This receiver, operating with a Millitech Schottky mixer, is installed in line with the 4th mirror, behind the polarization rotator. It can be used simultaneously with either the 2 mm (or 230G2) receiver or a guest receiver.
The Continuum receiver can only be used for pointing. Continuum
sources of 
0.8 Jy (at 86 GHz) can be used for pointing checks;
there are approximately 120 continuum sources catalogued. The
Continuum receiver is normally aligned within 2
of the other
receivers.
Figure: Performance of the 3mm SIS receiver
Figure: Performance of the 2mm SIS receiver