Figure 2.1 compares the continuum and line
sensitivity of the current instrument to that we expect to achieve
with the . We assume a maximum usable bandwidth with RFI excision
at the lower frequencies, and add an atmospheric and galactic
contribution to the system temperature, assuming a typically dry
atmosphere, and (for the low frequency cases), observations away from
the galactic plane. The system temperature assumes new, modern
receivers, employing cooled polarizers (the ``VLBA design'') and new,
wide-band feed horns. The values for the receiver and system
temperatures, efficiency, and bandwidth used for the calculation of
the upgraded sensitivity are shown in Table 2.3.
The listed bandwidth is the sum of the orthogonal polarizations, and
the quoted sensitivity is 
for a 12-hr observation.
| Band Name | Frequency |  |  |  |  |
| (GHz) | (K) | (GHz) | |||
| .240 | 135 | 0.40 | .10 | 36 | |
| .370 | 80 | 0.40 | .10 | 21 | |
| .825 | 58 | 0.40 | .50 | 8.6 | |
| L | 1.42 | 28 | 0.55 | 1.0 | 1.7 |
| S | 3.0 | 29 | 0.62 | 3.0 | 0.88 |
| C | 6.0 | 31 | 0.60 | 6.0 | 0.68 |
| X | 10.0 | 34 | 0.56 | 6.0 | 0.79 |
| U | 15 | 39 | 0.54 | 8.0 | 0.82 |
| K | 23 | 54 | 0.51 | 12.0 | 0.98 |
 | 34 | 45 | 0.39 | 16.0 | 0.92 |
| Q | 43 | 66 | 0.34 | 10.0 | 2.0 |