Photo: Modified Russian home brew FULL QSK UW3DI-III HF Transceiver.
The legendary and very famous HF transceiver was designed in the Soviet Union by Radio Amateur – Yuri Kudryavtsev (UW3DI) in 1968. The transceiver has been build on radio tubes. Latter his second version came on semiconductors (UW3DI-II). Since then the transceiver has been repeatedly replicated and improved / modified in the parameters by many radio amateurs. A third and even fourth (FULL QSK) version, has been converted in late 1980’s. The transceiver has been relatively simple to use, and served as its widespread popularity among amateurs of the Soviet Union and beyond. The radio amateurs called this gear just simply – “DEI” (short from UW3DI).