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Electronics => Metrology => Topic started by: 5065AGuru on October 19, 2021, 06:18:42 pm

Title: Passive Hydrogen Maser teardown!
Post by: 5065AGuru on October 19, 2021, 06:18:42 pm
Just added "update 5" to http://www.leapsecond.com/maser/ (http://www.leapsecond.com/maser/)

It gives details on "digging down" to the cavity of the Maser.

Lots of PIX!  :)

Cheers!

Corby
Title: Re: Passive Hydrogen Maser teardown!
Post by: 5065AGuru on November 16, 2021, 02:08:53 am
Just added "update 6" to http://www.leapsecond.com/maser/ (http://www.leapsecond.com/maser/)

It gives details on removing and opening  the cavity of the Maser.

Lots of PIX!  :)

Here is the "eye candy" shot of the storage bulb! :popcorn:
[attachimg=1]

Cheers!

Corby
Title: Re: Passive Hydrogen Maser teardown!
Post by: dietert1 on November 16, 2021, 09:10:39 pm
Your interesting pictures reminded me of my last physics project. That was building an infrared optical frequency standard using a CO2 laser stabilized by a large OsO4 absorption cell, at 30 THz. The project was abandonded without completion after in 1989 the physics nobel prize went for the development of atomic traps.
Funds got redirected to trap research. Guess there are results by now.

https://www.youtube.com/watch?v=1JBHG6fipr4 (https://www.youtube.com/watch?v=1JBHG6fipr4)

Regards, Dieter
Title: Re: Passive Hydrogen Maser teardown!
Post by: ch_scr on November 17, 2021, 09:42:53 am
That video had nice glory shots of the laboratory  :popcorn:
For a more in depth technical presentation, I can recommend this from the same researcher,
https://www.youtube.com/watch?v=NbJ2rWUbrhk (https://www.youtube.com/watch?v=NbJ2rWUbrhk)
held at the BIPM conference regarding the redefinition of the SI constants (26th CGPM)
Title: Re: Passive Hydrogen Maser teardown! (update 7)
Post by: 5065AGuru on February 03, 2023, 11:19:55 pm
Find update 7 here:

http://www.leapsecond.com/maser/UPDATE7.pdf (http://www.leapsecond.com/maser/UPDATE7.pdf)

Cheers,

Corby
Title: Re: Passive Hydrogen Maser teardown!
Post by: notfaded1 on July 21, 2023, 12:33:48 pm
Sweet Corby... I missed this!  It's been busy at work.  Any recent updates?

Bill
Title: Re: Passive Hydrogen Maser teardown!
Post by: rubidium on July 21, 2023, 06:04:41 pm
Rather amazing work! You gotta have real stones to take on an effort like this!  :box:
Title: Re: Passive Hydrogen Maser teardown!
Post by: 5065AGuru on July 21, 2023, 06:28:55 pm
After some work, including adding an oven to the vacuum chamber, I was able to take some measurements.
Unfortunately For some reason I cannot get the cavity to tune properly at vacuum and at the correct temperature. Seems like the loaded cavity arrangement is very sensitive to changes. I did evaluate several new varactors and could get a proper range of tuning but the center frequency could not be obtained! :)
Put the project to the side for a bit to regroup.

Cheers,

Corby