This was purchased for observing water masers at LRO. Water masers are natural microwave amplifiers that occur in dense, warm molecular clouds surrounding young stellar objects or evolved stars. The most common transition is the 6_16–5_23 rotational line of water at a rest frequency of 22.23508 GHz, which can be observed with radio telescopes (https://worldcalc.org/water-maser-velocity/).
The Norsat 9000 LDF is able to enable radio astronomy observations up to 22.2 GHz, very close to the 22.23508 GHz of water masers. Eduard Mol has found that he has been able to tune the Norsat 9000 LDF up further, if necessary, by turning a tuning screw located inside the case of the device.
From the Norsat website 14/7/2026, the following gives the specifications for the Norsat 9000 LDF which I was fortunate to be able to find on ebay last year:
https://www.astronomy.me.uk/wp-content/uploads/2026/07/9000L-Spec-Sheet.pdf
https://www.astronomy.me.uk/wp-content/uploads/2026/07/Norsat-LNB-Installation-Manual.pdf
