Software Defined Receiver
SDRplay RSP1 "WideBand SDR"
Our sincere gratitude to Sungchul Cho , as he made the SDRplay RSP1 review possible.”Thank You !!”
The UK made "SDRplay RSP1" SDR. Black plastic cabinet using a SMA antenna connector.
10 khz to 2 GHZ coverage (no gaps). Full HF coverage with no silly converters too. (manufacture photo)
Approx. Test Sample Serial Number : #2501xx#14#92x
Country Of Manufacture : United Kingdom
Review : SDRplay RSP1 "WideBand SDR" (software defined receiver)
*** What is a "SDRplay RSP1" ?? / No USB 3.0 Sockets !
The SDRplay RSP1 is a fairly low
cost SDR (Software Defined Receiver) "computer connected" device that features full radio
spectrum coverage without any silly converters getting in the way. One
side mounted SMA antenna connector for all ranges. 12-bit architecture
allows for improved dynamic range over the lower cost 8 bit dongles. There is
even limited band-pass filtering inside its smooth plastic box. Power
is supplied via the host computer USB port via a USB cable, so no
additional external power supplies are required.
Low current consumption (well under
200 ma) along with many operational platforms offered makes for a nifty
Android SDR as well (not tested, requires Java with Android). In our
testing here we will be limiting the scope to Windows 7 operating
systems only (64 Bit). Sorry, we did not test this device on any
other Windows OS (Windows 8 or above) or platform. Important Note (as
experienced in testing) : Be sure and plug the SDRplay RSP1 into USB 2.0
socket on the host computer (NOT a 3.0). Yes USB 3.0 are supposed to be
backwards compatible, but in the real computer world many are not so
may not work properly with the device (which was made for 2.0 only).
Any new owner needs to supply the proper high quality USB cable and connecting antenna cable as neither is included.
*** Genuine Plastic Case / Cool Operator ***
Question has been raised a number of times around the internet, “Why is the SDRplay RSP1 not sold in a metal case ??”
As Jon Hudson G4ABQ of SDRplay
“The problem is that the biggest
source of interference is the USB cable and the USB comms...putting in
a screened box can often cause the USB interference to get “trapped”
inside and generate more problems than it actually isolates.”
that NOW they sell the updated RSP2 model in 2 versions. One in a metal
coated plastic cabinet and even a all METAL case version. Hummm...so
what was said in the last paragraph is perhaps not so valid after all
?? In any event in our testing with the host computers and proper
cabling we never experienced any issues here using decent outdoor
Aside from that it is in a most sturdy “plastic box” about
the size of an over sized Klondike Ice Cream bar. It is held together
with 4 screws, so no heat welded or glued together cases here. 4 small
stick-on rubber like feet were added to keep it from sliding around on
There is a female SMA antenna
connector (early versions used a female F fitting) and connection to
the computer is via a B type USB socket. Certainly a much sturdier
connector being used here say over a Mini or Micro USB.
Being in operation for hours, the case remained cool (only ever so slightly warm). It is not using a TCXO, but overall stability appeared to be most adequate.
*** Full DC To Daylight Coverage ***
Receiver coverage is from 10 kHz
right up to 2 GHz with no gaps. How they got around the old and
extremely outdated US federal laws that restrict coverage in the 800
MHz band with ANY radio receiver for the US general public is unknown.
It has no FCC OET ID on it and again unknown why that is ?
*** Host Computer : Dual Core OK , but best with a FAST “Quad Core” Processor ***
Unlike more expensive boxes
(Perseus, Bonito, Elad etc) these bargain SDR devices
make much more use of the computer resources to make it happen (with
much less internal hardware). With the more pricey critters, a computer
with a single core processor with low memory was possible. Even a
processor running at only 1.5 GHz and just 512 MB of memory.
Yes, one can use the SDRplay RSP
with a Microsoft Windows computer with a more limited “Dual Core”
processor around 3 GHz at only say 4 GB of RAM (Memory) and only using
a limited scope bandwidth (2 MHz sample rate, IF Bandwidth at 1.536 MHz or less). This is what was used for most of the
testing in this report in fact.
