MARITIMES SCANNING SITE

NOVA SCOTIA FIRE GRID
Last updated April 2, 2010

The fire grid is a system of vhf repeaters in Nova Scotia that was intended to be a local and regional wide-area resource for volunteer fire departments.   Not only would it allow individual departments to have reliable coverage over their complete service area, it would also allow intercommunication with other departments in the region at a level higher than that allowed by the simplex 153.83 frequency.    In addition the repeater could be used as a paging transmitter, and allow for multi-department page-outs.   Finally, because these sites were linked together, any user with a suitably equipped radio could dial-up a central dispatch site for patching to other services or to allow communications throughout the province.    This system was a component of the
NS Integrated Mobile Radio System, which has largely been replaced by the 800 MHz NS Trunked Mobile Radio System.  This component has been left in place as it is used on a daily basis in parts of the province for volunteer fire department dispatch and operations.  Some sites are virtually unused today.  This is true within the Halifax Regional Municipality (Hammonds Plains, Jerusalem Hill and Marinette sites, due to all local fire services having gone to 800 MHz.  It is also true for the Willow Hill repeater, as the local area has its own VHF system and no longer uses the grid.

Despite the lack of use of some sites the system in its entirety seems to be enduring and may or may not be still maintained by the province.   Possibly local authorities are keeping the repeaters going.  Due to the advent of the TMR much of the usefulness of the fire grid has been lost, except for the local communications function.    The links between sites and the central patching connection at Shubie Radio have been eliminated almost entirely; however there may still be some links still functioning, merely because they have not been decommissioned.

Please note that several repeaters remaining from the former Department of Transportation system are now considered to be parts of the fire grid.   See list of such repeaters at the bottom of this page.

The following is the information pertaining to the linked system as it was but is now thought to have been virtually discontinued and no longer monitored by the central site at Shubie Radio: A dial-up code was used by a unit in one area in order to connect with a distant repeater.   The user brought up the local repeater and dialed up the distant one by inputting the dial-up code.  Note that the dial-up code was the NSIMRS site number + network number (100) + 19.  It is not known why the code could not be 101, 102, etc. (similar to the pattern in other NSIMRS networks).  It was possible for fire grid users to be connected to the EMO/GSS network and perhaps also to the NSTMRS by dialing the operator at Shubie Radio (dial-up code = 0)

 A map of the grid appears here

While the provincial government intends that these repeaters remain in stand-alone operation there is some variation in the present status. The status column is incomplete.  It is intended to show if the particular repeater remains in operation in 2009-2010.   Abbreviations are OOS Out of Service, OSA Operational as a standalone repeater only,  OSA? is the same except that it might also be linkable,   OSL means that it not only is operational for stand alone use, it can also link to at least one other site by dial up.  This may be either from or to another site or both directions.  A blank means that nothing is known.   Most of this information re status comes from the fact that in many areas these repeaters remain in common use for pages and/or operations.    It is thought that all or practically all sites are still operational even if not used.   Those shown as still linkable have been reported as such by fire department users who have actually utilized the link system in 2009, in which case the mere fact it worked at their local repeater is evidence, but also if it brought up the chosen distant repeater that is evidence for that distant repeater.   Bringing up a distant repeater can be known for sure by hearing that repeater come up over the air if it is not too far away, or less assuredly by hearing no negative tones when it is dialled up.  "Unused" refers to the fact that although the repeater is present and functioning, there are no departments in the area to use it; however that does not mean that there might not be backup radios  available to use if other systems go down.

PROVINCIAL SIMPLEX (MUTUAL AID) 153.83

Note that the channel numbers vary with the output and input frequencies, not with the CTCSS tone. 
In some cases the same output frequency is used in two different channels, but with a different input frequency.

FORMER DEPT OF TRANSPORTATION REPEATERS NOW CONSIDERED TO BE PART OF THE FIRE GRID REPEATER SYSTEM.   THESE MAY OR MAY NOT ACTUALLY BE IN USE.   The Barr Settlement frequency is integrated into the East Hants fire radio plan.   The Salem site seems to be in use by at least the Truemanville VFD.