I waited until the first impressions were available, then decided to go in for two RSP-2 units, which I received the first week of February. One of the very attractive claims [for me, anyway] with SDRplay's software, SDRuno, is that it is "designed to run multiple instances" on a single system, and each instance of SDruno can support a separate RSP-1/2/2Pro unit - making a great deal of spectrum concurrently available on a single computer.
At this point I have engaged in approximately 8 weeks of testing of the RSP2 units with both Windows and Linux systems, and clocked over 2000 device-hours between the two RSP-2 units purchased. Here are my observations --
Overall, I am not disappointed with the hardware or software - performance was equal to or above that of many analog receivers in the $500 ~ $1000 range. I did not experience any serious RFI issues via conduction on the USB cable (as I expected I would) and typical application of Mix #77 (Amidon FB-77-1024) beads was sufficient to eliminate what little conducted noise was observed.
After opening one of the RSP2 units up, I can say that everything with the circuit-boards and construction look very well done - nice "tight" RF paths throughout the front end, plenty of groundplane under and around the chips and RF paths as appropriate, no "hot spots" evident in operation, and more than sufficient vias between layers to ensure consistent front-end operation across the frequency range specified.
IMHO, the MW filter doesn't cut the BC racket sufficiently, but my expectations in this regard are high: per my testing, it does *exceed* the advertised ">=-30dB signal reduction in the 680~1550KHz range", and holds close to -30dB across the entire North American AMBC band, 535~1715KHz - and no intermod or digitization artifacts are evident so long as you are looking at/listening to spectrum above 1.8MHz.
However, when seeking to receive *below* 525KHz, I found additional filtering of the MW broadcast segment necessary to eliminate residual intermod and digitization artifacts which were otherwise rather pervasive between 90~450KHz while using various antennas, including the PA0RDT E-Probe, as well as various loops/pennants [both amplified and passive], and "long wires" in the 250' to 1200' category with appropriate UN-UN transformers to present a ~50 ohm impedance to the RSP-2's RF input port across the spectra of interest.
Let me qualify my previous statement: I own a rural property where the noise floor is very low - in the -151dBm range - and have invested a lot of time and effort to provision that property with antennas dedicated to VLF~MF reception. In that environment, I have found the limits of my Drake R-8, TenTec RX320, Palstar R30A, Icom PCR-1500 and R-75, and numerous other receivers, in addition to the issues I note above with the RSP-2, so please do not take my comments as specifically prejudicial to the RSP-2.
If the noise floor in the VLF~MF spectrum at your location is only in the -120~135 dBm range, as is typical for a suburban neighborhood then you probably won't ever encounter the issues which I have with the performance at LF.
Of particular note is the fact that the MW filter of the RSP-2 cannot be enabled for use with the HiZ antenna port on the RSP-2/2Pro [neither can the FMBC filter, but that is of less interest/concern to me].
This fact was not obvious in their marketing sheet, but should be made so - as it represents a notable limitation of the RSP-2 for those interested in MF and LF reception.
OK, enough about LF. The RSP-2's performance between 2MHz and 500MHz was just plain outstanding. HF sensitivity was below 1.0 uV under typical conditions. In all of my HF and VHF testing, the units consistently demonstrated < 2.5uV sensitivity to weak signals, even when very strong signals (typically SWBC or VHF 2Way base-stations) were between 10 and 1,000Khz away. For use above 500MHz, I'm not the guy whose opinion you want - weak-signal UHF and microwave just isn't my thing.
The SDRuno software (ver 1.1.12) is generally well behaved, straight forward, and easy to use, albeit a bit resource hungry on the host computer. I will note that there were occasional glitches with the individual "Virtual Receiver" and spectrum windows when I had several [between 4 and 10] open concurrently. This was evident whether the "Virtual Receivers" were associated with one or multiple RSP-2 units, so the issue is *not* related to operating multiple instances of the SDRuno software.
With these glitches, the particular "Virtual Receiver" windows either froze, or displayed incorrect numeric frequency and spectra for the selected "Virtual Receiver" in question. Closing and Restarting the [Main] SDRuno window resolved the issues temporarily, and I suspect there is a memory leak specifically in the "Virtual Receiver" code itself, because the glitching becomes more pervasive as time goes on [if allowed to] These glitches were sometimes evident after as little as one hour of operation, and were always evident after 18~24 hours of continuous operation. Normally I did not observe this until either 1) I had many virtual receivers running,or 2) the software had been running for many hours; but I was testing on a very well provisioned system (Dual Quad-Core Intel 2.66GHz with 8GB of RAM and an SSD system drive (so very fast page-swapping of memory, when required) - on lesser systems, the suspected memory leak may become apparent while subject to less demanding usage than that which I engaged in, but this is pure hypothesis, not observed behavior.
The API offered with the RSP2 is excellent. It has it's own well designed control panel to manage hardware specific aspects of the RSP2 unit(s); and interfaced well with both HD-SDR on Windows, and Soapy on Linux in my testing.
So, two months and many hours later, I'm definitely not sending my RSP2 units back. Since I have to bring a laptop "out to the farm" for QRSS, WSPR/JT9, & etc, it's nice to have the RF hardware fit into the laptop bag too. It used to require several trips from the car to the shack to get all the equipment on the bench and setup...now I can walk in the door and get to the point of "pick a band, any band" in about 2 minutes. The only thing I miss is the smooth-spinning frequency control knob... but I could probably buy a nice USB optical encoder Dial if I really wanted one badly enough.
Cheers,
Chuck
N1KGY