The frequencies in the table above are in limited use by Hope Fire and Rescue but are still utilized for communications with Clearfield County for mutual aid incidents.

800 MHZ Trunked Radio System
Hope Fire and Rescue has moved its primary operations to the 800 MHZ
trunked radio system for Centre County. The initial dispatch (paging) is simulcast
on 800 MHZ and a county paging frequency of 453.975 MHZ. All Minitor II pagers
are tuned to the county paging frequency. Once an officer establishes command,
an operations channel is assigned and the simulcast is ended. All radio traffic then occurs on the trunked radio system.

So What Does Trunking Mean?
There are two types of radio systems, conventional and trunked. In a conventional system the radio message between the station and units in the field occur on one frequency. At any given time, some of the frequencies or channels may be so busy that messages are delayed or "stepped on", while other channels are lightly used or not used at all. When several departments share a single frequency, they may cause interference with each other. This is the case with the low band fire frequency 46.140 MHZ. Trunking is a method that utilizes all frequencies in the radio system to its maximum potential. In a trunked system, all stations and units share all the frequencies. When a message between a station and a unit is commenced, the trunked system automatically selects an unused frequency and switches all radios in the system to that frequency. No one frequency is assigned to any department and the frequency could change every time a transmission is made. In a trunked system, one frequency serves as the control or "hand shake" channel. The control channel can be recognized by the loud buzzing noise and is switched to a different frequency each day. This buzzing is the data stream that all radios tune to, this is done automatically. The entire system is managed by a computer known as a Site Controller. When a microphone on a radio is pressed, a signal goes to the Site Controller which selects an unused frequency. The Site Controller then sends out data on the control channel and switches all radios to the appropriate frequency. In the Centre County Trunked Radio System, there are actually two systems in operation. A one tower trunked system serves the State College region of the county. Agencies on this system include State College Police and Penn State University and reception is limited to this area. The second trunked system is the super system and is county wide. Reception can be received throughout Centre County by the use of multiple towers and services include the Fire Departments and Township Police Departments.

© Copyright 1997 - 2008 CentreCountyFire.com
All Rights Reserved