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Flashing new "DC free" control firmware

Submitter: Menno Norden
Description: Over the last year, the HBA failure rate has been growing alarmingly, due to drainage problems on the Dutch LOFAR fields. Water that got trapped in the tile enclosures was causing humidity levels between 80 and 100%. The electronic boards inside the tiles are coated, but not well enough to prevent damage on the control-summator and HBA-frontend board.

A few solutions to the humidity problem are under investigation at the moment. One is a better drainage of the HBA field by digging a ditch around the array. A second is to completely fill the control-summator with epoxy, so that water vapor cannot affect the electronics anymore. The third option is to remove the DC voltage from the control lines when no communication signal is present or when the LBA array is in use. With such modifications we hope to stop or at least slow down the corrosion process.

Unfortunately, the firmware of the receiver cannot be modified ("flashed") remotely. Therefore, all Y-receivers have to be temporary removed from the subracks to connect the PicKit-3 programmer unit with the programming header. A total of 33 stations, with 48 boards each, where updated in this way.

A special construction was made by Eim Mulder to support the programmer unit. I also gratefully acknowledge my wife, who lent me a clothes-pin to snap the unit onto the coaxial cables ;). This leaves one hand free to press the program button. Efficiency is in the little things.
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