The magic ingredient is the software on the raspberry pi, rtl_hpsdr written by N1GP, which makes up to 7 RTL devices look like a Hermes receiver. This then in turns allows skimmer server to be used which is optimised for multiband and low cpu usage. It runs with almost no cpu utilitistion in a virtualised Windows 10 environment, covering 192khz on 40m.
Seems to work, though I seem 15-20dB off VK4CT with the loop. Still working on calibrating it and ensuring it’s stable, though so far it looks good.
I also have a direct sampling RTL kit to finish to perform comparisons and the run two bands at once.
Another neat thing is with another dll, I might be able to run a websdr at the same time. Probably easier and better just to buy an elan receiver, but this is fun.