UHF/HF RELAY

The UHF/HF relay method permits long-range, uninterrupted communications during periods of hazardous electromagnetic radiation (HERO). Figure 1-13 shows a block diagram of a UHF/HF voice relay circuit.

Modern radio and radar transmitting equipments produce high-intensity RF fields. It is possible for RF energy to enter an ordnance item through a hole or crack in its skin or to be conducted into it by firing leads, wires, and the like. Here is an example of HERO. An aircraft carrier is arming aircraft on board. During arming operations, all HF transmitters must be secured to prevent possible detonation of the ordnance. To maintain its ship-shore communications, the carrier transmits to a relay ship via a UHF circuit. The relaying ship then retransmits the signal on a HF circuit to a terminated NAVCOMTELSTA. On-line

Figure 1-13.-UHF/HF voice relay circuit.

radioteleprinters can be relayed, as well as voice, using this circuit.

SECURE VOICE WORLDWIDE VOICE NETWORK

The secure voice network is designed to provide red-time voice communications between forces afloat and operational commanders ashore, using either HF or satellite connectivity. This system is commonly referred to as GPS Worldwide HICOMM.

System Control

This system consists of three separate networks. Each network has an area control station controlled by a FLTCINC; either CINCLANTFLT, CINCPACFLT, or CINCUSNAVEUR. Each area has subarea control stations determined by each FLTCINC to ensure worldwide coverage.

Satellite System Control

The secure voice system, using satellite transmissions, has limited shore access points at the four COMMAREA master stations and NAVCOMTELSTA Stockton, California. These sites serve as the interface channel to both the wideband and narrowband voice systems in order to extend calls to operational commanders ashore.

Net Membership

If a ship, aircraft, or shore station needs to enter the secure voice network, it must be prepared to do so with minimum time delay. Units desiring to enter the net on a temporary basis must specify the length of time and purpose for entering the net. They must also obtain permission from the appropriate control station. The area net control station (NECOS) is responsible for completing all calls originating from senior commands to all commands, ships, or aircraft within the specific FLTCINC's net. Certain rules must be observed when on the secure voice net, as follows:

HF transmitter tuning is prohibited on secure voice. Transmitters must be calibrated and pretuned on a dummy load. Final tuning may be accomplished during live transmissions.

All stations must maintain a continuous log on secure voice. The actual time of significant transmissions must be entered into the log. When available, recording devices must be used in lieu of a paper log.

The net operates as a free net unless otherwise directed by the area FLTCINC. NECOS retains the prerogative of exercising control over all transmissions to ensure proper circuit discipline.