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lbaops:tidnotes:freqsetup

Frequency Setup

On DSS43 the first LOs are as follows:

L-band : 1380 MHz (for narrow band L→S Up Converter, to be used for L1) L-band : 1325 MHz (for wide band Down Converter, to be used for L1 or L2) S-band : 2000 MHz X-band : 8100 MHz K-band (Old receiver) : Whatever the MMS frequency is set to will appear at 321.4 MHz K-Band (New receiver) : 22000 MHz or 24000 MHz as set with WBDC Ka-band : 31700 MHz

The IF should be mixed to a DAS centre frequency of 160 MHz. Upper sideband mixes are usually used which means the band is flipped at the DAS inputs. The second LO frequency to be selected depends on the DAS profile to be used. Once you know the sky frequency you want mixed to 160 MHz, the formula for calculating the 2nd LO is:

2nd_LO_freq = sky_freq - first_LO_freq + 160 MHz

For example, if we want a L-band frequency of 1650 MHz into the DAS, the 2nd LO to set is 430 MHz for L1 (or 485 MHz for L2). Bandpass filters may be required to avoid aliasing in some cases.

lbaops/tidnotes/freqsetup.txt · Last modified: 2015/12/18 16:39 (external edit)