NOVA SCOTIA HOSPITAL GRID

This page describes or depicts a system that no longer exists
and therefore there are no issues of confidentiality.

This system was a component of the NS Integrated Mobile Radio System throughout the 1980’s and 1990’s. It was replaced by the 800 MHz NS Trunked Mobile Radio System in the year 2000.

Ambulance repeaters were installed at each of the 24 NSIMRS primary sites, as shown on the chart. At the very end of the NSIMRS era this network was expanded to include sites not in the NSIMRS system. Information is sketchy but apparently some frequencies and possibly sites as well were inherited from the VHF Mobile Radiotelephone service that had been abandoned in favour of cellular telephones

The indicated dial-up code was used by a unit in one area in order to connect with a distant repeater or with hospitals. The user brought up the local repeater and dialled the distant repeater or the hospital by inputting the dial-up code. Note that the dial-up code for a distant repeater was the site number + 400. For example, an ambulance operating near Truro would be on the Nuttby Mountain site, and to dial the Halifax area would dial 410. Dial-ups for hospitals were in the range beyond 424. It was possible for ambulance users to be connected to the other networks in the system by dialling the operator at Shubie Radio (dial-up code = 0) who would make a manual patch.

Unlike the other grids in the NSIMRS, this system had very few frequencies. All but two repeaters used the 158.91 frequency but with a different CTCSS tone. Sydney and Halifax used the other frequency 158.94 because they were much busier. In addition to the repeater frequency pairs there was also a simplex frequency 158.76 MHz which was also in common use for communicating with hospitals when in close proximity. Tones and channel numbers are not known for most repeaters. Several of the repeaters seemed to allow a wide range of tones for access, for example at Garland, which is listed for CTCSS 136.5, both the next lower and next higher tones in the CTCSS sequence also accessed this repeater.

Note that the map shown here of the system has written in Channel numbers however these are channel numbers for the New Brunswick ambulance system, as their ambulances had the channels from the border to Halifax. These channel numbers are NOT the ones used by NS ambulances.

Site #	Rptr Site	Area Served	Dial-up Code	Channel #	Frequency (out)	Input frequency	CTCSS Tone
1	Middle Ohio	Shelburne	401		158.91	159.69	1 (71.9)
2	East Kemptville	Yarmouth	402		158.91	159.69	2 (?)
3	North Range Corner	Digby County	403		158.91	159.69	146.2? or 3 (94.8)?
4	DND	Annapolis	404		158.91	159.69	4 (?)
5	Springfield	Springfield	405		158.91	159.69	5 (?)
6	Garland	Kings County	406		158.91	159.69	8 (136.5)
7	Liverpool	Queens County	407	26	158.91	159.69	6 (118.8)
8	Sherwood	Lunenburg County	408		158.91	159.69	7 (127.3)
9	Willow Hill	West Hants	409		158.91	159.69	2 (?)
10	Hammonds Plains	Halifax	410		158.94	159.87	7 (127.3)
11	Jerusalem Hill	Musquodoboit Hbr	411		158.91	159.69	4 (?)
12	Marinette	Sheet Harbour	412		158.91	159.69	5 (?)
13	Kirkhill	Parrsboro	413		158.91	159.69	1 (71.9)
14	Sugarloaf	Cumberland County	414	37	158.91	159.69	6 (118.8)
15	Nuttby Mtn	Colchester County	415		158.91	159.69	3 (94.8)
16	McLellan's Mtn	New Glasgow	416		158.91	159.69	7 (127.3)
17	Cochrane Hill	Sherbrooke	417		158.91	159.69	8 (136.5)
18	Fairmont	Antigonish	418		158.91	159.69	2 (?)
19	Lundy	Guysborough	419		158.91	159.69	1 (71.9)
20	Oban	St. Peter's	420		158.91	159.69	6 (118.8)
21	Rear Boisdale	Sydney	421		158.94	159.87	5 (?)
22	Kiltarlity Mtn	Inverness County	422		158.91	159.69	4 (?)
23	Cape Smokey	Ingonish	423		158.91	159.69	3 (94.8)
24	Money Point	Cape North	424		158.91	159.69	8 (136.5)

Tone 1 (71.9) is listed in some sources as tone 69.3

Note that the channel numbers vary with the output frequencies and the CTCSS tone.

On the map below the channel numbers written in were those used in New Brunswick ambulances travelling to and from Halifax. Apparently they were not equipped to access the other repeaters as their path from the border to Halifax and return would only require these four repeaters. Even the need for the Kirkhill repeater (Channel 20) appears questionable as it is not actually on the route. Most likely the sequence of Sugarloaf, Nuttby and Hammonds Plains would be adequate.