and I'm afraid you'll give up before you surmount the peak.
The SDRPlay is a great radio engineering milestone, and I'm happy that it's available: it gave me joy when I digged out a weak station from the noise floor. Add software-selectable bias-t, smooth silky metal case, two more antenna ports, and keep up the good work with support and we'll have a world-beating receiver.
Upgrading from an RTL-SDR setup is warranted IF the antennas are in place AND the receiver is the bottleneck in your setup.
Transitioning will take weeks, but a mind once subjected to a new experience will never go back to its old dimensions to paraphrase Kurt Hahn.
Do you got the money and time? If so, head over to the manufacturer's website and order one.

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