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 and 927.700 repeaters, and the MMRA APRS node on 144.390.
In the above photo, you can see the main HUB repeater 449.925, alongside 147.270.
|The 53.81 repeater operates split site, with its transmitter at the MMRA Marlborough East
site, and the receiver here at Marlborough West. The receiver is actually two receivers. These
feed a receiver voting system. The receiver with the strongest incoming signal is feed to the link
transmitter for transmission to the transmit site about 3 miles away. Yes, we have two receivers at the
same site: Our antennas are side mounted on a large steel water tank, which creates a complete 180 degree
shadow. One antenna is on the North side of the tank, the other on the South, so the two patterns combine
to create 360 degree coverage.
For more information about the transmitter, see our page on Marlborough East.
|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 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!|
|The 224.880 repeater 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, and the repeater is controlled by an SCOM 7K controller (shared with the 147.27 machine).|
|This is the center of MMRA's network. All repeaters in our network link through here. The HUB is a Motorola Micor Compa-station with an SCOM 7330 controller. At the top in the photo is the backside of the duplexer. Below this you can see the Motorola M120 Echo/IRLP link radio. Next is the DSL modem, followed by the controller. Below the controller, you see the guts of the Micor (TX, card cage, receiver, and power supply).|
|The latest addition to the MMRA Marborough West site is this MSF5000 927MHz repeater. Yet another SCOM 7K controller takes care of this puppy. The finals on this repeater put out close to 200W. Coupled to a PD809Y antenna over 100 feet up, this repeater has a wide range. This repeater is full-time linked to the NEAR-900 network, a collection of 900 MHz repeaters throughout Massachusetts that are linked through an IRLP reflector.|
|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.|