|  
              Igor VE3KAO 
               When 
                I served in the Soviet Army I had contact with a military radio 
                station that was used such Underground Antennas. The station was 
                from Sverdlovsk (now Ekaterinburg). My station 
                was near Moscow. 
                (I.G.: Distance Moscow- Sverdlovsk is 1800 km.) We used band 3.0- 6.0- MHz at the winter and 4.0- 8.0- MHz at the 
                summer. The station with Underground Antennas was heard by S5- 
                S6. When the station was used the usual stationary antennas it 
                came to us by S9+.  
              I 
              asked the chief of the radio- center about the Underground antennas. 
              He told me that he saw how the antennas were installed. It was thick 
              coaxial cable that was buried in trenches in 2.5- 3.0- meter depth... | 
             
              yl2gl  
                 
              The 
                Underground Antennas were at the receiving radio- center where 
                I was served (in the Soviet Army). There were symmetrical antennas. 
                The antennas were reserved ones that supposed to be used at emergency 
                situation (at nuclear war)...  
               
              UA9FBQ 
                 
               I 
              took part at installation of the Underground Antenna.. It was coaxial 
              cable (looks like) near 10-cm in diameter. The coaxial cable was 
              buried on 50-cm into the ground. I used the antenna with a transmitter 
              "OKUN". 
              The antenna matched well but the efficiency was low. The antenna 
              was tested up to 6- MHz. 
               
             |