This LNA was discussed in an earlier thread and I decided to see how it might work with a home brew loop. https://www.amazon.com/gp/product/B01N2NJSGV/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1
I spent a total of $25.88 for parts. I had the PVC pipe for support and coax cable in the junk box. This little LNA connected to a loop made from 14' of coax and powered with a 9vdc battery is providing signals from 5KHz to ???, well at least 30MHz for the KiwiSDR. It has been tested, but is not currently online as I'm working to "ruggedize" the LNA in a small pipe.
I think an inexpensive antenna such as this could improve some KiwiSDR installations. It isn't perfect and displays more repeating interference spikes than I would like, but it is still better than many other antennas I've listened to. Not quite as good as the W6LVP but it is better below 500KHz and probably equal up to 18MHz. It needs more comparison testing and the loop circumference might make a difference.