The slower the computer the worse the
performance / dropouts and even lockups are possible. Any additional
programs running along with it makes any limited computer recourses be
even worse. Don’t even think of using an old "single core" computer at
any speed, you will probably be disappointed (if it works at
As it always goes with computer software/hardware, this will vary with the SDR program used. Connected to a speedy 3.0 GHz QUAD core
computer and say have 8 GB of memory, it will be dropout / doggy free
and the user will be a happy camper.
*** Driver / Tested Software (using "Windows 7" 64 and 32 Bit)***
Mirics API Driver
The Mirics (API) driver is the first
software that needs to be installed before the USB cable is installed
for use with ANY software. No installation issues at any time with 4
different Windows 7 computers in testing. Version tested was 2.13. EXTIO version tested up to 4.2. It is highly recommended that these are kept up to date.
NOTE : SELECTED SDR
Programs come packaged with the SDR Software / API driver and EXTIO
install which makes it much easier to install.
: At the end of the HDSDR "Package" installation, be sure and allow the
HDSDR program to be accessed so the EXTIO part of the installation will
be properly installed (will ask / point you for the right EXTIO version
/ hardware). If this is not done, errors will appear.This is also valid
with the "EXTIO / Driver" standalone version (with no SDR software)
that can be downloaded on the SDRplay website (at the time this text
OPERATION SDR SOFTWARE
The 5 FREE software packages tested for this report were (in order of our ratings) :
1. - HDSDR Version 2.76a
2. - SoDiRa Version 0.100 (Preview's 24, 25 and 27)
3 - SDR# (SDR Sharp) Ver 126.96.36.1991 (1361)
4. - SDRuno Version 1.04
5. - SDR Console V2 tested only
1. - HDSDR (Version 2.76a) *** Top Rated ***
Installed with no problems and easy to use.
EXTIO plug in is required after installation and before use with HDSDR.
Spectrum scope colors (but not easy
to do) and all
of the important adjustments are there and EASY to use and understand.
a nice looking S-Meter, it over reads at default settings however there
is a easy way to calibrate it.
Direct keyboard entry is provided bit a bit confusing to make work just
as with SDR Console (but not bad after adjustment to GUI).
One can adjust to even turn off the waterfall and or spectrum scope (or
change the displayed sizes from default, but is not obvious). Text as
taken from the old Winrad V1.32 manual (which is still useful to get started with HDSDR as it's based on that) :
"The upper window is divided into two
panes, the waterfall and the spectrum. It is possible to choose how to
assign the available space between the two panes by using the right mouse button.
Just place the mouse pointer on the frequency scale. The pointer will
change shape, indicating that you can drag left and right the portion
of the spectrum that is displayed (keeping the left button down) or you can drag up and down (keeping the right button down) the frequency scale which divides the spectrum from the waterfall. Much more complicated to explain than to do…". Just be sure when you adjust this that the receiver is in operation.
If you only desire the Spectrum Display using these adjustments and
then desire the frequency indication ruler on the BOTTOM like I did
(not on the top), then set in Options > Visualization > Swap Spectrum / Waterfall Position . Another important spectrum display user note , by hitting C on the computer keyboard will CENTER the receive frequency.
Features include: Noise Reduction, IF
and RF Noise Blanker, Manual and Automatic Notch Filter, AFC. Excellent
ECSS that holds lock very well and operates on both sidebands or LSB or
USB (selected in a 3 loop cycle by left clicking the mouse on the ECSS
button). ECSS does add bit of bass kick to the audio. Built in recording interface that
records the spectrum or audio (right click on the RED record button to configure). Even includes a scheduler as
well. Sadly it does not offer
FM Stereo but it does have memory storage ("FreqMgr" icon) and quick
band presets. Even can download and import the latest EiBi data.
DRM with the DREAM software (and Virtual Audio Cable,
same as with DSD+) worked quite well in our tests with fairly easy decode. HDSDR has
a DRM mode that presets everything to make it easier. But this offsets
the frequency for some strange reason so we had to move it a bit to make work (tested
with Radio Kuwait on 15540 kHz).
it with DSD+ is mixed bag. Depends greatly on settings as it does with
any of them, but here is a bit more finicky. Appears there is no way to
turn off the FM de-emphasis ?, which could be the reason for
the so-so performance with DSD+ ?
