SDRPlay are a British company and they have been manufacturing SDR radios since 2015. Their first model was the RSP1 which had a 2 tone grey/blue case.

All of SDRPlays radios are designed and built in the UK which is very surprising as most products like this are built and assembled in China or Taiwan.

Around 18 months ago (November 2017), a new model appeared, the RSP1A.

With a price of around £93 ($120usd in the United States), This model has become very popular indeed for those enthusiasts who are upgrading from R820T dongles or radio fans who are making their first SDR radio purchase.

The RSP1A has all mode coverage from 1khz-2ghz with no gaps,  improved filtering compared to the older RSP1, and much lower cost per unit.

For the aviation enthusiast, departing from a traditional scanner to an SDR radio is a huge leap.

Especially so if you are a home/base station listener like me.

Do not expect analogue radios and SDR digital radios to be the same, they are most definitely not.

Aside from processing the signals (which is very different) it is the software and user interface of SDR radios which plays a very important part in the whole experience.

I would put software as much as 50% importance in selecting an SDR radio, the remaining 50% would be the physical device itself.

 

Anyway, on to the RSP1A,

 

Here is the unit and packaging.

Here are the case measurements.

 

A word on the dimensions, my measurements (97mm x 85.5mm x 32mm) are different to those that are quoted on the spec sheet. Perhaps a revision of the casing has taken place or perhaps a change of supplier.

 

Ref: https://www.sdrplay.com/wp-content/uploads/2018/01/RSP1A-Technical-Information-R1P1.pdf

No sealed/bonded case here (which is great). Just 4 screws to remove from the underside.

 

 

Now we can see the interior of the unit.

 

Note the matt grey interior coating which I understand is anti-static and applied to prevent locally generated unwanted signals entering the radio. Also the coaxial pigtail SMA connector lead which connects to the main PCB with one of those push fit laptop wifi card connectors.

A closer look at the main PCB.

 

Note the use of a  “printer style” USB 2.0 Type B socket which is shielded.

 

A robust choice of connector , one that will survive the rigours of plugging/unplugging & experimenting by a keen radio enthusiast.

 

 

The reverse side is quite bare in comparison aside from the 4 solder points for the USB socket power and data, and 2 more for its shielding can, there isnt much to see here.

 

 

For those who were observant, full marks if you spotted the Revision 4 (R4) etching on the PCB on the lower left corner.

 

 

On to operation.

I am a relative newcomer to SDR radio but there seems to be two distinct methods of operation for most users.

1. Those who connect the SDR unit directly to their computer via a USB cable.
2. Those who connect the SDR to a local network using either another computer such as a small single board computer or Intel NUC as a host and monitor the radio from elsewhere using a laptop. Streaming the audio over wifi . This gives the user the freedom to set up the SDR inconspicuously and then listen from anywhere in the home or garden. Some users host their SDR radios on the internet for the wider community. The possibilities are limited only by a users imagination.

With the SDRplay RSP1A both methods above are possible.

 

Method 1 : Connecting the RSP1A to your pc directly with a usb A-B cable.

Setting up the unit was very easy using a modest HP laptop PC and first I used the recommended SDRuno v1.3 software which was recently released.

Download the software, run it, check that the RSP1A appears in the device manager, Only plug in the USB lead when the prompt appears on the screen (Not Before), and SDRuno will be ready to start in no time.

Provided the software can “see” the device in your windows device manager, Hit the start button and you will be greeted with something like this,

 

Yes, an impressive layout isnt it ?

Took me a while to figure things out though. A lot of buttons and controls, some would say too many. Once you read the relevant pages in the user guide,things get a lot easier. Allow at least an hour to become familiar with the software, if you have migrated from SDR#, you will instantly realise that SDRuno does things in a very different way. That is not to say SDRuno is worse than SDR#, its just a matter of becoming familiar with different software.

It should be noted that during my initial tests over 2 weeks, I raised 3 support tickets with SDR play.

All 3 tickets were initially answered within 5 minutes,and furthermore, all 3 were solved to my full satisfaction, the longest taking just 1 hour where 8 messages were exchanged in total. This is very impressive. A newcomer will need some support with SDRuno at some point and its good to know that someone from SDRplay is out there to help you.

When I tuned around the VHF airband (my primary interest), I instantly noticed a very nice sounding audio, full and rounded.

