VLF Communications

The ability of VLF and LF radio transmissions to penetrate seawater allows submerged submarines to receive strategic and tactical communications. Drumgrange has been actively involved in the UK VLF Submarine Broadcast Strategic Communications programme since the 1980s having developed bespoke items of equipment that span the entire VLF communications chain from headquarters, transmitter sites, to the submarine platforms. We continue to support, refine and refresh those systems via long term contracts with the UK MoD and other MoD Prime Contractors.

All of our current systems have been developed to be compliant with NATO STANAG 5030 Edition 4 and our newly developed products capable of implementing the newly ratified NATO STANAG AComP 4724.

To aid system development, Drumgrange has developed a sophisticated numerical (Matlab/Simulink) modelling environment to support link budget estimation, Sea Water penetration predictions and overall system performance analysis.

We work closely with CESG, the UK Government's National Technical Authority for Information Assurance, during the development and security accreditation of High Grade devices required within these programmes.

The VLF Communication product range can be broken down into the following categories:


MSK Demodulators (DDS457)
Designed to meet all the requirements of NATO STANAG 5030 and future AComP 4724 implementation, the DDS457 can be configured in either dual or single demodulator mode. The DDS457 enables the continuous off-air data recovery of MSK (M4, M2 & M1) and FSK transmissions from VLF/LF radio receivers. The DDS457 has been designed for platform installation but is equally applicable for shore based off air monitoring applications.

VLF/LF Multimode Transmitter Drives (DDR310)
DDR310 enables up to 4 x 50 (or 75) baud keystream data inputs to be formatted and modulated onto a high-stability VLF/LF carrier. The variable level output modulated carrier is then passed to the associated transmitter power amplifiers for transmission. The DDR310 provides the core elements of a system which can be expanded, through the use of plug in modules, to include Keystream processing, demodulation for off-air monitoring, AComP 4724 implementation, automatic antenna fine tuning and Ethernet connectivity including remote control and data input.

All products include comprehensive built-in test detection and reporting mechanisms.