Galileo service is currently degraded, see:
https://www.gsc-europa.eu/notice-advisory-to-galileo-users-nagu-2019025
Martin
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Chris,
i have one which I bought new several years ago. It had a failure under
warranty where in the serial chip stopped doing its thing. The unit continued
to lock to SVs and delivered 10MHz and the PPS. Took almost two months to be
returned, where it worked fine until very recently. Same
Dave wrote:
>I have recently assembled some reasonably low temperature coefficient (5
ppm/deg C) resistors in a reasonably well insulated box to try to make a
resistor that should be stable over short time periods to allow it to be
used as a transfer standard. But I am seriously >considering
In message <009b66fe-c0b0-4f80-8a79-4a487dcb0...@yahoo.com>, Demetrios Matsakis
via time-nuts writes:
> Demetrios Matsakis, as of this Saturday a USNO retiree, and as of August 1 a
> consultant for Masterclock.
Do Time Lords get to keep their TARDIS in retirement ?
Best wishes for
Hi John,
That repair cost is enough to steer me away from buying one. I have a
mediocre view of the sky with my current antenna setup.
I'll continue on and research some additional possibilities for a GPSDO
unit. Thanks for sharing your experience with the Thunderbolt E unit.
Chris
On
From: Bob kb8tq
- high-Q crystals require SC-cut
>>> ... An SC has a lower Q than an AT of similar size
>>> and design up to the point acoustic Q losses completely take over.
>>> If you are talking about sub 20 MHz OCXO?s with ?doable? crystal
>>> package sizes, the AT will have the
The HP Journal article (page 20 March 1981 issue) on the 10811A agrees with Bob.
It also points out that the lack of activity dips due to coupled modes and a
much smaller dependence of the frequency on the signal level are advantages of
the SC cut compared to the AT and BT cuts.
Bruce
> On 13
In message
, "Dr. David Kirkby" writes:
>I partially read the paper mentioned. I note that the authors used a thermo
>electric cooler (TEC) as they wanted get low temperatures.
Cooling GigaOhm resistors makes sense, Johnson/Nyquist noise is
proportional to the product of absolute
In message <2573d544-e3c9-4810-95c9-9e3a468ed...@leobodnar.com>, Leo Bodnar wri
tes:
>Here is a random selection of links to back my point of view that,
>if you have noticed, contradicts Bob's.
Given that quartz resonators is still both science and art, I put
my money on the guy who
Hi
Here’s the gotcha with what they are talking about. The SC when done as a
*fundamental* crystal has a higher Q than the AT. You don’t use fundamental
mode SC’s in a normal OCXO.
The issue with Q relates very specifically to the sort of HC-40 package AT
resonators
you *would* use for
Hello,
A TEC is good if you want to maintain the resistors at 25ºC, that seems
the zero TC point for some precision low TCR resistors (for example, the
Vishay VFCP or VSMP series)
Regards,
Javier
On 12/7/19 10:06, Dr. David Kirkby wrote:
On Fri, 12 Jul 2019 at 08:07, Bernd Neubig wrote:
On Fri, 12 Jul 2019 at 20:02, Bob kb8tq wrote:
> Hi
> If you do go the TEC route, plan on a fairly big power source :). There is
> a
> Wenzel doc on doing a TEC based enclosure using a couple of die cast
> boxes. The pictures don’t show what they used to drive the beast so part
> of
> it would
> Galileo service is currently degraded, see: https://www.gsc-europa.eu/
> notice-advisory-to-galileo-users-nagu-2019025
Thanks.
Is anybody monitoring a Galileo-only setup to see how far off the timing
drifts?
--
These are my opinions. I hate spam.
Hi
If you do go the TEC route, plan on a fairly big power source :). There is a
Wenzel doc on doing a TEC based enclosure using a couple of die cast
boxes. The pictures don’t show what they used to drive the beast so part of
it would still be up to you. My search skills and their web site are
And if you are not in a well air conditioned room
Gilles.
Envoyé de mon iPad
> Le 12 juil. 2019 à 18:12, Javier Herrero a écrit :
>
> Hello,
>
> A TEC is good if you want to maintain the resistors at 25ºC, that seems the
> zero TC point for some precision low TCR resistors (for example,
drkir...@kirkbymicrowave.co.uk said:
>> If you do go the TEC route, plan on a fairly big power source :).
> I'm particularly keen to avoid the requirement for high power, as I was
> thinking to make this in such a way it can be shipped and powered up all the
> time. If it could run from a few
It seems to more than a little "degradation". My F9T is seeing and tracking
Galileo sats, but is not using the results for navigation... Lady Heather shows
all Galileo sats in yellow. Selecting Galileo only, the receiver reports it
is attempting to acquire satellites and not producing a
Hi
Airlines tend to have issues with various battery types as well. Not clear
what the rules are on “powered up in the hold” are. My guess is that ground
transportation gets the nod pretty quickly.
TEC’s are good for some limited temperature delta and then you need to go to
cascaded “layers”
I built this website as my senior design project last year, unfortunately
there's no timing data (except for tdop) being logged but you can see the
impact. Data is collected with four ublox m8n receivers, one per
constellation.
Galileo data from last 1 week:
Hi
Ok, if it’s a “heat only” design, how about a dewar flask? They aren’t the most
rugged items
out there so some sort of padded enclosure would be needed. The real question
is:
Does a “single end” design impact your ability to use the resistor? Put another
way - do you need
to hit both ends
Looking at the data it seems that GPS is the best system among the four,
correct?
Luciano
Da "time-nuts" time-nuts-boun...@lists.febo.com
A "Discussion of precise time and frequency measurement"
time-nuts@lists.febo.com
Cc
Data Fri, 12 Jul 2019 18:29:10 -0400
Oggetto Re:
Figure 5 in http://www.wenzel.com/wp-content/uploads/Sub-pico-Multiplier.pdf
??
Bruce
> On 13 July 2019 at 05:23 Bob kb8tq wrote:
>
>
> Hi
>
> If you do go the TEC route, plan on a fairly big power source :). There is a
> Wenzel doc on doing a TEC based enclosure using a couple of die cast
>
Hi
The “thermoelectrc chamber” in that paper *is* the gizmo. There is / was a
better paper
diving into the unit in a bit more detail. Even that did not get down to issues
like the controller,
the driver, or the power consumption. Indeed one wonders if there is a giant
heatsink and fan
on the
On Fri, 12 Jul 2019 at 22:02, Hal Murray wrote:
>
> drkir...@kirkbymicrowave.co.uk said:
> > If it could run from a few NiMH cells for 48 hours, that would give the
> > option of shipping it. I don't know if that's going over the top, but it
> > would be an interesting exercise.
>
> Shipping a
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