Oh boy Chris, some good information there. I guess my first step would be to
get a GPS disciplined source. My preference would be to use an external 10 MHz
source. And even if I did, I'd lose it some times of day depending on
propagation. Maybe the 1 pps to set my OCXO as close as I can get
"I logged NMEA from three cheap ($15-$50) GPS/1PPS receivers, the kind
popular with hobbyists: parallax(good), reyax(good), adafruit(bad)."
what is the problem with the adafruit board?
73
KJ6UHN
Alex
On 7/1/2015 4:34 PM, Kasper Pedersen wrote:
On 07/01/2015 05:23 PM, Tom Van Baak wrote:
I log
Hi
If it’s a GPSDO with a long time constant, the ADEV in the 1-10 second range
should be pretty much “all OCXO” and very
little influenced by the GPS.
Already that makes a bunch of assumptions that may or may not be true:
1) The GPSDO *has* an OCXO and it’s properly designed
2) The unit has
> Okay that makes some sense. I will have to ponder over this and see how it
> will help.
> But in any case (which I sort of expected) it's a time consuming procedure,
> during which the counter isn't available for other use.
Bob, I suspect you don't quite have it yet.
Make one measurement today
Hi
Take your OCXO and divide it down to 1 pps.
Take the PPS out of your GPSDO
Feed both of them into your counter
Time the “delta” between the two to the resolution of a 40 year old 5335 ( low
ns).
Wait 10 seconds
Repeat
You now have data to a resolution of ~2x10^-10
Shut down the counter, go
At 07:15 AM 7/1/2015, J. L. Trantham wrote:
Interestingly, the time is 23:59:60 but the UTC ofs is still 16.
I guess it increments to 17 at the end of that operation, i.e., at 00:00:00.
I just pulled the next screenshot to check, and you're correct:
https://www.n5tnl.com/time/leap_2015/tbolt_
At 09:23 PM 6/30/2015, Tom Van Baak wrote:
That's a nice WWVB result. Yes, the triple marker pulse looks is
correct for a positive leap second. What did you use for a receiver?
The receiver module and ferrite bar antenna from a Westclox 70026
desktop 'atomic clock', as available from Walmart
On 07/01/2015 05:23 PM, Tom Van Baak wrote:
> I logged NMEA from three cheap ($15-$50) GPS/1PPS receivers, the kind popular
> with hobbyists: parallax(good), reyax(good), adafruit(bad).
>
> 3) Adafruit Ultimate GPS Breakout
> http://www.adafruit.com/products/746
>
> If someone else has dat
Hi,
Does anyone have any data / a feel for how ... antenna delay accuracy and/or
elevation mask and/or hold position accuracy ... translate to frequency
accuracy for short term measurement i.e. in the 1-10s tau range? That is, which
should I focus on, which not?
Kind Regards, Alan
Okay that makes some sense. I will have to ponder over this and see how it
will help. But in any case (which I sort of expected) it's a time consuming
procedure, during which the counter isn't available for other use. And when I
go to bed I won't know the next day if I might have missed a cou
So I can measure the time interval, which should be one second. If I measure
10 intervals, my resolution would be 1 part in 10 million. I think I can set
the master oscillator closer than that with beating against WWV. So maybe
buying a 1 pps source won't improve anything for me.
On W
J. L. Trantham kirjoitti:
Interestingly, the time is 23:59:60 but the UTC ofs is still 16.
I guess it increments to 17 at the end of that operation, i.e., at 00:00:00.
That is exactly how it should be.
See my video of 2012 leap sec:
https://www.youtube.com/watch?v=DbvMZikqtI4
--
73s!
Esa
OH4K
> As expected, on the leap second the display on the 8183 showed 6:59:60 (the
> 8183-A showed 23:59:60), but the TV400 displayed 7:00:00 at that moment.
> The TV400 remained one second ahead until it displayed 7:00:03 for a two-
> second period, then from 7:00:04 forward it was properly synced.
O
On Wed, July 1, 2015 12:55 pm, Bob Albert via time-nuts wrote:
> I am missing something here. How does one use a 1 PPS signal?
> I see how I can use a 1 MHz or 10 MHz for a time standard but
> the 1 PPS usage eludes me.
Actually you have it backwards. A 1MHz or 10MHz can be a frequency
standard
time-nuts@febo.com said:
> I am missing something here. How does one use a 1 PPS signal? I see how I
> can use a 1 MHz or 10 MHz for a time standard but the 1 PPS usage eludes
> me. Unless the pulse is extremely sharp, a minor uncertainty in the shape
> or amplitude will have profound effects on
subscripti...@burble.com said:
> My linux boxes also did a double 59:
> Wed Jul 1 00:59:58 BST 2015
> Wed Jul 1 00:59:59 BST 2015
> Wed Jul 1 00:59:59 BST 2015
> Wed Jul 1 01:00:00 BST 2015
> Wed Jul 1 01:00:01 BST 2015
That's to be expected (unless you have fancy software).
