LZ1DX 1956 Bulgaria
Bulgaria did not allow private ownership of transmitter until after WWII.
LZ1DX Dimiter Sibirsky was one of the big DXers in Europe with 263 countries confirmed in 1958. Sibi worked CW, AM, SSB.
QSL from the estate of W5KC
Courtesy of W5KNE
Photo from Don Chesser W4KVX DX Bulletin #47, Oct. 14, 1958