HDSDR uses the least computer
resources to operate out of the lot. If you have an older slower (dual core) computer
that chokes with the others, this is the one you should try. Is really
the ONLY one that will work with the elder Windows XP OS. Overall is a winner for overall use and performance. It’s simple, sounds good, fun and
recommended for anyone starting out using a SDRplay RSP1 (or any SDR).
Great program to get your SDR feet wet and learn the ropes and for general use after.
2. - SoDiRa (Versions .099 and 0.100 (Preview 24, 25 and 27)
Not the most feature packed application (it's not) , but Bernd Reiser's "SoDiRa" does not only decode FM Stereo BUT C-QUAM "AM STEREO"
as well. During skywave nighttime conditions (at the time this text was
added), we received CFCO in Chatham Ontario (Canada) on 630 kHz in
beautiful AM STEREO. This of course would also work in the SW part of
the spectrum for that "pirate" that may show up using AM STEREO (which
has indeed happened over the years). This program requires a EXTIO just as with HDSDR.
It indeed has built in DRM (no separate Dream program required). But
takes a MUCH stronger signal over using HDSDR and Dream in our testing.
In fact its more like useless in North America. Using the Dream
software separately with SoDiRa (with the here VAC of course) also performed MUCH better over it's built in decoder !
Decent ergonomics and logical layout, but as with all SDR GUI's, there
is a learning curve. Decoding has Simple and Universal decoding
selections. No easy volume adjustment on GUI which is a bit of a disappointment. As normal with any of them, FM
"Wide" Broadcast reception takes more computer resources. But overall it's winner again including
it's built in AM STEREO decoding (also has decent selectable sideband Sync
Detector as well). It worked excellent with the separate DSD+
decoder too (in fact the best out of all 5 tested, see more below on this subject).
NOTE : Version .099 (which is included with the 0.100 previews),
was unstable in our tests. Preview 26 was not usable (it blew up right
from launch, but was fixed quickly with Preview 27). Older versions are not archived on the web site.
But overall this is a very easy to use program and we liked it.
Hopefully improvements will continue. A most worthy program, excellent
job Bernd !
3. - SDR# (SDR Sharp)
An older version of SDR# (SDR Sharp)
was tested for this report, version 1361 (188.8.131.521). We were unable
to make any versions above this one to properly work with SDRplay RSP1. An
older EXTIO version 3.7 MUST be used with 1361 (not easily found anymore, contact me if you need it). It is common knowledge
that more current versions of SDR# do not work well with SDRplay RSP1 (if
you can make it work at all).
Worked well enough and enough
adjustments to satisfy most folks, easy to figure out. Not the easiest
to deal with changing frequencies, but has a useful memory window and
that is easy to enter and edit. We found the Spectrum scope not to be
so user friendly or eye pretty (or usable for that matter), but is big and one can turn off the
waterfall. Sadly the SDRplay RSP1 does not work with any of the SDR#’s
extensive plug Ins.
Program has no S-Meter and only very limited color changes possible on the spectrum scope. Works adequately with DSD+ with the
Virtual Audio Cable (more on that later). Even with this working OK
with the SDRplay RSP1 OK, it was not left installed after testing. It does support FM Stereo where HDSDR does not.
4. - SDRuno (Version 1.04)
SDRuno is the mother ship software
and to be fair was still in its early stages as this report was being
typed (version tested 1.04). Installed with no problems and no EXTIO
required. Later versions are reported to be much improved (not tested).
Is made up of various screens that
one must bring EACH ONE up EVERY time the program is accessed. There is
a way around this "multi screen" game by setting up a profile (called
"Workspace's"), but that
still adds a step in the process when accessed every time. Even
with that these screens not attached together (so are all loose on the
desktop), but that can be a plus or a minus depending on user
preference (we did not care for that). But more importantly the general
way of operation makes for a sour
and confusing user experience in our view. One example is where the
selections of the Audio INPUT and OUTPUT sound card device are located.
in 2 totally different spots which makes it extremely difficult to deal
with.....WHY ?? Parts of it were not well thought out and to us is not
It does have the most adjustments of
any program tested in the lot (expect for the spectrum scope). For many this is a huge step forward.
