When there’s a need to extend the coverage of handheld two-way radios, the first option is usually a repeater. However, a repeater isn’t the full answer. A repeater will typically put out much more power and have a better antenna system than the portable radios with which it is communicating. This presents an unbalanced system where the transmit power of the repeater reaches much further than the transmit power of the handhelds.
Couldn’t this be resolved by turning the power of the repeater down to match the handheld? The reality is that often times mobile radios installed in vehicles and handheld radios are in use on the system. Mobile radios typically have greater transmit power than handhelds. Reducing the repeater power output to match the lowest powered device – the handheld – significantly constrains the system coverage, making the usable radius of the system much less than what it could be.
To fix this, users can implement a digital voting system, such as Icom’s IDAS™ LINQVOTE, that can easily plug in “voting” receivers. This allows the system builder the choice of placing receivers locally where ever they know portables to be working from. This system then “votes” the receiver that is receiving the portable operator the best.
The net effect is that the system now becomes much more balanced and the usable radius of the system is significantly enhanced. You can think of this kind of system as being a “repeater” with a distributed receive system.