SDR ⁽³⁾

I now have a second YouLoop (supplied by Moonraker) set up in the loft, this time connected to the RSPdx which itself is connected to the Linux PC. I use SDR++ on the Mac and am getting used to the excellent software (see https://www.sdrpp.org). There are versions specifically for Ubuntu, Windows, MacOS (Intel and Apple silicon) and the Raspberry Pi, plus the source code is available to compile yourself. So I wanted to compare the Airspy HF+ Discovery and the RSPdx. When installed on the Linux PC SDR++ does not see the RSPdx. However, once the relevant API is installed and running it duly appears in the devices list as SDRplay and displays the necesary antenna selection menu. So here they both are, looking from 0 to around 85kHz. First the Mac and Airspy: And the Linux PC and RSPdx: This is about as clean as I managed to get the various settings and it is particularly useful having the same software on each machine. Of course this is a rather arbitrary comparison given the multitude of settings and the fact that they are on two different platforms, plus the two YouLoops are facing in different directions. But it does…

Just recently I realised that amongst my kit I do not have a scanner other than the baby IC-R2. So I had a look to see what there is and they range from cheap but limited range ones that do not have a continuous coverage to expensive types that are just way over the top for my needs. My interest is limited to having something I can quickly switch on and listen to a few spot frequencies, including amateur radio ones and the local airport ATIS. I also have a bunch of various SDRs but none met the 'quickly switch on' requirement. Time to fiddle then. Other than the various Raspberry Pi systems the only always-on system I have is a Mac Mini. The other two desktops - Linux and Windows - only get turned on when I want to use the FT450D or TS2000X on digimodes or I need more screen real estate for something. So what can I do with the Mac? I already had CubicSDR loaded and I downloaded the Mac version of gqrx. As I use SDR# on Windows and after reading some blog posts I found and downloaded sdrpp. I already have the Airspy HF+…

I now have two new toys, an Airspy HF+ Discovery SDR, and an Airspy YouLoop antenna. Plus I already have a SDRplay RSPdx which was purchased some time ago. The initial aim of these is to hopefully receive signals from SAQ’s 100 year anniversary broadcast. The YouLoop is in the loft and connected to some RG213 coax back to the shack. That coax was feeding the random wire for HF but as I now use the external wire the coax was pulled back and shortened. It is entirely passive so does not require any voltage supply and has a range of 10kHz to 30MHz plus VHF up to 300MHz. There is also an IP35 mini whip which was acquired some years ago and as an active device needs a supply which is achieved by a bias-tee fed from the 12V shack PSU. That antenna has a range of 10kHz to 30MHz and is fed via some RG58. The YouLoop is pointing, quite by chance at the MSF 60kHz time signal transmitter. The IP35 is largely omnidirectional. The Airspy covers 0.5kHz to 31MHz and 64MHz to 260MHz whereas the RSPdx covers 1kHz to 2GHz with no gaps (200MHz on the BNC…