7 May 2008
To: SBARC Telecommunications users From: Bill Talanian, Telecommunications Services Subject: Down systems
By now most everyone is aware of the many disparate problems that have caused our systems to go down in the past few weeks. These problems are not due to any one cause but different events all culminating at the same time. The service and maintenance is remanded to only a handful in SBARC who have the knowledge and ability with the proper test equipment and diagnostics to bring systems back on line when they fail. The complexity of our equipment both in hardware and software is not something we entrust to just anyone. It takes a lot of hard work and man-hours to fully understand our equipment and its interfaces. In most cases this requires the ability to design and engineer what is required for any particular function or interface. There is a theoretical limit in how much we can expect from individuals when they must also pay attention to their job and needs at home. We are fortunate to have the talents and time given to us but we are also careful to recognize when people are stretched to the limit to maintain Club equipment. We will focus on these issues one at a time and beat them down. So please bear with us during this period.
146.790 Repeater The first stages of this problem was noted when the system was regenerating "trash" once the receiver breaks tone squelch with the transmitter on. Several local attempts were made to isolate the problem without the use of test equipment but these basic techniques were unsuccessful. It was noted that the UCSB voting receiver was not causing a problem. Rather than shut the system down the UCSB link and La Vigia transmitter have been kept in operation until we can get the calibrated service monitor and spectrum analyzer on site for troubleshooting. The proper test equipment is generally in the hands of very few people, especially those who know how to use it. In some cases the test equipment is part of shop inventory by those in the government and private sector. In general most organizations frown upon non-official outside private use of expensive test equipment by any employee, especially with transporting it to a remote site. We are left to only one or two who have such equipment and willing to bring it to the site.
Digital Communications At the La Vigia site SBARC has a rather very extensive digital systems interface to several individual systems. This includes two computers with interfaces to IRLP, APRS, Weather Data, WebCam, and variations of packet forwarding including WinLink. These systems are also interfaced with one DSL line which is also shared with the site phone going to two repeaters. After spending many man hours with our ISP troubleshooting and replacing specific units such as the Router and Modem we concluded that the particular problems may be associated with the telco line and its ability to properly "sync" up with our local modem. A request has been submitted to Verizon for an on-site service call to check out the telco line between La Vigia and the ISP.
223.92 Santa Cruz Island This system has been temporarily shut down due to regeneration of the transmitted output. Our first guess is that this problem is associated with the weather station on site. It will be the end of this month before we can get out there to do what is necessary to bring this system back on line.
Portapeater In general this system needs some attention to bring it back on line. Again, a situation that we cannot trust to occur without the basic service monitor equipment.
********************