900 MHz Repeater Update

On Saturday, September 19, 2009, SEMARA’s new 927.8375 repeater was placed on the air.  The repeater is a Motorola MSF-5000 with its antenna on top of the 180 foot tower along with the 147.000 repeater.  The plan was to add IRLP to the repeater in order to link it to a growing eastern Massachusetts repeater network known as New England Amateur Radio 900 (NEAR-900).  As of Saturday, June 12th, we are now one step away from linking the repeater to the network.

At 2:00pm, Rick, W1RJC met up with Jeff, N1ZZN and Ho, KC1HO at SEMARA.  The crew started at the clubhouse with Jeff programming a few Motorola 900 MHz mobile radios (including one that is to be mounted on the wall).  Rick reconfigured the underground CAT-5 cable that runs between the clubhouse and repeater site to carry two ethernet connections.  This will be necessary so that the 2 meter and 900 MHz repeater’s IRLP can be on two different Comcast IP addresses.

About an hour later, the crew headed out back to the repeater site.  In order to link the repeater to NEAR-900, an external repeater controller is required.  A repeater controller is the brain of a repeater which tells it when to transmit and routes the audio, courtesy tones and IDs accordingly.  The repeater’s receive and transmit audio along with logic control for the receiver carrier operated squelch (COS), receiver PL decode and transmitter push to talk (PTT) needs to be wired to the controller.

After a few hours work and a trip to Rick’s house to pick up some parts, a DB-9 port was added to the repeater.  Our brand new repeater controller, the Arcom RC-210, was then connected via a shielded patch cable to this port.  After adjusting the squelch and audio levels in the controller, the installation was a success!  The crew then headed to Texas Roadhouse in Dartmouth for some well deserved food.

Following dinner, Jeff and Rick headed back to SEMARA.  The Kenwood TS-570 HF/6m radio was fired up to check out this weekend’s VHF QSO Party.  There was a fairly decent 6 meter E-skip opening which allowed Jeff to log at least five contacts in the SEMARA logbook.  Most of the stations were from 4 land including Florida and Kentucky.

The final piece of work in linking the 900 MHz repeater into NEAR-900 will occur in the upcoming week by Rick.  A patch cable will need to be modified to allow the new IRLP computer to be connected to the repeater controller.  The computer must also be tested to make sure that it can acquire a separate IP address from the cable modem (a router will be added later).  Audio levels for the node need to be adjusted via the repeater controller as well.  A second update will be posted here when the link is complete and up and running.  Stay tuned! 🙂