Re: [time-nuts] General questions about making measurements with time interval counter.

Hi The most basic issue you are going to run into is that your counter is not high enough resolution / accuracy to give you meaningful data for time intervals under a few hundred seconds. I would focus on improving on that part of things before I went off on a major “test everything”

[time-nuts] General questions about making measurements with time interval counter.

MY AIMS 1) Try to learn about the various statistical tests (ADEV, MDEV etc), and how best to compare oscillators, by making some measurements on various oscillators I have. 2) Investigate the short/medium term stability of the output of various bits of test kit. All are locked to GPS by

Re: [time-nuts] hm H Maser

Hi The obvious question would be: What does it cost to set up a line to make a proper set of spherical Rb cells? Doing this as a glassblowing project is a dead end. You need it properly tooled …. Bob > On Jan 11, 2017, at 7:05 PM, Bruce Griffiths > wrote: > >

Re: [time-nuts] hm H Maser

Angus Read the paper I posted on the current state of the art. ADEV ~ 2E-13/SQRT(Tau) is feasible with large cells and using a laser instead of rubidium lamp.In principle, one can use the same cell to lock the laser to the rubidium absorption line and lock the microwave signal.Suitable laser

Re: [time-nuts] hm H Maser

Hi > On Jan 11, 2017, at 6:07 PM, Angus wrote: > > On Tue, 10 Jan 2017 21:43:07 -0500, you wrote: > >> >> This does get back to “state of the art Rb” and what that means. In my >> suggested case that’s measured in terms of ADEV for Tau = 1 to 1,000,000 >> seconds.

Re: [time-nuts] hm H Maser

On Tue, 10 Jan 2017 21:43:07 -0500, you wrote: > >This does get back to “state of the art Rb” and what that means. In my >suggested case that’s measured in terms of ADEV for Tau = 1 to 1,000,000 >seconds. If you wanted an Rb with (only) state of the art phase noise at 1 MHz >offset … that’s a

Re: [time-nuts] hm H Maser

Hi A spherical set of cells is going to be a massive pain to fabricate. I believe you can hit < 5x10^-12 / sqrt(tau) with a fairly normal cell design and cavity design. There are some very basic issues with the photo detector’s S/N that also tip things towards a coaxial approach. Bob > On

Re: [time-nuts] hm H Maser

Hi A cryo pump will get you into reliability issues if run 24/7. It also is doubtful that you will be able to maintain the vacuum level over long periods. Bob > On Jan 11, 2017, at 12:09 AM, Bruce Griffiths > wrote: > > One could always use a cryo pump. > The

Re: [time-nuts] hm H Maser

In message <619617e1-aa26-4eb7-b73e-042f22912...@n1k.org>, Bob Camp writes: >I guess the question then would be: > >Is a H Maser that runs 6.6 x 10^-12 at 1 second worth the trouble? I would say absolutely not. All things considered, I think a trapped-ion type standard would be both

Re: [time-nuts] hm H Maser

In message <0C641805E0824C499D3C15F67F0B880B@pc52>, "Tom Van Baak" writes: >To keep a maser room within 1 C or 0.1 C takes much more power [...] Forget the power: Look at the installation costs. If you want to be able to go in and pat your maser, the air volume and flow has to be big

Re: [time-nuts] 5ms glitch on WAN ntp server peerstats at around 01:00 UTC today

Hi Dan, Everything seems pretty much back to normal this morning. I’ll have to take another look at yesterdays data to see when that happened. I’ll add a suitable graph to my site as an example of wide area routing induced offset glitches. Mike > Le 11 janv. 2017 à 00:14, d...@drown.org a écrit

[time-nuts] WWVB Simulator

After doing some more design work on my WWVB simulator I came up with a DC way to change output levels from 2 V to 2 uV (p-p). in 20dB steps. That would be at "full power" output. Reduced output will be 17 dB down from that. Well into the weeds at low signal levels. That would be quite some