So far my HF upconverter and rtl-srd dongle works very well down to 160m but drops off below 1800khz. Today I noticed the seller offers a upconverter for ELF-HF so I ordered one, it takes a while to get here from Hungary. I will try to update this topic after a evaluation is made. Does any one use SDR for ELF,LF ? My Kenwood R2000 only goes down to about 130k, am able to pickup AM stations from Europe in the winter, it's interesting but would like to be able to pickup ELF signals/beacons.