Hartebeesthoek (Hh) Station Report - TOG Meeting - September 2008 Session I - February/March 2008: This was a very busy session for us, despite only some 14 experiments being recorded, of which 10 were user experiments, comprising some 94% of the 120 hours (42 hours L-band, 28 hours S/X-band, 22 hours C-band and 28 hours Methanol) of recording time, and some 90% of the 20216 Gbytes of recorded Mark5A data. The average filling factor of the disk-packs was about 95% despite a split of 2 and 12 experiments being destined for the Socorro and JIVE correlators respectively. Two experiments comprising about 10 hours (i.e. 8%) of data were impacted by a L-band cryogenics failure. We also experienced our usual L-band RFI problem. Session II - May/June 2008: The next session was even busier with a total of 21 experiments being recorded, of which 15 were user experiments, comprising some 84% of the 146 hours (7 hours K-band, 58 hours L-band, 34 hours C-band and 47 hours Methanol) of recording time, and some 91% of the 25046 Gbytes of recorded Mark5A data. The average filling factor of the disk-packs was 95% with all experiments destined for JIVE. Only two minutes (ie. ~0%) of data was lost during the session, due to a local scheduler programming error (since fixed) twice leading to the telescope being late onsource at the start of an experiment. Again significant RFI was experienced throughout the L-band part of the session. Mark5A Recorder: Although we have procured all the components necessary for the conversion of the recorder into a Mark5B, the upgrade awaits confirmation from the correlator that they are able to handle Mark5B recordings. The recorder continues to perform extremely reliably except at 1Gbps where a few scan_checks indicate some byte dropping. Mark 4 Terminal: Similarly components necessary for the conversion of the Mark4 formatter into a VSI sampler suitable for use with a Mark5B recorder have been purchased but not installed, pending the conversion of the Mark 5 recorder itself. No significant repairs/upgrades were done to the terminal over this period. Frequency Standards: HartRAO continues to operate on our new EFOS-C maser (EFOS-28) which has performed flawlessly since its installation over five years ago, with the latest sythesizer re-tuning being done after two year of uninterrupted operation. Our old EFOS-A maser (EFOS-6) is still non-functional, with the replacement of the internal vacion pump still pending. Telescope Surface: There has been no further progress on this issue since the last TOG meeting, holographic mapping of the remaining surface errors has stalled for the moment. Receivers: The only change in our receivers since the last TOG meeting, is the replacement of both of the cryogenice LNAs in the L-band receiver (following the failure of the RCP amplifier a year or two ago) which is in progress right at the moment. Other Hardware/Software: Field System: FS9.10.2 running on FS Linux 7 (Debian "etch") kernel 2.6.18-6 Mark5A version: 2005y147d17h still running on Debian "sarge" kernel 2.4.27-3 Computer (and hence FS) control of the secondary reflector position to enable fast switching between all the available receivers is now operational, with an upgrade to a physical linear position encoder proposed for later this year to eliminate an associated Declination pointing instability. J.F.H. Quick 18 September 2008