Dragging up an old thread. SDR's are cheap nowdays, the RTLSDR Blog V3 is available from SEComms
https://secomms.com.au/product/rtl-s...-radio-dongle/
There are eBay sellers offering the same but having tested the ebay variants it's apparent that they are copies and the perfromance is nowhere near as good as the item from SEcomms. I use various SDRs including the above listed USB dongle, the performance of the RTLSDR BlogV3 is close to anything on the market and at a cost of $45 they're a bargain. You need software to drive them, I use SDR Console, once configured they will receive from longwave bands right to microwave in all modes.