Re: [time-nuts] Hydrogen maser frequency jumps

[Azelio Boriani]

How are related the three locations' jumps? Do they occur at the same
time? One more than the others?

On Sat, Dec 5, 2015 at 11:45 AM, Poul-Henning Kamp  wrote:
> 
> In message 
> 

Re: [time-nuts] Hydrogen maser frequency jumps

[Magnus Danielson]

Jim,

On 12/05/2015 11:45 AM, Poul-Henning Kamp wrote:


In message 

Re: [time-nuts] Hydrogen maser frequency jumps

[Tom Van Baak]

Jim,

Check IF level and H2 pressure. Also see if OCXO tuning is near a rail. Go back 
through the past month and look at trends on all the parameters. You are 
logging all channel data, I hope.

Also check your microwave ovens: http://arxiv.org/pdf/1504.02165v1.pdf  ;-)

Less technical links:
http://www.nature.com/news/microwave-oven-blamed-for-radio-telescope-signals-1.17510
http://www.skyandtelescope.com/astronomy-news/microwave-ovens-spark-radio-signals-peryton-05122015/
http://phenomena.nationalgeographic.com/2015/04/10/rogue-microwave-ovens-are-the-culprits-behind-mysterious-radio-signals/

/tvb


> Has anyone here who is familiar with hydrogen masers ever experienced a
> sudden jump in phase of the 5MHz output?
> 
> We have found they occur semi-regularly (few times a week) and are trying
> to find a culprit.
> 
> The weird thing is that the jump is ~0.7ns and that 1/0.7E-9 is close-ish
> to 1420.4MHz which is the hydrogen line. Too much of a coincidence for me.
> 
> These seem to be appearing at three different locations with the same model
> of maser at each location. I won't mention the model publicly.
> 
> We're still investigating various potential causes (e.g. power spikes,
> cables being moved), but this 0.7ns figure is niggling me.
> 
> Has anyone here ever seen such a thing before?
> 
> 
> Jim

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Re: [time-nuts] Hydrogen maser frequency jumps

[Attila Kinali]

On Sat, 5 Dec 2015 12:16:44 +1100
Jim Palfreyman  wrote:

> Has anyone here who is familiar with hydrogen masers ever experienced a
> sudden jump in phase of the 5MHz output?
[...]
> The weird thing is that the jump is ~0.7ns and that 1/0.7E-9 is close-ish
> to 1420.4MHz which is the hydrogen line. Too much of a coincidence for me.
> 
> These seem to be appearing at three different locations with the same model
> of maser at each location. I won't mention the model publicly.

You should at least say what kind of maser it is and what the
synthesis chain looks like. Otherwise it will be only wild guesses.

If you have an active maser, then it is most likely that you have
a cycle slip due to weak signal (or low SNR), as PHK has written.

If it's a passive maser, that explanation doesn't work, as the
synthesis chain works the other way round (loosely speaking)
and uses an FLL on the atomic transition.

Attila Kinali
-- 
It is upon moral qualities that a society is ultimately founded. All 
the prosperity and technological sophistication in the world is of no 
use without that foundation.
 -- Miss Matheson, The Diamond Age, Neil Stephenson
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Re: [time-nuts] Hydrogen maser frequency jumps

[Bob Camp]

Hi

> On Dec 5, 2015, at 5:45 AM, Poul-Henning Kamp  wrote:
> 
> 
> In message 
> 

Re: [time-nuts] Hydrogen maser frequency jumps

[Poul-Henning Kamp]

In message 

Re: [time-nuts] Hydrogen maser frequency jumps

[Poul-Henning Kamp]

In message 

Re: [time-nuts] Hydrogen maser frequency jumps

[Brian Inglis]

If microwave ovens could be an issue, could current popular mobile phone/tablet 
(Qualcomm Snapdragon, Samsung Exynos, Apple A7/M7) and low power desktop (Intel 
Core) processors running at nominal 1.4GHz also be an issue?

On 2015-12-05 09:06, Tom Van Baak wrote:

Jim,

Check IF level and H2 pressure. Also see if OCXO tuning is near a rail. Go back 
through the past month and look at trends on all the parameters. You are 
logging all channel data, I hope.

Also check your microwave ovens: http://arxiv.org/pdf/1504.02165v1.pdf  ;-)

Less technical links:
http://www.nature.com/news/microwave-oven-blamed-for-radio-telescope-signals-1.17510
http://www.skyandtelescope.com/astronomy-news/microwave-ovens-spark-radio-signals-peryton-05122015/
http://phenomena.nationalgeographic.com/2015/04/10/rogue-microwave-ovens-are-the-culprits-behind-mysterious-radio-signals/

/tvb



Has anyone here who is familiar with hydrogen masers ever experienced a
sudden jump in phase of the 5MHz output?

We have found they occur semi-regularly (few times a week) and are trying
to find a culprit.

The weird thing is that the jump is ~0.7ns and that 1/0.7E-9 is close-ish
to 1420.4MHz which is the hydrogen line. Too much of a coincidence for me.

These seem to be appearing at three different locations with the same model
of maser at each location. I won't mention the model publicly.

We're still investigating various potential causes (e.g. power spikes,
cables being moved), but this 0.7ns figure is niggling me.

Has anyone here ever seen such a thing before?


Jim


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--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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[time-nuts] Hydrogen maser frequency jumps

[Jim Palfreyman]

Hi all,

Has anyone here who is familiar with hydrogen masers ever experienced a
sudden jump in phase of the 5MHz output?

We have found they occur semi-regularly (few times a week) and are trying
to find a culprit.

The weird thing is that the jump is ~0.7ns and that 1/0.7E-9 is close-ish
to 1420.4MHz which is the hydrogen line. Too much of a coincidence for me.

These seem to be appearing at three different locations with the same model
of maser at each location. I won't mention the model publicly.

We're still investigating various potential causes (e.g. power spikes,
cables being moved), but this 0.7ns figure is niggling me.

Has anyone here ever seen such a thing before?


Jim
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