The two channels were co-aligned in focus, focal plane, and aperture plane in Grenoble on the antenna range, and no further adjustment was made on the site.
Measurements performed during limited periods of good atmospheric conditions during the initial commissioning, together with later measurements made by the PV staff, give the following results.
Co-alignment of A100 and A230 : 2.5''
Focus of A230 relative to A100 : +0.2 mm.
The focus shift is consistent with a difference of 150mm (M=27.8) at the Cassegrain focus, measured in Grenoble, and resulting from a deliberate compromise between focus alignment and beam quality.
| Receiver |  |  |
| A100 | 0.92 | 0.76 |
| A230 | 0.87 | 0.57 |