FOSDEM is an Open-Source gathering once a year in Bruxelles, and
this year there is a track dedicated to time:
https://fosdem.org/2015/schedule/track/time/
Those of you of an european persuassion may find it relevant...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
In that case, it all depends on what you're trying to accomplish. If you're
using WWV or something like that to set the frequency, then the 78L05 should be
fine.
Bob
From: ct1dmk ct1...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent:
I tried something like that once just to discover that the OCXO VFC port
had low impedance, so my voltage divider didnĀ“t behave very well. So i
put an amp op in unitary gain configuration between the two and things
improved a lot. Then I changed the amp op for a DP precision part and
things
Luis
If you have sufficient headroom (input supply 7V or so) why not use a
buried zener reference chip like an LT1027?
These chips also have a noise reduction pin.
Otherwise a lower dropout bandgap reference like an LT1019 or similar
may be useful.
Bruce
On Wednesday, January 07, 2015
The difference between GPS time and UTC (due to leap seconds) is
broadcast in the GPS navigation message[1] so all but the most poorly
designed GPS modules should take care of it and output the correct UTC time.
Henry,
This is not quite true. First, page 18 of subframe 4 is only broadcast
Hi
If you find that your EFC port is low impedance - check it for a bias voltage.
It may well have a pull up resistor to an internal Vref. The intent is that you
simply tune it with a resistance to ground.
Bob
On Jan 6, 2015, at 8:49 PM, Daniel Mendes dmend...@gmail.com wrote:
I tried
The difference between GPS time and UTC (due to leap seconds) is
broadcast in the GPS navigation message[1] so all but the most poorly
designed GPS modules should take care of it and output the correct UTC
time.
I'm not going to get into the mess of unix epoch time. Basically,
it's not a
Charles Steinmetz csteinmetz@... writes:
Actually, I dont want to ask my colledge for help. Everytime ,for
each
guy I ask for help, I need expain the entire system and principle of
a
frequency counter to him. They just keep asking questions instead of
answering mine.
In defense of
Luis wrote:
With a multiturn pot and a 78L05 I can get a 0 to 5V EFC to tune
an OCXO on desired freq. But... maybe other voltage regulators
or other scheme have better temp stability than the old 78L05.
Before I crawl lost in new'ish fancy regulator land does anybody
know the killer
I have a SR TDS12 which apart from name appears to be a PRS10. The ID string
indicates PRS10 and the firmware version is the same as on another PRS10 that I
have. The only differences that I could see at first power up is the that
default config has Lock Mode 2 as opposed to the normal default
Hello!
I would like to buy 4 or 5 Milliren 260-0544-C from Excess Solutions as
it was discussed 22 october 2014, but their shipping rates are really excessive
(127 USD for 4 of them). So I would like to know if there's someone in the US
who can buy them for me and ship them cheaply; eventually if
Tom,
Thanks for the comments ! In my design I am using NMEA as an option to
set initial time on the clock. Its just faster and more convenient than
doing it manually. And in the other (rare) occasions when clock logic
could decide to sync. RTC module time with time received from GPS
module.
Tim,
I was using perl as a tool to calculate UNIX time. As my project based
on STM32 MCU, I have no option to use time libraries. And I dont' think
its applcable for my project. I am thinking what exactly of that UNIX
time is. Looks like its using simple constants, like we have 86400
I think you can see this as a 15 second jump if you watch
a GPS receiver doing a cold start. I mean really cold as in
no memory at all rather than it
t...@patoka.org said:
Exactly ! I saw that behaviour few times.But I was thinking its because of
some very old satelites which knows
Are those not the ones that have no EFC
In a message dated 1/7/2015 3:02:20 P.M. Eastern Standard Time,
erm1ea...@ermione.com writes:
Hello!
I would like to buy 4 or 5 Milliren 260-0544-C from Excess Solutions as
it was discussed 22 october 2014, but their shipping rates are really
Today the Dallas area has been experiencing several eathquakes. The largest
were magnitude 3.2, 3.6, and 3.1 at a depth of around 4km.They happened
around every three hours. I am around 5 miles from the epicenter. They are
strong enough to shake the house quite a bit. The largest put a
I'm not sure there's any computer time package that correctly disambiguates
23:59:59 vs 23:59:60 in UTC timestamps in a general purpose way. Some
software simply rejects 23:59:60 UTC as invalid, some will quietly map it
to 23:59:59 effectively making those two seconds impossible to distinguish.
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