But if you want it simple and easy, this is not the program for you.
Spectrum scope was not impressive or versatile (HDSDR is FAR better). Lack of
adjustments including colors and general tweaks that others do.
Audio issues with the tested version 1.04 in testing. It was not the smoothest
sounding audio out of the lot. General background noises and it’s audio sounded muffled and
weird at default settings (including being grizzly and harsh under certain situations, but not
always), at least with our 4 test computers. Was
clearly on the bottom of our “desirability” list.
Version 1.04 was NOT
usable with DSD+ in the testing period (more later in this report).
Started to sort of work, but it was a "no go" for us. Perhaps later
versions work better (not tested) ?
5. - SDR Console (V2) *** Program Good , But Bottom Rated Because of Expiring Scheme ***
Was the easiest to use and most
appealing GUI. Easy to install and to get up and
running. No other software (EXTIO) was required for operation aside
from the API driver.
SDR console V2 at the lower spectrum
bandwidths were most usable provided nothing else was running in the
background with a lesser computer. In fact it was the second runner up
for using the least computer resources to operate. Supports FM stereo plus RDS.
Memory operation (V2) was
straightforward and useful, however direct frequency entry was quirky /
difficult and sometimes locked up the program. Important tip :
Be and enter the proper leading zero’s. Features
include: Noise Reduction, Noise Blanker, Manual and Automatic Notch
Sideband AND LSB / USB "Synchronous Detection / ECSS" which holds lock
well. Excellent AGC (Fast-Med-Slow) with adjustments. "Span"
adjustments were first rate.
A huge downside and the reason it was BOTTOM rated, as this report was being complied
, “SDR Console” uses an expiring license scheme. So whatever version you are using it turns into pumpkin
sooner or later. Not a good scenario here in our view (in fact totally unacceptable).
*** Dynamic Range / Sensitivity and General Performance ***
To make matters more fair we compared
sensitivity using a standalone Yaesu VR-5000 wideband receiver. For my review on the Yaesu VR-5000 (click here).
Testing (ears method) here was done
only with SDR Console V2 at default settings (which we found out are
the best settings to use) :
- LNA (OFF)
- RF Gain at –50db
(other settings in the Mirics API also at Default)
Antenna’s Used (for both receivers) :
- SW/HF Outdoor Antenna : 55 foot RF Systems MLB (long wire)
- VHF/UHF Outdoor Antenna (above 30 MHz) : 19 inch ground plane at 25 feet height.
Dynamic Range : While tuning the
ShortWave / HF bands “Dynamic range” (overloading) was never
experienced during the testing period with the SDRplay RSP. It behaved
itself very well even in the 49 Meter band at night. No FM Broadcast overloading either.
Receiver Noise : SDRplay RSP1 was the overall winner here. But in some areas the Yaesu actually won the battle.
Selectivity : Of course the SDRplay RSP1 blew away the Yaesu VR-5000 here , no real comparisons required.
***** Sensitivity Winners (as compared to the long discontinued Yaesu VR-5000) *****
(very weak signals and audio recovery, mode and bandwidth setting changed as required) :
MW / AM Broadcast : Yaesu VR-5000 (SDRplay RSP1 was OK on MW , but the
VR-5000 was the clear winner even with it’s attenuator on)
- SW 11 Mhz : SDRplay RSP1 (by a
hair). Signals were about equal, but the lower noise floor made
recovered audio from the SDRplay wins easy here, especially with the
Sync Detector on.
FM Broadcast 93 MHz : Equal. Perhaps a very slight edge to the
SDRplay RSP1. But it’s pretty much an even showing here.
- 162 MHz : Yaesu VR-5000.
Audio was heard better from the Yaesu here for some reason, but a near
equal signal on SDRplay was present. Another close one.- 450 MHz : Near Equal. S/N goes to the SDRplay here.
In general it’s a very sensitive
device, just as much as the elder Yaesu VR-5000. Of course the overall
performance edge has to go to the computer connected SDRplay RSP1. But
the elder Yaesu VR-5000 held it’s own. The Sync Detector with SDR
Console works fantastic. Double sideband ECSS or just LSB or USB
selections. Holds lock with even signals that are near into the noise.
