Dukes County - Martha's Vineyard
New Communications System - June 2021

     Fire, EMS, and Police communications on Martha's Vineyard changed on June 4, 2021 when their new system was activated.
     While the full workings of the system are still being learned, essentially the Dukes County Sheriff's Department, who dispatches all agencies on the island, has built a new infrastructure with several towers across the island and all new digital radios.
      The old system utilized conventional VHF frequencies including:
154.325 (252) which was used as the tone out, paging, initial dispatch channel for all fire and EMS units on the island.
153.770 (838) was then utilized by fire apparatus responding and operating
158.790 (229) was utilized by ambulances responding and operating.
158.850 (860) was the primary Law Enforcement dispatch channel.
      There were other frequencies, but essentially those were the main used.

      The NEW SYSTEM added NEW frequencies, with digital capability. All radios transmit the unit ID with a keyed mic. All radios apparently have the same programming of channels enabling interoperability functions across agencies. At this point, dispatch is known as "CONTROL" on all channels, which is a significant change from the 252, 838, 229, 860 call signs of past.
     It appears there is a bank of PD channels (A bank?) and a bank of FD EMS channels (B bank?). Additional channels (C bank?) include other agencies.
154.1225  nac115 - Appears to be the Primary (B1) Fire-EMS Tone Out and Dispatch channel. Equal to the 154.325 (252) function.
155.4375  nac 252 - Appears to be the Primary TAC (B2) channel. Calls also put out on this channel and most initial talk with and by units responding and operating at incidents. The Sunday morning 10:00 radio checks on this channel.
155.9250 (unk code) - Appears to be the "Down Island OPS" channel. This has been assigned by Control upon dispatch of 2 or more agencies to an incident on the East end of the island (ED, OB at least).
_______ (unk code) - Appears to the be "Up Island OPS" channel. A channel that would be assigned for incidents on the West end of the island.
There are also at least 4 "Fireground" channels. More to follow as learned.

     The Law Enforcement System is similar.
156.2175  nac D10 - Appears to be the Primary Police Dispatch channel for some, if not all, Police Departments.
     There are a number of other Law Enforcement channels that are utilized by communities, OPS channels for multi agencies, and more.

      As further information is available it will be updated.

      June 10, 2021