April 2010


HF Tomorrow and

- ALE IV


There was a time when a number of people thought that the days of HF radio were numbered. The advent of first the high orbiting geostationary satellites systems like Inmarsat providing marine and military telephone services and traffic monitoring services on ships at sea, the success of GSM mobile terrestrial cellular telephone networks, and the promises of the low earth orbiting Iridium satellite telephone system, all seemed to confirm it. Communications, once the preserve of the highly skilled professional, had suddenly became user friendly and available to the masses.

While the improvements provided by 3G ALE are significant, the retention of 2G is not only for the purposes of backwards compatibility and interoperability. There are still some features of 2G that work better in some circumstances. Therefore today’s systems support both 2G and 3G ALE to provide best solutions and 3G ALE incorporates embedded control protocols for many popular transceiver types.

Where signal to noise ratios (SNRs) are low, the slower synchronous scan, short link establishment transmission and high frame error rates of 3G makes linking possible in poor conditions. However, where SNRs are average to good, the fast asynchronous scan, longer link establishment transmission and low frame error rates provides comparable or better performance. Moreover, the time delay in waiting for the desired frequency dwell to happen in the 3G synchronous system can have a significant impact.


2nd Generation HF Key NATO Standards
MIL STD 188 141A ALE
STANAG 5066 ARQ
STANAG 4285/4539/MIL STD 188 110B Modems
STANAG 5066 Subnetwork
STANAG 5066 HF Clients

3rd Generation HF Key NATO Standards
STANAG 4538 ALE
HDL & LDL (STANAG 4538) ARQ
BW1-5 (STANAG 4538) Waveforms
STANAG 5066 Subnetwork
STANAG 5066 HF Clients

A radical feature of today’s 3G HF technology is that all components are interdependent to a significant degree and cannot easily be separated out to mix and match with other components and form different product, as with the multi-vendor 2G system. For example, modems, ARQ and ALE are tightly coupled.

Where battle force email applications are concerned it is important to note that 3G HF with xDL does not use non ALE HF radio and is not compatible with existing NATO/US cryptographic devices placed between the ARQ output and the physical transmission medium. Also, it only partially supports asynchronous operation with minimal pre co-ordination. All these features are supported by STANAG 5066 compliant HF. xDL ARQ protocols are time rather than event driven with automatic adaptive coding rate adjustment to match channel conditions, which require dual demodulation at the waveform level and strict timing constraints.

The need for interoperability between new and previous generation technology is stressed. Combined Endeavour, an exercise organised through NATO’s Partnership for Peace program, sponsored by the US European Command, plays a significant role in ensuring systems are compatible for humanitarian and peacekeeping operations and disaster relief. Now in its 15th year (2009), this exercise is essentially a communications and information systems interoperability test between and among Partnership for Peace and NATO nations. The focus is on deliberate planning process, communications information systems interoperability, and development of a road map for future interoperability improvement among participants.




Compact Guyed MF System

type 150MF

- for NDB, DGPS and AM communications

The Moonraker 15 metre 150MF system (50ft) guyed whip offers compact performance in the 250 kHz to 3 MHz range for low power AM broadcast stations, non directional beacons and differential GPS base stations.

Systems are tailored to suit individual frequency and ground conditions. A suitable ATU is required (not supplied). Antenna wind survival is to 216 km/h (134 mph). Supplied complete with guys and swing up base mount system. Earth mats are available to suit.

- type 150MF

  • swing up base available for ease of erection and demounting
  • horn gap lightning protection available
  • earth mats designed to suit ground conditions


100 - 80 Series

High Survival, High Performance HF

- for GMDSS marine and land base stations

Approved for GMDSS use, 100 and 80 Series HF whips offer excellent performance which will last over time. Antennas are designed for 200 km/h (125 mph). wind survival with 1.2kW PEP power capability.

The 10m and 8m whips (32.8ft/26ft) are constructed from heavy duty marine quality aluminium which is given an epoxy coating to ensure enduring protection against the marine environment, being highly resistant to chemical attack, abrasion and the effects of ozone and ultra-violet radiation. Joints are sealed using a special sealing kit and covered with flexible boots.

Both base mounting (choice of base or side feed), and side mounting are available together with an optional tilting mount

- 100 Series & 80 Series

  • base mount with side feed
  • base mount with base feed
  • side mounting
  • manual adjust tilting mount available


Avoid Noise Interference

- in receive systems

type MRA RX Transformer

Perhaps the most difficult location to site an antenna for receiving or GMDSS watchkeeping, is on vessels where there is a great competition for space.

With the MRA RX Transformer , it is possible to locate the antenna up to 70m (230ft) from the receiver, and even further away with use of low loss cable, making it much easier to avoid possible interference from ships wiring and electronic equipment. Overvoltage (lightning) protection is built in.

Suitable for whip or wire antennas in both marine and land applications.

- type MRA RX Transformer

  • 0.3-30 MHz
  • single coaxial output