> >You can check this with a hair dryer. Measure the effect
> >of a 10 C rise and then extrapolate back to 0.1 or 0.01C
> >to see what the result of making an oven would buy you.
> One problem with that approach is that crystals that are not intended
> for oven operation are optimized for minimum
> I agree. And I should have clarified - one uses a hair dryer to
> generally heat the ambient air nearby the device in question. You can
> use a thermometer to sense the external or internal case temperature
> to limit the temperature rise to 10 C or something sane. Do not, of
> course, blast the
> Then, I am not sure all GPS receivers actually use their internal
> crystal oscillator in a PLL as the timebase. I have read that some
> work by removing or adding pulses in a discrete fashion rather than
> phase locking, and this offers significant jitter, making the 1 PPS
> only useable to
Poul-Henning Kamp wrote:
> In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>> Didier Juges wrote:
>>
>>> One problem with that approach is that crystals that are not intended
>>> for oven operation are optimized for minimum frequency change over 0-50
>>> or some other "normal" environment te
In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>It would be interesting to see how such an oven performs compared
>to the traditional double oven.
According to a guy at the danish metrology lab, the optimal strategy
is moving as little heat as you can get away with.
They keep most of their
FWIW...
I visited an MoD microwave lab many years ago, and they used to run all
their temperature sensitive stuff on a huge steel table about 3 inches
thick, apparently to minimise the effects of ambient temperature change.
Rob K
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL
Poul-Henning Kamp wrote:
> In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>
>> It would be interesting to see how such an oven performs compared
>> to the traditional double oven.
>
> According to a guy at the danish metrology lab, the optimal strategy
> is moving as little heat as you can
In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>Poul-Henning Kamp wrote:
>> In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>>
>>> It would be interesting to see how such an oven performs compared
>>> to the traditional double oven.
>>
>> According to a guy at the danish metrology lab,
Poul-Henning Kamp wrote:
> In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>> But that brings us back full circle: How do you do an exceptional
>> job of controlling the temperature of a crystal that was designed
>> to operate at 25C?
>
> You put it inside a solid block of copper or alumini
In message <[EMAIL PROTECTED]>, Chuck Harris writes:
>True, but surely you don't think he was talking about kilogram
>artifacts? Last I heard, their weight was invariant with temp.
I think the worry with the kilogram artifact is that temperature
changes might affect the surface and or hydrogen a
On 1/19/06, Hal Murray <[EMAIL PROTECTED]> wrote:
>
> > Then, I am not sure all GPS receivers actually use their internal
> > crystal oscillator in a PLL as the timebase. I have read that some
> > work by removing or adding pulses in a discrete fashion rather than
> > phase locking, and this offe
On Wed, 18 Jan 2006 21:59:12 -0600, Didier Juges <[EMAIL PROTECTED]>
wrote:
>Tom Van Baak wrote:
>
>>
>>
>>>I should be able to improve the receiver performance some by ovenizing
>>>it. I wonder if it would be worth the effort?
>>>
>>>
>>
>>You can check this with a hair dryer. Measure the
Oh yes they do..
Extract from Zyfer CSII Manual.
"In the Time Locked mode the GTF module's output signals and the system's
time are
synchronized to UTC. The 1 PPS output from the GPS receiver is used as
reference to
discipline the module's oscillator and to align the 1 PPS output pulse."
On Thu, 19 Jan 2006 15:07:47 +0100, "Poul-Henning Kamp"
<[EMAIL PROTECTED]> wrote:
>Their suggestion for a cheap environmental chamber is an old
>fridge where you keep the door closed. After some weeks it
>will have reached a stable temperature relative to the room.
Heh. Funny story about that
In message <[EMAIL PROTECTED]>, Matt Ettus writes:
>On 1/19/06, Hal Murray <[EMAIL PROTECTED]> wrote:
>>
>> > Then, I am not sure all GPS receivers actually use their internal
>> > crystal oscillator in a PLL as the timebase. I have read that some
>> > work by removing or adding pulses in a discre
Neon John wrote:
> That thing stayed up there about a year until one day when the news
> chopper's live cam didn't have any blood'n'gore to broadcast. He flew
> around the tower zoomed in on the "handi-talkie" for a few minutes.
>
> The station manager had a cow. He vaguely knew that one of his
>
> To my knowledge, nobody tunes the frequency of the oscillator in their GPS
> receiver.
>
> Matt
>
As far as I know, the Trimble Thunderbolt uses the same 10MHz OCXO
that it disciplines as clock for the GPS receiver.
73 Alberto I2PHD
___
time-n
From: Mike Nolan <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] Making the most of SRS Rb source
Date: Wed, 18 Jan 2006 21:58:00 -0400
Message-ID: <[EMAIL PROTECTED]>
> Hi,
Hi Mike,
Now, considering that I would like to probe a pulsar what would be the typical
gear needed? At what frequency do I p
At 2:05 AM +0100 1/20/06, Magnus Danielson wrote:
>From: Mike Nolan <[EMAIL PROTECTED]>
>Subject: Re: [time-nuts] Making the most of SRS Rb source
>Date: Wed, 18 Jan 2006 21:58:00 -0400
>Message-ID: <[EMAIL PROTECTED]>
>
>> Hi,
>
>Hi Mike,
>
>Now, considering that I would like to probe a pulsar wh
> My main curiosity with the GPS is whether there are other
> stabilization methods employed that would make ovenizing moot.
I don't think so.
Basically, the signal you get out from the radio part of a GPS system has
poor short term stability but great long term stability. If you want good
sh
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