High performance SDR choices
I am no expert by any stretch of the imagination. I picked up an airspy because I enjoy what the DVB dongles can do and recognized what the designer intended to do with the tuner chip. I looked at it as a dongle on steroids, and wanted in. I knew that the dongles were slapped together and used the cheapest of components, and if they worked so well than something designed especially for SDR using quality components would be for me. The airspy is set up to do so much more than I can even comprehend, but I only want to simply search and receive signals.
The performance has been terrific. It is nice to sniff around without so many images and a nice smooth noise floor.
I have found the sensitivity to be very good, the selectivity good when the proper bandwidth is set. The ability to adjust for gain and other parameters allows much flexibility in dialing any given signal.
I truly feel this is only the beginning of what can be done with SDR depending on where the skilled software writers take things and I think the airspy will be not only capable but affordable.
It is also good to know that the designer is here now on the forums.
Although I am not familiar with all of the options for receivers I would recommend airspy to anyone who wants to go a step beyond the DVB dongle for a more quality experience. Some have questioned the cost, I don't know the profit margin on each unit but if development continues and improvements/upgrades keep coming with software than I do not mind putting a little coin in the pockets of those that brought the airspy.
As well as the devices mentioned in this thread, there is also the SDRplay RSP at $149 where we see reviews like this:
"...for LW-SW reception I use a home-made pa0rdt-Mini-Whip antenna (50kHz-30MHz) in combination with a home-made tunable preamplifier.
For FM – 2m I use a modified telescope antenna. I also have RTL-SDR sticks with up converter and an old Kenwood R1000
receiver. For SDR I use both, HDSDR and SDR# software.
The first thing I noticed is that the SDRplay RSP works well below the specified low frequency limit of 100kHz. For example, the time
signal at 77,5 kHz is well received. The lower limit in frequency for practical use seems at approx. 50kHz.
That was a good start. However, the extremely high sensitivity really knocked me off my feet: Stations which are noisy on the R1000 (so
far my unbeatable workhorse) are crisp and clear in the RSP, thanks to the innovative LNA concept. Furthermore, I could receive week
stations even in between strong signals – of course somewhat noisy. But in the R1000 they are completely buried within the noise and
you would not have guessed that there is something. That also holds for FM and 2m: the RTL-SDRs are much, much worse, even when
using an external LNA.
The next positive impression was on frequency accuracy and stability. The displayed absolute frequency appears accurate within less
than 100Hz for my RSP. Besides accuracy, frequency stability is the key– otherwise any fixed ppm-corrections are useless. For my RSP I
could detect no frequency drift e.g. within a few hours of receiving SSB/CW or when tuning in the next day. In complete contrast to all the
RTL-SDR sticks I have tested – they drift like hell.
Another positive observation is the low heat generation of the RSP (– no comparison to the RTL-SDR sticks). Maybe this also contributes
to the good frequency stability of the RSP.
What is left to say: Congratulations to the SDRplay engineers who have developed this superb piece of SDR hardware! It is worth every
penny.“ , June 19th 2015
more candid reviews are on
https://www.facebook.com/groups/sdrplay