With the systematic use of inclinometers the telescope pointing became
much more stable. Pointing sessions are now scheduled at larger intervals.
The fitted pointing parameters typically yield an absolute rms
pointing accuracy of better than [10]. An effort is
made that receivers are closely aligned.
Checking the pointing, focus, and receiver alignment is the
responsibility of the observers (use a planet for alignment checks).
Systematic (up to 0.4 mm) differences between the foci of various receivers
can occasionally occur.
In such a case the foci should be carefully monitored and a compromise value
be chosen. Not doing so may result in broadened and
distorted beams ([1]).