*** Image Issues / Center DC Spike ***
Some users have reported FM Broadcast
signals bleeding into other parts of the tuned spectrum with the
SDRplay RSP1. We did not experience any of this in our testing. Any
signals were also absent at the test location. Please note, we do not
live in a large metro area with excessive broadcast signal levels.
One bug we did experience was the
well-known DC spike issue. That is one sees/hears a low level carrier
always in the dead middle of the spectrum scope no matter where it’s
tuned. With some software (HDSDR and SDRuno) there is a way to deal
with that (not tested). This bug varies as it’s related to the sound
device (or sound card) in the host computer. Some may never see this
*** USB Cable Chokes “To Be Or Not To Be ?” ***
The SDRplay folk’s recommend that a
USB cable that has chokes on either end be used to help keep radio
In our testing we could tell no
difference with more or less
interference (using outdoor antennas with coax feed line) using a USB cable with and without the ferrite chokes . This was with a laptop computer or Desktop, cable
length under 6 feet. Using with any indoor antenna, this could be a different story ?
But of course this will depend on
YOUR situation and no 2 are going to be the same. As they say the
shorter the USB cable the better. I would say better quality cable 6 feet (around 2 meters)
or less length.
*** DSD+ Program (see our set up information on the bottom of this page)***
OK….we try and only cover Short Wave
/ HF part of the radio spectrum here with any reviews, but in this case
we just had to try and make work the DSD+ program with the SDRplay RSP1.
DSD+ is a popular Windows Computer software
used for decoding digital speech such as P25 with SDR
receivers. With the tested version 1.101, includes an event log that
shows call target and source ID history and an audio waveform screen,
which can help determine if DSD+ is receiving audio correctly (a very
useful feature as we found out). Has the ability to decode the
following digital modes (and is automatic too). Please make note the
DLL's are downloaded separate and when unzipped are placed into the
same directly as the program files.
• DMR / MotoTRBO
• P25 Phase 1
It can be used as stand alone program
as well. In other words one can take a stand-alone scanner receiver,
tap the discriminator audio output and feed that into the computer
(line and or Mic input jacks). But in our case we desired to use the
same computer that hosts the SDRplay RSP with the DSD+ program. To do
that the use of a Virtual Audio Cable (VAC) is required. We used a FREE
After installation of the VAC and
with certain adjustments and procedure (whew!!), it performed
adequately. Not as stable and clean P25 as a standalone scanner, but
was very usable especially with "SoDiRa" program. This program
decodes digital modes that are not covered on most standalone scanners
as well. Trunking is not normally possible with only "one" SDR receiver. Success
depended on the software used as well as careful adjustments
(especially when using HDSDR). Some were better than others with decode
quality and stability.
That is the stinker with making DSD+
to work with the SDRplay RSP1, frustrations and hours in the battle of
setting it up. Provided below are my
PERSONAL notes what I did to make it function. This of course it cannot
cover everyone’s situation (computers, sound cards etc), so treat this
only as a base. Some parts may be more my feelings and not facts.
Please keep in mind these tests were
done using a Windows 7 “DUAL Core 3 Ghz” computer with 4 GB of memory.
Your experiences may vary and could (should) work better with a more
zippy and QUAD core processor computer? More memory does not hurt
either (say 8GB). Again when using the SDRplay RSP (and especially
with DSD+ in the mix) with a lesser computer one should not have ANY
other applications running. Otherwise expect decode dropouts and other
nastiness with any of them.
IMPORTANT NOTES : Of course
use FM wide mode (with no filtering) at around 15~20 kHz bandwidth for
most digital modes. Setting of the VAC audio level is extremely
important. If it's too loud or too soft, decoding will be choppy or
even not at all. So watch your audio level (metering bar on the VAC in
the Audio Properties).
So the preference list for the best program using DSD+ with the SDRplay RSP1 :
1. SoDiRa. Works the best “bar none” with DSD+.
2. SDR Console (V2 or V3). Second best with DSD+.
3. SDR# (SDR Sharp). Not too shabby. But not as stable or clean as SDR Console. A drop out once in while.
4. HDSDR. Works but more dropouts than with SDR# (usable).
5. SDRUno. Plain and simply unusable.
Maybe a stream of good decoding and then back to near nothing. (Yes the FM filtering
was turned off).
