====== Heterodyne Systems ======
Instructions for [[observing]].
Heterodyne systems at the CSO permit high resolution spectroscopy in the atmospheric windows from 177 to 920 GHz.
===== Receivers =====
^ Characteristics ^^^^^^^^
^ Receiver ^^ Range ^ IF BW ^ //T//rx ^ Tuning ^ Remarks ^ Status ^
| ::: | ::: | [GHz] | [GHz] | DSB [K] | ::: | ::: | ::: |
| |||||||
| Sidecab | 230 | 177-210 | 4-8 | 40 | auto. | Low freq. subband requires\\ add'l LO filter. Consult staff. | operational |
|:::| ::: | 210-286 | ::: | ::: | ::: | | ::: |
|:::| 345 | 315-380 | 1-2 | 90 | manual | | ::: |
|:::| 460 | 382-532 | 4-8 | 40 | auto. | | ::: |
|:::| 650 | 620-730 | 1-2 | 230 | manual | | ::: |
| |||||||
| Cassegrain | Barney | 300-410 | 4-8 | 50 | manual | | //limited availability// |
|:::| 850 | 810-900 | 1-2 | 350-450 | manual | or Nasymth | //limited availability// |
| |||||||
| | Zrex | 200-290 | 4-12 | 160-50 | manual | aka Frank's receiver | //decommissioned// |
^ Measured Performance ^^^^^^^^^^
^ Receiver ^^ Line ^ Freq. ^ SB ^ //Y// ^ //T//sys ^ //τ//225 ^ ZA ^ Date ^
| ::: || ::: | [GHz] | | | SSB [K] | | [deg] | ::: |
| ||||||||||
| Sidecab | 230 | 12CO(2-1) | 230.5 | Up | | 220 | 0.126 | 15° | 2013-03-05 |
|:::| 345 | 12CO(3-2) | 345.8 | Up | 1.9 | 815 | 0.111 | 33° | 2013-04-04 |
|:::| 461 | 12CO(4-3) | 461.0 | Lo | | 1240 | 0.059 | 17° | 2013-03-06 |
|:::| 650 | ||||||||
| ||||||||||
| Cassegrain | Barney | ||||||||
|:::| 850 | ||||||||
==== Notes ====
* All receivers are single polarization and double side band.
* Measured //T//sys at indicated zenith angle (ZA).
* [[sidecab_rxb]]
* [[.:tuning:barney]]
* [[obstime]] estimate
* [[http://cso.caltech.edu/atm/tuning.html|Receiver tuning diagram]]
* [[calibration]]
* [[http://www.submm.caltech.edu/cso/receivers/|Existing and New Balanced Receiver Development]]
* [[http://www.submm.caltech.edu/cso/receivers/instructions.html|Tuning Instructions]] (Narrow band sidecab and 850 GHz receivers)
* [[http://www.submm.caltech.edu/cso/receivers/beams.html|CSO Beam Efficiency Measurements]]
=== Maintenance ===
* [[cryogenfills]]
===== Spectrometers =====
^ ID ^ //N//chan ^ spacing ^ BW ^Remarks ^
| || [kHz] | [GHz] | |
| |||||
| [[FFTS1|FFTS1]] | 8192 | 61 | 0.5 |tunable across 4-8 GHz IF |
| ::: | ::: | 122 | 1 |::: |
| [[FFTS2|FFTS2]] | 4 x 8192 | 268.6 | 4 x 2 | |
| [[AOS5|AOS5]] | 4 x 2048 | 650 | 4 x 1 |four overlapping sections, 4 GHz usable BW |
* [[FFTS1]] \\ Available with all receivers.
* [[FFTS2]] \\ Only available with the wide band (4-8 GHz) receivers.
* [[AOS5]] \\ Only available with the narrow band (1-2 GHz) 345 GHz and 650 GHz sidecab receivers, the 850 GHz receiver, and the wide band (4-8 GHz) 345 GHz receiver (Barney).