Westerbork station report June 2001

Hardware

• Just before the November 2000 session we had to replace worn bearings in a reel motor. This was giving a wobble in the tape hence poor recordings.
• The old 32MHz synthesizer board in the Mark 4 formatter was replaced with the current design between sessions 1 and 2.
• The Mark 4 formatter had the new PROMS installed between sessions 1 and 2. Test observations before the session (S01C2) showed that the formatter worked.
• A Mark 4 decoder was installed immediately after session 2. Initial tests show that is recognized by the field system, but that many of the additional capabilities of the hardware (phasecal extraction etc.) are not yet supported in software.
• A new phasecal injection unit was installed at the apex of telescope number 7 (RT7) just before session 2. This unit is very much based on the standard geodetic phasecal unit, but has an onboard microprocessor for temperature control, switching on/off, and for setting attenuation. A small local field system program controls it.
• Initial tests are starting on the new IF (IF to Video Converter or IVC) and initial (minimal) version adding system (TiedArray Distribution Unit minimum or TADUmin). This is needed for 8x16MHz bandwidths with the tied array. These tests go in parallel with commissioning the DZB correlator needed for phase and delay control.
• After buying a new Spin Physics headstack, spare parts are again up to the minimum list suggested by Burgess

Operational

• Some testing of 2 headstack recording has started

Software

• Work continues on the TMS (Telescope Management System) software to improve reliability, and particularly the alarm and warning system.

Geodesy