Hi All,
In the past I have been experimenting with DRO equipped LNA's; because they were cheap.
Later these were upgraded to x-tal versions, and again later it was necessary to upgrade again to Gps disciplined oscillators.
Now I start all over again with 22GHz lna's. The first experiments are again with a DRO LNB just like Eduard has done.
Attached the first results of the water maser W49 recorded with a slightly modified Norsat LNB.
Center frequency 22.238138698 GHz, 10 minute integration, 28-05-2022, Sao Giao radio telescope.
When you compare the profile to the measurement of Eduard, then you see a difference in the second peak.
Eduard noticed already that there was a change within 1 month, and now 3 months later the difference is even more. There seems to have emerged an extra peak.
This is the reason why the profs are monitoring these masers years on end like the observations done with the radio telescope in Medicina.
see a long list of papers here:
will be continued
Regards,
Michiel