A central bearing load adjustment was performed during the day. A summary by Tomas Chylek is that "the load distribution between the central bearing and the rollers has been kept at 85%/15% of the total antenna weight". The full results can be seen here. CW inclinometry followed :

    Datasets  El Dirn     HST     mean leg temperatures   Humidity
                          start     start   middle   end       %
  ( 20030526  90  cw      10:59      5.0      6.2    6.8      70 )
    20030528  90  cw      16:34     11.5     12.0   12.1      35

All data channels were OK. The resulting CW model is compared with previous CW model -- the one taken on May 26 below :

The new model show larger than usual differences from the previous one, as expected following a CBLA. The new model is merged with the recent (CW-CCW) average to create a new hybrid track model.

• The differences in (F1,F2,F3) for the CW models are described by the rms scatters of (0.68", 0.20", 0.60") c.f. (0.57", 0.53", 0.49") previously.

• Updates have been made to the plots of symmetry and strain gauge data. All looks OK - indeed the symmetry of the antenna is much better for the CBLA, being of lower value than at any time in the last 3 years.

• The hybrid model was installed at 19:40 HST on 28 May 2003.

Allsky Pointing
31 blazars were observed between HST 19:30 and 23:00. They show a strong systematic of the azimuth residual (dS) -vs- Z-enith distance - indicative of a change in the azimuth encoder zero point. They were run through TPOINT allowing all 7 parameters to optimize, and yielded a new model with an expected performance in (daz,del) or (dS,dZ) of (0.8", 1.5"). Subseqeuent observations of 11 blazars with elevations > 22^o yielded (1.0", 1.3").

Also :

• SCUBA focus offsets are (dX,dY,dZ) = (-0.11, -0.17, +0.33), with likely noise errors of 0.1mm.
• A few consecutive measures of 1334-127 as it transitted showed no significant (>0.2") 'transit error' :

        Apparent RA      LST       daz    del
       13 37 50.607  13 33.25483  -6.9   -0.7
       13 37 50.607  13 35.95888  -6.5   -0.9
       13 37 50.607  13 38.64036  -6.8   -0.5
       13 37 50.607  13 41.43383  -6.9   -0.6
       13 37 50.607  13 44.17883  -6.8   -0.4
       13 37 50.607  13 47.02576  -7.5   -0.4
       13 37 50.607  13 50.33563  -7.2    0.4
  

Receiver Collimations
RxA3i was tuned to the CO:2-1 line and was pointed and focussed using IRAS16293-2422. The collimations (daz,del) were (4.2,-0.4) and the focus offsets were (0.09,0.05,0.27). A spectral-line 5-point on NGC6302 gave (-0.6,2.8) - although the strength of the source is not great.
RxB was tuned to the CO:3-2 line and was pointed and focussed using IRAS16293-2422. The collimations (daz,del) were (-2,-9) and the focus offsets were (0.14,-0.04,0.21). A spectral-line 5-point on NGC6302 gave (-6.4,0.3).

The collimation.dat file and the smu.ifl file are updated accordingly, although this work may need repeating following the TMU alignment scheduled for May 29.