LF/VLF
CASE HISTORIES

CEC has been installing fixed-station LF & VLF transmission systems since the 1960s. Simply put, no one has deployed as many systems, or has more experience developing, manufacturing, and upgrading fixed-station LF & VLF transmission systems than CEC.

Continental was selected as subcontractor by Larsen and Toubro (L&T) to provide its experience and expertise in the design and manufacture of VLF systems to support the INS (India Navy Ships) project.

The project, commissioned in 2014, required CEC to supply VLF transmission equipment for submarine communications.
CEC manufactured, delivered, and installed the Type 124 VLF Solid State Transmitter capable of delivering 6MVA. This transmitter is believed to be the highest power solid state transmitter operating in the world.
Continental delivered a state-of-the-art VLF system which included the transmitter (30 SSPA’s), a control system, ATUs, Component Sourcing, Transmission Line, Loads, and Switches as well as the RF Design of the Antenna.
The antenna system consists of two 470m slant-feed top-loaded monopole antennas with ground mast. CEC’s expertise lead to satisfy the project’s requirement of increased data capacity up to 400 baud.
Continental is proud to be part of a team that delivers advanced communication capability in support of India Navy Ships.

US Navy VLF Installations

Very Low Frequency (VLF) communications transmitters use digital signals to communicate with submerged submarines on at frequencies of 3-30 kHz. The Navy shore VLF/LF transmitter facilities transmit a 50 baud submarine command and control broadcast which is the backbone of the submarine broadcast system. The VLF/LF radio broadcast provides robustness (i.e., improved performance in atmospheric noise), availability, global coverage, and has seawater penetrating properties.
lualualei, Hawaii (USA) AN/FRT-64
VLF transmission system operating under the call sign NPM
on 21.4 kHz and 23.4 kHz
Exmouth, Western Australia AN/FRT-67
1 MW VLF transmission system operating with the call sign NWC
on 19.8 kHz
Jim Creek, Washington (USA) AN/FRT-3
1.5 MW VLF transmission system operating with the call sign NLK
on 24.8 kHz
Cutler, Maine (USA) AN/FRT-31
1.8 MW VLF transmission system operating with the call sign NAA
on 24.0 kHz