Keywords: Antenna location at the US Naval Communication Station Harold E. Holt in Exmouth, Western Australia, 1972.png Antenna location at the U S Naval Communication Station Harold E Holt in Exmouth Western Australia in 1972 This is a very low frequency VLF transmitter which communicates with submerged submarines This type of antenna is called a Trideco or umbrella antenna It consists of multiple steel masts which radiate radio waves with a network of cables attached to their tops The cables do not themselves radiate radio waves but serve as a capacitive top-load adding capacitance to the top of the antenna to make it more efficient On the ground under the antenna there is an elaborate ground system called a counterpoise consisting of radial cables in a star shape suspended a few feet above the ground NAVELEX 0101 113 Fig 3-14 1972 US Navy Naval Electronics Systems Command PD-USGov-Military-Navy Original upload log en wikipedia NAVELEX0101-113 2CFig3-14 png wikitable - 2011-04-01 17 26 1379×954× 320560 bytes Mcg410 <nowiki> Diagram of Antennas at NCS Harold E Holt NAVELEX 0101 113 Fig 3-14 1972 US Navy Naval Electronics Systems Command </nowiki> U S Naval Communication Station Harold E Holt Exmouth Western Australia |