About as different as it could get from rtl dongles, and even the formidable Airspy R2 does not deliver such pleasing audio “straight out of the box”.

The filtering options of SDRuno are very useful and for VHF airband I found the 8k filter to give the best performance overall.

Within the latest release of SDRuno v1.3 is a new feature, the ability to store and scan your own custom selection of frequencies.

For some this may seem to be an easy thing to add to an SDR program but it is not. Significant work must have been done behind the scenes at SDRplay to finally satisfy their loyal following of users who have been asking for this feature just about as long as the RSP1A has been in existence.

It is a very useful and well laid out feature now integrated within SDRuno software, scanning your own custom memory channels is easy.

Here is a quick video demonstration. Click on the lower right hand corner to expand to full screen, it gives a much better view of what is going on.

 

 

Station Equipment : HP 8440P Elitebook laptop PC 120gb ssd ,4gb ram windows 10, SDRPlay RSP1A  running SDRuno v1.3 & connected to attic/loft mounted J-Pole from Superyagi Antennas.

 

For those who like simplicity, there are other choices of software.

The excellent software package SDR Console V3 by UK based software engineer Simon Brown teams up with the RSP1A with no fuss at all.

Another package you may like to try is HDSDR by Mario Taeubel (DG0JBJ) from Germany.

I used SDRuno for the majority of the time when testing out this radio as the other alternatives mentioned above did not offer a scanning facility.

For a VHF /UHF airband listener, the ability to scan your own custom memory frequencies meant that SDRuno was the clear winner for me.

 

The RSP1A does have unbroken coverage from 100khz to 2Ghz and so, without any add on hardware, you can listen to HF airband.

This is a big advantage in comparison to some other SDR radios many of which require down converters (at additional cost) to achieve reception on frequencies below 20mhz.

Not necessary with the RSP1A, you have everything you need in one box. Just connect to a suitable HF antenna or long wire and you are good to go.

Alternatively if you are using the RSP1A as a base station radio, you can have VHF/UHF and HF coverage by using 2 antennas and a simple coaxial switch.

 

Here is the “field style” HF setup which I used in my garden for the test.

 

Station Equipment for HF Testing : HP 8440P elitebook laptop PC (windows 10, 4gb ram,120 gb ssd), 10mtr end fed wire commercial grade antenna with matching unit by G4ICD, some Sony headphones and the SDRplay RSP1A of course.

 

Antenna Supplier : https://www.ebay.co.uk/sch/g4icd/    

 

Now and again this commercial antenna supplier has units left over from larger production runs, keep an eye on the ebay shop to pick up a bargain. The quality is second to none.

 

 

I attached the RSP1A directly to the laptop via USB. Although the antenna used was far too short for the 5mhz band, and the antenna height was just 6ft, the RSP1A made a decent job of pulling in some test Volmet stations.

Here is a sample of reception on HF airband using my back yard “field test” listening station set up in 5 minutes flat.

Again the video is best viewed in full screen mode as some of the buttons/controls are quite small.

 

 

 

 

 

Method 2 : Connecting the RSP1A to your home network and stream the audio over wireless.

 

SDRplay have recently published a piece of software to enable streaming of the audio over a tcp connection.

The software is called RSP TCP Server and a guide to its use can be found at the link below

https://www.sdrplay.com/docs/SDRplay_RSP_TCP_Server_Guide.pdf

This enables the user to use a small single board computer such as the raspberry pi3 as a radio server and stream the audio output to other computers/devices in the home.

Sadly, at the time of writing, there is no facility to connect networked devices to SDRuno software. (Update see notes at bottom of this section)

It seems a little crazy for SDRPlay to release network connection software but a user must rely on third party applications to use it.

This will draw users away from SDRuno which seems a little strange.

I tried RSP TCP Server out with a raspberry pi3  the excellent  HDSDR, the stream worked okay but of course there is no scanning facility on HDSDR.

The overall quality of the streaming audio output using RSP-TCP Server was not as seemless or as slick as the Airspy R2 receiver using their spyserver software (that is absolutely superb) but having said that, the RSP1A is considerably cheaper to buy.

RSP-TCP Server is a very good try by SDRPlay , its very useable and extremely stable when used with either HDSDR or SDR Console but you cant help thinking that this program should be mated up with SDRuno and its recently added scanning options. That would be a massive leap forward.

