List of non-standard configurations

The following describes details of the non-standard configurations currently available that can be used with any receiver.

• NS_125x2 This is a configuration for 2 x 125 MHz bandwidth identical subsystems, auto-correlation mode, single polarity, channel 1 for all receivers. It's useful if something breaks, as it gives you a second copy!

• NS_250x2 This is a configuration for 2 x 250 MHz bandwidth identical subsystems, auto-correlation mode, single polarity, channel 1 for all receivers. It's useful if something breaks, as it gives you a second copy!

• NS_500x2 This is a configuration for 2 x 500 MHz bandwidth identical subsystems, auto-correlation mode, single polarity, channel 1 for all receivers. It's useful if something breaks, as it gives you a second copy!

• NS_MIX_880125

  This is a configuration for mixed 880 and 125 MHz bandwidth observing centred around the same line. Auto-correlation mode, 2-bit for channel 1 only. Gives a wideband and high resolution view of the same line with any receiver on channel 1. Typical results are shown in Figure 6.

  Note that Frontend needs to be set to line rest frequency - 55.0 MHz for Upper sideband and line frequency + 55.0 MHz for Lower sideband operation. Also the source velocity must be correct.

   

The following are non-standard files that are designed to work with specific receivers. The Frontend frequency and sideband need to be set to the values given in the listing, and the appropriate source velocity needs to be set up. The non-standard setups for specific line observations are summarised in table 2.

• NS_A2OFF_125 This is a configuration for 125 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxA2 with an IF offset of -100 MHz. It should be used when RxA2 has a problem in the upper half of the IF passband, with the receiver tuned to Upper OR Lower sideband.

  NB: the Frontend frequency must be offset by +100 MHz for Upper sideband and --100 MHz for Lower sideband operation.

• NS_A2OFF_250

  This is a configuration for 250 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxA2 with an IF offset of - 125 MHz. It is used when RxA2 has a problem in the upper half of the IF passband. It can be used when RxA2 is in Upper OR Lower sideband.

  Note that the Frontend must be offset from the line frequency by + 125 MHz for Upper sideband and --125 MHz for Lower sideband operation.

• NS_A2OFF_500

  This is a configuration for 500 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxA2 with an IF offset of - 230 MHz. It is used when RxA2 has a problem in the upper half of the IF passband. It can be used when RxA2 is in Upper OR Lower sideband.

  Note that the Frontend must be offset from the line frequency by + 230 MHz for Upper sideband and --230 MHz for Lower sideband operation.

• NS_CH3OH307_125

  This is a configuration for 125 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxB3i only. It is used for observing the CH3OH lines at 304.20835 and 307.16594 GHz.

  It should only be used when RxB3i is in Upper sideband with a Frontend frequency of 307.2121 GHz USB.

• NS_COCS_125

  This is a configuration for 125 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxB3i. It is used for observing the CO 3-2 line at 345.796 and the CS 7-6 line at 342.883 GHz simultaneously. Typical results are shown in Figure 7.

  It should only be used with RxB3i in Upper sideband with Frontend frequency of 345.8647 GHz USB.

   

• NS_COCS_125X2

  This is a text file for observing CO 3-2 and CS 7-6 simultaneously, each with a separate 125 MHz bandwidth subsystem centred on the line. Auto-correlation mode, single polarity, channel 1 for RxB3i only. The CS line goes in the specx X-register and CO in the Y-register It should only be used with RxB3i in Upper sideband with frequency of 345.796 GHz. In Specx, to reduce CS, type change-sideband and set-line-rest 342.883 CO can be reduced directly (but set-line-rest 0.0)

• NS_H2CO365_125

  This is a configuration for 125 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxB3i only. It is used for observing the HCO lines at 365 and 362 GHz.

  It should only be used when RxB3i is in Upper sideband with FE frequency of 365.5747 GHz USB.

• NS_H2COHNC_250

  This is a configuration for 250 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxB3i only. It is used for observing the HCO line at 365 and HNC at 362 GHz.

  It should only be used when RxB3i is in Upper sideband with FE frequency of 365.5233 GHz USB.

• NS_HCNH2CO_125

  This is a configuration for 125 MHz bandwidth, auto-correlation mode, single polarity, channel 1 for RxB3i only. It is intended for observing the HCN 4-3 line at 354.5055 and HCO 515-414 line at 351.768 GHz.

  It should only be used when RxB3i is in Upper sideband with a FE frequency of 354.6620 GHz USB.

  
Table 2: Non-standard configurations for specific lines