Extracts from Russian radio magazines including what I think is The Kovalsky theremin.
These were extracted from articles I found via links I found at Theremin World
These scanned files of Russian radio magizines:
You can view these complete files with this free software: http://blog.kowalczyk.info/software/sumatrapdf/download-free-pdf-viewer.html
I cannot read Russian, and am not sure that I have actually extracted all theremin related stuff from these articles -
Anyone having better insight into this stuff, PLEASE add a document here to complete the information!