22GHz water maser W49: a star birth cluster.

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Michiel Klaassen

Jun 1, 2022, 6:33:45 AM6/1/22
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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



Jun 1, 2022, 11:51:55 AM6/1/22
to Camras-forum
Hoi Michiel,

Wat een prachtig resultaat! 
Toevallig heb ik op 28 mei ook een spectrum van W49 gemaakt, uiteraard is er meer ruis omdat het met een veel kleinere 1 meter schotel is gemaakt maar desondanks komen onze resultaten zeer goed overeen.
Overigens ben ik de laatste tijd bezig geweest met de correctie van de frequentiedrift en -afwijking van de DRO LNB doormiddel van een stabiel referentiesignaal (gegenereerd met een GPSDO), maar daarover later meer : )

Vriendelijke groet, 

Michiel Klaassen

Jun 1, 2022, 2:30:32 PM6/1/22
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Hi Eduard

This is truly amazing; our results match exactly, The photons we receive are different but each were generated 36,000 light years away from the same spot. This is indeed a full circle connection.

The stability of our measurements indeed are not very stable and here in Portugal the temperature swing is even greater.
I also tried adding a pilot tone, and I saw that it was swaying 1MHz over the spectrum range. So compensating that with my phyton script is not impossible, but not easy.
I have done tests with some RF generators, but they do not all generate an overtone high/strong enough. In the end the one I use now is this one:

Ltdz MAX2870 STM32 23.5-6000Mhz Signaal Bron Module Usb 5V Aangedreven Frequentie En Modi Accessoire
30 euro

The weather here is still not suitable for observations; strong winds and rain/clouds.


Ps; I modified the LNB ;so the output frequency is now 1.5GHz; no need for a special dongle

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