Rebroadcast 'echo'

[fbaker]

Wondering what causes an 'echo' effect when a rebroadcast system is used for paging? Local dispatch for fire/EMS recently has install of a rebroadcast system (taped first and then rebroadcast to radios/pagers) which is kind of irritating to say the least. What happens is the dispatch hits the 'tones' then it says the message which can be heard at a VERY low almost indistiguishable audible level, then immediatly after releasing the button, the tones and message rebroadcast loud enough to be heard and understood. Now this usually only happens on one of the two frequencies that are used and this one is the WIDEBAND page frequency still allowed for public safety When the broadcast system, which has two seperate tones for the two different local responders is used, the first tone out has NO echo issue, however, when it is used for the farther distant service, this 'echo' effect takes place. The dispatch stil use a third, older, multi-tone system for another service, however it is dispatched on a NARROWBANDED channel allowed for dispatch and 2-way commo. As far as I know this NEW system is still using the OLD VHF simplex system. Also have heard from many responders in this 'echo' service area that they sometimes don't get the page and message or it is very garbled. They respond to the station anyway and get the details from others who have been lucky enough to gather the whole page. There is a
'rebroadcast' radio in the local city hall that supposedly picks up that first signal output and resends it. Seems odd that one half of the system would work as it is supposed to and the other not. Any answers/suggestions on how to fix/where to look for correction of this fault. Thanks