New Demo of the Upcoming Spyverter Upconverter
The Spyverter is a new high performance upconverter that is being developed by the team behind the Airspy software defined radio and the SDR# software. It is designed to be used together with the Airspy, but it should also be compatible with other SDRs as well. The main claimed advantages over other upconverters will be it’s low loss and high IIP3 performance, which means that the Spyverter will not saturate in the presence of strong signals as easily as other upconverters.
Recently W9RAN, who is involved in the design and testing of the Spyverter uploaded some demo videos of the Spyverter + Airspy combo in action. The first video shows how the Spyverter when used together with the Airspy and SDR# allows for seamless tuning between VLF, HF through to VHF/UHF (no need to set any offsets).
The next video shows the Spyverter + Airspy combo working during a RTTY contest on 40M with very densely packed signals, some of which were very strong.
W9RAN (ranickel on YouTube) also has additional Spyverter + Airspy videos on YouTube for viewing if you are interested.
I think the characterization of high IP3 on the output signal is incorrect. IP3 is not related to saturation directly (that’s more like the compression point), rather it says that nonlinear, 3rd-order products of the input will be far below the linear output level. This means you can operate the upconverter closer to saturation (where you often get better power efficiency) without worrying as much about spectral regrowth (possibly violating your transmit mask).
Correct. IP3 is all about linearity.
From the front page of the Airspy.com:website:
NF better than 8dB
IIP3 > +30dBm
Minimum RF Input: 1 kHz
Maximum RF Input: 60 MHz
IF frequency: 120 – 180 MHz
Phase noise at 10kHz: -122 dBc/Hz
I suspect that the use of IP3 is correct, for this particular hardware. Because of the knowledge and experience of the people behind SDRsharp and the Airspy, it is exceedingly unlikely that they would use this term if it did not apply.