*** Final Word ***
The SDRplay RSP1 is clearly the
winner in its price point for a REAL SDR. Gives for greatly increased
performance when compared to those under $ 50. RTL-Dongles that we see
sold all over the place at time this report was compiled. The model was replaced in late 2017 by the RSP1A model (not tested) that includes more front end filtering, 0.5 PPM TCXO and a 14 bit ADC.
© N9EWO, all rights reserved
: I will NOT be held responsible for any information that
is listed here.
ALL DONE AT YOUR OWN RISK !
Set Up with WINDOWS 7 (64 or 32 bit) Computer (NOTE : These are
MY suggestions/notes ONLY and your situation may be different).
(set up after all SDR Software / Driver is installed, including "after" the VAC)
VAC - Virutal Audio Cable (required)
VBCABLE A and VBCABLE B are just 2 different channel cables
(does not matter which one you use for the SDR PLAY and DSD+)
AUDIO DEVICES ON HOST COMPUTER SET UP (with RealTek Audio Driver)
(Right Click "white speaker" in lower right hand corner)
Computer: Playback Devices
Speakers - Selected for the normal speaker Default Device.
Cable VAC - (active) must be ready
but is not set at default device but will show it’s VU meter when
properly in use. Use the "Set Default" on the bottom to do this.
Computer: Recording Devices
Cable VAC Output – Default Device (will show VU level bar activity when properly in use)
Stereo Mix - Ready (active) but not at default.
SDR SOFTWARE SETTINGS
NOTES : Be Sure the Computer
Settings above have been made BEFORE the Software ones below are made.
Also when any of these settings are changed be sure and shut the
program down and restart (otherwise it may not take). Do not start DSD+
until all is done.
**** HDSDR **** (Watch Excessive IF Gain and ADC Settings)
Sound Card Selection
RX INPUT (From Radio)
RX OUTPUT (To Speaker)
Sound Card Selection
1: CABLE A Input (VB-Audio Cable A (or B if that one was installed)
(Volume Control on HDSDR Interface USUALLY set at or near 100%, volume controlled with normal computer slider)
CPU Load with HDSDR and DSD+ P25 Decode (nothing else), Intel Dual Core 3.0 Ghz 4GB memory : Approx 55~65 %)
Watch out for excessive IF Gain and ADC Settings.
*** SoDiRa 0.100 Preview 25 and 27 **** BEST PROGRAM TO USE WITH DSD+ IN TESTING (and sounds the best) *****
Demod/Decoding (Drop Down Box) :
Select : Universal
RF/IF Audio Option :
- Un-check Audio Bandwidth Filter
- Be Sure that Audio Out (DAC) does not go into red.
In Configuration :
Wave Device Tab select (using VAC A):
INPUT : "Cable A Output (VB-Audio Cable)"
OUTPUT : " "Cable A Input (VB-Audio Cable A)"
In Demod/Decoding :
Demod Type : FM
SideBand : DSB
Demodulation Bandwidth : 20 kHz
*** SDRuno ver 1.04 ***** NOT USABLE *****
DSD+ Does not function properly With SDRuno (1.04)
*** SDR# (SDR Sharp) **** version 184.108.40.2061 ONLY *****
Works OK with DSD+ but not as good as SoDiRa.
Note : Later versions do not work properly with SDR PLay
In Audio Drop Down "OUTPUT" : MME Vitural Audio Cable (Input can not be adjusted,is grayed out)
Be sure and un-check "Filter Audio" (this MUST be done)
REGULAR DSD+ OPERATION PROCEDURE ** MAY NOT WORK PROPERLY IF NOT FOLLOWED **
1. Plug in SDR Play to computer and antenna.
2. Activate SDR Program (Do NOT "Start" it Yet), be sure frequency and mode is set properly.
3. Activate DSD+ Program (DSDPLUS.exe)
4. Be sure volume slider on SDR
program is set at 100% (as all others including the VAC ones, expect
for the regular speaker output volume control)
5. Hit "Start" (or Run) SDR Program.
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