Repeater Systems
A Repeater is a device that can more than double the range of Back-to-Back Systems. It will improve coverage in difficult buildings or expand coverage over many miles for wide area systems.
The Repeater is a standalone (sometimes portable) device located somewhere central to the area that needs radio coverage. It consists of an aerial mounted in a high location and the repeater itself which is powered from the 240/110v, 12v or even solar power.
The repeater picks up the weak signals from distant radios and rebroadcasts them at high power. This process is instant and automatic and users will be unaware they are talking via the repeater.
- A repeater requires no operator so is often a preferred choice to a Base Station.
- Repeaters can be linked between widely spaced sites. See IP Site Linking
- Repeaters can be used with multiple channels. See Trunked Radio Systems.
Repeater Installation
Aerial
The aerial is the main constraint. It should be at the suitable height to give the required range. It should be above local obstructions; walls, parapets, especially metal cladding and other metal work. It must be clamped to a secure part of the building to secure it during the worst of expected storms.
Distance from the aerial
The repeater should ideally be no more than 10m of cable run from the Aerial. Longer cable runs give receive signal loss which results in loss in range.
Repeater Housing
The repeater should be located in a dry and dust-free location well ventilated to allow cooling in summer and prevent condensation during sudden temperature changes.
Repeater Power Supply
Repeaters need 24hour mains power of 12VDC or 90-240VAC of about 200VA. This should be a fused and earthed supply. A 12v lead acid battery can be connected to many repeaters to allow running when the mains fails. If so it is advisable to set up the repeater to send an alert to all radios once mains fails.
Maintenance
Repeaters are largely maintenance-free (back up batteries excepted) and usually run for years without intervention however they should be readily accessible to enable checking of connectors and aerial connectors.
A repeater being installed and programmmed.
The Unique PD985 Pocket Repeater
