Marlborough West



MRW Tower The MMRA Marlborough West site is the hub of the MMRA repeater network. Every repeater in the system has a link directly to our repeater on 449.925 MHz. This site is also home to:
  • the 53.81 receiver,
  • the 147.27,
  • 224.880,
  • 448.225 and
  • 927.700 repeaters
  • the MMRA APRS node on 144.390 and
  • two IRLP nodes.
  • Here is your first look inside the shelter. 449.925 and 147.27 are on the left.
    On the right side (front to back) we have the IRLP computers and DStar repeater, a work bench, then the remaining equipment: APRS, 52.81 rx, 224.88, 447.875, and 927.7.
    53.81 Receiver
    The 53.81 repeater operates split site, with its transmitter at the MMRA Marlborough East site, and the receiver here at Marlborough West. Both the 6m receiver and UHF link transmitter are in Mastr II cabinet. For more information about the 6m transmitter, see our page on Marlborough East.
    147.27
    The 147.270 repeater has been operated by MMRA since 2003. It was acquired from another amateur radio group who had operated it for at least 20 years prior as a tenant in MMRA's shelter. When acquired, this repeater was a Motorola base station repeater controlled by an ACC RC-850 controller. This equipment was retired, and replaced by a GE Mastr-II base station and SCOM 7K controller. The 7K controller was replace in 2017 with an SCOM 7330 controller. This unit also operates the 224.880 repeater and the link transceiver. Interestingly enough, the 147.270 repeater is linked to the hub via RF, even though the hub repeater is in the same shelter about two feet away. Although a hard-wired link is possible, it requires an additional port on the hub's controller, and increases the overall complexity of the system. The link transceiver is dual channel and can be set remotely to link to either HUB1 or HUB2. By the way, the ACC RC-850 controller was sold on eBay and is now operating a repeater in Southeast Australia!

    147.27 is equipped with battery backup power and can operate thirty to sixty minutes during a power outage.
    224.88
    The 224.880 repeater (top of rack) looks like a VHF Engineering repeater, but looks can be deceiving. Although the transmitter is the original equipment, all other components of the system have been replaced. The receiver is a Maggiore R4V.

    The repeater can link into the MMRA network via UHF. Below the repeater, you see the link radio which is shared with 147.27 for this purpose. Two more positions down, you see the SCOM 7330 controller which controls 147.27, 224.88, and the link radio.
    448.225
    "W1MRA B" is the newest addition to the Marlborough site. On loan from N1PA, this is the second D-STAR repeater sponsored by MMRA. Below the ICOM stack, you see the duplexer, and below that the Dell workstation in service as the gateway.
    449.925
    This is the center of MMRA's network. All repeaters in our network link through here. At the top in the photo is the backside of the duplexer. Below this you can see the Motorola M120 link radio, which allows '925 to link to 446.325 in Brookline or 448.625 on Mount Wachusett in Princeton. There is also a small receiver cavity on the right. The SCOM7330 is next. Below this controller, you see the guts of the Motorola Compa-station: TX, card cage, receiver, and power supply.

    449.925 is equipped with battery backup power and can operate thirty to sixty minutes during a power outage.
    927.700
    MMRA's 927.7 is a Motorola Quantar repeater. An SCOM 7K is the controller for this system. The finals on this repeater put out close to 100W. Coupled to a PD809Y antenna 180 feet up, this repeater has a wide range. This repeater is IRLP node 4978 and full-time linked to the NEAR-900 network, a collection of 900 MHz repeaters throughout Massachusetts that are linked through an IRLP reflector. The duplexers you see at the bottom are for 224.88.
    144.39 APRS
    MMRA hosts an APRS repeater at this location. It is a Kantronics KPC-3 Plus TNC and a 100W GE Delta SX mobile transceiver running at 50W.
    IRLP/Echolink
    Since the early to mid 2000's, two IRLP nodes have operated from this site. The current nodes are based on Raspberry Pi Model B processor boards and are contained in the black 1U cabinet above the APC power controller. They were placed in service in 2016 and replaced the 1990's era "White Box" PCs on which the original nodes were built. Photo of original nodes.


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