... The cal value for lbw polB changed on 04dec05. ... The Tsys jump in polB occurred with both diode 1 and diode 2 so the problem was after the switch that selects which diode to send to polB. ... The plots show tsys versus date (.ps) ( .pdf ): . ... Top: Tsys polA vs date. ... All tsys measurements switched to diode 2. 23nov05 ( dashed green ): new diodes installed. 23/25nov05 ( dashed purple ): cal values remeasured. 06dec05 ( dashed blue 1405Mhz to get off of the resonance in polA at 1400Mhz. ...

... 2.3 Data acquisition Spectra generated by the Multibeam correlator contain the usual structure seen in spectra from other H i instruments: a bandpass spectrum which is the sum of the sky , ground and receiver temperatures multiplied by the product of the filters in the receiver chain; superimposed on this is a noise ... Note also that sources extended much beyond ,40 arcmin can be imaged poorly in HIPASS images because of the bandpass sidelobe effect described in Section 3.3. ...