For the SDRplay we used a beta version of their SDR# 1400+ plugin for their latest API which fixed most of the RSP's imaging problems. It was a beta released just to us to do this review sooner so it was a little buggy in terms of crashes, but we stress that this is not the case for the officially released plugins. SDRplay recommend using their ExtIO plugin instead, but to get fair comparison screenshots we wanted to use the same SDR# version on both Airspy and RSP tests. To be sure the plugin wasn't affecting RX results we compared it to their officially released ExtIO plugin for older versions of SDR# and HDSDR and we saw no changes in terms of signal performance.

ADC - Analogue to digital converter. The main component in an SDR. It samples an analogue signal and turns it into digital bits. The higher the bit size of the ADC the more accurate it can be when sampling. Software - The hardware is only half of an SDR. The software the unit is compatible with can make or break an SDRs usefulness. The USB B connector on the RSP is sturdy and does not easily come loose. It is also easier to find high quality shielded USB cables with USB B connectors. Images/Aliasing - Bad SDRs are more likely to overload and show images of strong signals at frequencies that they should not be at. This can be fixed with filtering or by using a higher dynamic range/higher bit receiver.I decide not to use this device as the users may create all kind of input conditions using wires, long antennas, open, short etc. and this device can not handle all that on such a wide range of frequencies. The RSP worked fine on all the PCs that we tried on (all i5 and i7's mentioned above) and it ran well at the highest rate of 8 MHz. Center DC Spike - A good SDR should have the I/Q parts balanced so that there is no DC spike in the center. More importantly, the spectrum captured is not continuous, and [Oleg] questions whether it can be demodulated properly. He had to resort to frequency overlaps due to upsampling, and he’s not quite sure how to compensate for that. Overall frequency stability is also in question. However, from here, seems like most of the work towards building a wideband receiver is done!

It seems that the design approach of the Airspy is to optimize for signal linearity and to avoid overloading through natural high dynamic range. If you prefer to use the automatic gain control (AGC) then you can control the "setpoint" value which will try and keep the noise floor at the specified value. Compatible with SDR#, HDSDR and SDR-Console through plugins. Though compatibility with SDR# is restricted as third party plugins cannot be used. The RSP is also compatible with any app supporting ExtIO. For example: I can recognise a lot of efforts to perform such a detailed test and to write the article but unfortunatelly this test can not bring the real light on the performance of the tested equiment simply because of the method used to perform the comparison. I will not judge about the tested receivers performance, I will try to point out some wrong statements written about the equipment I made (LNA4ALL). Bandwidth - A larger bandwidth means more signals on the screen at once, and more software decimation (better SNR). The downside is that greater CPU power is needed for higher bandwidths.

Part 2: How to Fake Android GPS with a HackRF?

Adam describes the situation very well and believe me it is not a coincidence that a lot of preamps, e.g. for active ADS-B antennas that need a very low noise figure while having a great dynamic range magically are all being distributed with the same MMIC as the LNA4ALL and not the PGA-103+ which just looks much better on the paper. You can be sure that Adam would use the chip if it would be stable, since it is cheaper than the PSA4-5043+ and as mentioned offers less noise while having more dynamic range. Frequency Stability - We should expect the receiver to stay on frequency and not drift when the temperature changes. To achieve this a TCXO or similar stable oscillator should be used.

Initially when writing this review we had deep problems with the imaging of strong signals on the RSP. However, a recent Dec 22 update to the drivers has fixed this imaging problem tremendously. From online reports it seems to run fine on older PC's like Core2Duos, though the maximum sample rate may be restricted. There is also the option to toggle on or off the internal Mirics chip LNA. This is the LNA in the tuner chip, and not the front end LNA which is always on for VHF+ frequencies. Turning this LNA on can help to reduce the noise floor, but also may cause additional imaging problems. I have 40+ years experience as a ham, SWL, scanner enthusiast, satellite enthusiast so I know what I am talking about.

These are ballpark figures merely arrived at by reading off the peak signal strength for the main signal and comparing it top the peak signal strength of the image as shown on the SDR#. Products that weigh more than 0.5 KG may cost more than what's shown (for example, test equipment, machines, >500mL liquids, etc).

Step 3: Now, you need to generate your GPS-simulated "BIN" file for GPS spoofing, and for that, you need the coordinates of the location you want to simulate. Open a map app, find the location you want to spoof, and copy its coordinates. Best results are from judicious use of the LNA slider and the internal amp. Did not use the VGA slider as am not sure of it's role in receiving. These are just very rough guesses and they could be wildly inaccurate. Note that these costs are for parts only, and they do not take into account manufacturing costs, engineering time costs and support staff overhead costs etc. Airspy RF Design - The overall design of the system. For example, how many lossy components such as switches are used in the RF path. As the design complexity increases usually more components are added to the RF path which can reduce RX performance. Installation involves simply plugging the Airspy into the USB port of the PC and letting Windows plug and play automatically install the drivers. The user can then open up SDR#, select Airspy from the menu and push start.Connect your Android phone to your computer and launch the Dr.Fone app. Next, tap on "Virtual Location" and press "Get Started" on the next screen to initiate the process. Now, find your location on the map by pressing the "Center On" icon.