Update : Jon Hudson the boss at SDRPlay informs me that a tcp/client connection is on the official road map for SDRuno. This feature should be available in the coming months.

 

What I liked about the RSP1A.

Unbroken coverage from VLF to Microwave all in one unit..amazing !

Memory Scanning and Frequency sweep function in SDRuno.

Audio quality is really great using SDRuno.

Lots of filtering options when used with SDRuno software.

View 10mhz of the spectrum at once anywhere between 100khz to 2 ghz.

Use of a full size USB B type socket.

Much lower noise floor than Airspy R2, No issues with noise even with a 3mtr long usb a to b cable.

Runs relatively cool, even when pushed very hard. (Tested with case removed).

Blisteringly fast response by manufacturer to support tickets.

Feedback good or not so good is welcomed by the company which is refreshing.

SDRuno development is constant and when the new features arrive they are very well executed.

Value..The best out there given what you get for your cash.

Designed and manufactured right here in the United Kingdom and sold all over the world..Yes we still make very good quality items right here in GB !

 

 

 

What I didnt Like so much.

No TCP/Client connection facility in SDRuno software. (Coming soon, see note in connecting via network above)

Loads of downloads/guides including an 80 page manual on SDR uno which covers absolutely everything, but there isnt a 2 page quick start guide with just the essentials to get some sound out of the radio within a few minutes of connecting up.

SDRuno is very good software let down slightly by the screen being far too busy for a beginner. There is a good chance that some users will be driven away to other software alternatives by SDRunos over complicated “first look and feel”. There is No “easy” mode (Suggestion : far less buttons/, just connect the rx , gain is auto set to 5, set a freq and mode, press play..thats it). As said, If you are patient and take some time read the manual and find your way around SDRuno, you will be rewarded.

No OEM metal case as add on accessory or option (There is one out there in “SDR radio land” sells at $30usd but no offering as yet from SDRplay, I think a lot of users may welcome this judging by the feedback of purchasers of the third party unit).

 

 

 

 

The bottom line.

I suppose it really is a choice of method of operation.

Connecting with a USB cable to your computer, the RSP1A will perform admirably and deliver everything you expect from a top quality radio.

 

Connecting via a network , The RSP1A can do this when running RSP-TCP Server, the listening/audio streaming experience is very acceptable but not nearly as smooth or as slick as the Airspy R2 running their excellent spyserver software. Its your listening station and your call . If network streaming is your chosen method of connecting your station ,You have to decide if the additional cost of the R2 is justified.

 

The SDRPlay RSP1A really is a revelation in SDR radio to have a “HF/VHF/UHF right up to microwave in one box, and best of all the cost is just circa £90 in the UK or $120usd in the US.

The performance out of this thing is nothing short of amazing.

Thinking about taking the plunge into the world of SDR radio or a serious upgrade/substitute for your RTL dongle ?

If you are an airband fan civil or mil ,The RSP1A will not disappoint.

Think about it, the RSP1A retails at less than the cost of the very popular and highly rated Uniden UBC-125XLT “pocket rocket” scanner  and significantly less than a Uniden BCT-15X or Whistler WS-1065 base station scanner.

In fact instead of buying a BCT-15X/WS-1065 base station , you could buy an RSP1A to use as an all band/all mode base station listening post plus a UBC-125XLT for airfield spotting trips and still have a good amount of change to put in the funds pot for that new antenna !

Strange but true !

 

It seems as though SDRPlay have squeezed just about everything on the wish list for the aviation enthusiast listener into this box of electronics and kept the price very affordable. The RSP1A has set the bar very high indeed when it comes to value for money.

At this price point, nothing even comes close. Insane value when you think about it.

I can thoroughly recommend the RSP1A from SDRPlay, it is everything an aviation enthusiast listener could ever want in a base station radio, and some !

 

Here In the UK I found RSP1A for £92.70 from a very reputable company “sdr-kits”  https://www.sdr-kits.net/

https://www.sdr-kits.net/index.php?route=product/product&product_id=136

Shop around and compare pricing in your region/country, SDR Play have a world wide network of distributors.

 

 

Update : Is the Airspy R2 on your short list ?

 

Check out the review of that great receiver here

New SDR radio purchase, Airspy R2.