Marlborough East

The Marlborough East repeater site houses the 29.68 and 53.81 transmitters. This site is also the former site of the 146.61 repeater, which is now located in Mendon, MA.


29.68 Transmitter
The 29.68 repeater operates split site, with its receiver at the MMRA Weston Site, and the transmitter here at Marlborough East. For more information about the receiver, see our page on Weston.

The 29.68 transmitter is a GE MASTR II base station. The base station includes a UHF receiver, and 100W power amplifier. The receiver picks up the incoming UHF link frequency (from the Weston site) and hands it to the 10m transmitter. The repeater shares a SCOM 7K repeater controller with the 6m transmitter

The repeater was installed over several days in July, 2009.


53.81 Transmitter


This repeater was installed and has been operating nearly continuously since October, 1996.

The 53.81 repeater operates split site, with its receiver at the MMRA Marlborough West Site, and the transmitter here at Marlborough East. For more information about the receiver, see our page on Marlborough West.

The upper photo is the 53.81 GE MASTR II base station, including a UHF receiver, a Uniden UHF link radio, a Mastr II 6m exciter, and the older 4CX250-based 300W power amplifier which was retired from service in January 2010. It was replaced with the Larcan amplifier shown at the top of the lower photo. Below the Larcan is a meter panel, and at the bottom the 50V, 40A power supply for the amplifier.

The UHF receiver picks up the incoming link frequency (from the Marlborough West site) and sends it to the 6m exciter by way of the controller. The 7K controller adds the courtesy beep, voice and CW id, and control functions. (This controller also controls the colocated 10m transmitter) . The 6m repeater is capable of running independently sing a backup Hamtronics repeater controller as well.

The Larcan transmitter was originally part of the WTAE (TV ch. 4) transmitter in Pittsburgh. MMRA acquired several transmitter modules like this one from WTAE and other stations, and sold them as a fundraiser for the club. MMRA also kept three for club purposes, this being one of them. Although the module is capable of operating 600W continuous duty on FM, this one is running at about 350W.

The original construction of the repeater project took place during the summer months of 1996. Bryan modified the tube power amplifier by removing a turn on the plate coil and changing the topology of the grid circuit. Additionally, the PA low pass filter section's doorknob-type capacitors needed to be changed. The Larcan work began in October 2009 and was installed on January 30, 2010.



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