Internally, Li
Hi Bob,
For precise timing we use the 1PPS output of a GPS receiver. And yes, it is
typically extremely sharp and precise. If you want 1 MHz or 10 MHz then you
need all the complication of a disciplined oscillator. But the timing itself
comes from the receiver's 1PPS pulse. Even without accurat
Hi Bob,
For precise timing we use the 1PPS output of a GPS receiver. And yes, it is
typically extremely sharp and precise. If you want 1 MHz or 10 MHz then you
need all the complication of a disciplined oscillator. But the timing itself
comes from the receiver's 1PPS pulse. Even without accurat
t...@leapsecond.com said:
> Am I reading this right -- those GPS receivers applied the leap second 16
> seconds before they were supposed to, resulting in a double 23:59:44 instead
> of 23:59:59 and 23:59:60? So not only did they use GPS instead of UTC but
> the opted for the double second instead
On 01/07/2015 16:23, Tom Van Baak wrote:
3) Adafruit Ultimate GPS Breakout
http://www.adafruit.com/products/746
This GPS receiver appeared to mess up the 2015 leap second, with a double 5959
and possible receiver reset:
(I also had serial communications issues with this board today)
If s
I am missing something here. How does one use a 1 PPS signal? I see how I can
use a 1 MHz or 10 MHz for a time standard but the 1 PPS usage eludes me.
Unless the pulse is extremely sharp, a minor uncertainty in the shape or
amplitude will have profound effects on the timing.
I use an HP 5328A
On 6/30/2015 10:21 AM, cdel...@juno.com wrote:
Yes, same workbench and location!
How about some of the 5065A owners helping out in a bigger sample?
What I thought is that say on July the 4th a few owners measure their
frequency offset to say at least 5X10-12th and then without changing the
C-fi
Hi Hal,
Am I reading this right -- those GPS receivers applied the leap second 16
seconds before they were supposed to, resulting in a double 23:59:44 instead of
23:59:59 and 23:59:60? So not only did they use GPS instead of UTC but the
opted for the double second instead of a valid leap second
I logged NMEA from three cheap ($15-$50) GPS/1PPS receivers, the kind popular
with hobbyists: parallax(good), reyax(good), adafruit(bad).
1) Parallax PAM-7Q GPS Module
https://www.parallax.com/product/28509
When I powered up this board, I see:
$GPTXT,01,01,02,u-blox ag - www.u-blox.com*50
Good job Arthur and it makes sense since the wwvb clock simply checks every
24 hours it would continue on the old time and GPS updates instantly.
Nicely done.
Regards
Paul
WB8TSL
On Wed, Jul 1, 2015 at 12:34 AM, Arthur Dent
wrote:
> Here is a short video of the leap second compared to a regular
Scott Newell writes:
>
> My linux parallel port WWVB 'scope got a bit confused at the leap
second:
>
>
I have coded a WWVB receiver according to the published standard. It is
all homebrew with an embedded processor and disciplined OXCO.
I did not do any display shots (didn't think anyone wo
Hi
> On Jul 1, 2015, at 6:25 AM, Martin Burnicki
> wrote:
>
> Bob Camp schrieb:
>> Hi
>>
>> So are we all still here? Any portion of the group blasted into
>> non-existance by the leap second please speak up :)
>>
>> ===
>>
>> Any observations of anomalous behavior yet?
>
> From a NVD8C-CSM
My NTP server did a double 59 on the terminal. for anybody who is interested
I captured the event :
https://youtu.be/OpNci29CI7E
I did measure an odd behaviour on leapsecond day from time-a.nist.gov NTP server
usually it runs about 8 mS behind my local PPS but all the sudden went
to +22 mS for
most
Interestingly, the time is 23:59:60 but the UTC ofs is still 16.
I guess it increments to 17 at the end of that operation, i.e., at 00:00:00.
Joe
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Scott Newell
Sent: Tuesday, June 30, 2015 7:29 PM
To: tim
> Le 1 juil. 2015 à 09:02, Hal Murray a écrit :
>
>
> michael.c...@sfr.fr said:
>> Lady Heather just went told me 23:59:59 , 00:00:00 and stayed there for 2
>> secs, No 23:59:60 :-(
>
> What sort of device was it looking at?
>
a T-Bolt. Firmware 3.0 GPS 10.2 .Mfg. 2002. Leap status was "Lea
Oddly enough I do have a PPS output from the TCXO I was measuring. It's on
a little board I made and there is a PicDiv right on it. I'll have to play
around with that.
I did notice the aliasing issue trying to measure a 12MHz crystal. It
appeared to have incredible stability and accuracy for a pla
Bob Camp schrieb:
Hi
So are we all still here? Any portion of the group blasted into non-existance
by the leap second please speak up :)
===
Any observations of anomalous behavior yet?
From a NVD8C-CSM v3.1 module in Glonass-only mode:
$GPZDA,235958.00,30,06,2015,00,00*65
$GPGGA,235959.00,
At home I recorded the following seconds:
Tunderbolt GPSDO 58 59 60 00 01 02
Meinberg LANTIME M200 58 59 59 00 01 02
hopf DCF 7001 58 59 60 01 02 03
Conrad DCF Time Terminal 58 59 00 01 02 03
The (old 1999) DCF hopf clock in particular was a strange one. It
announced a
time-nuts@febo.com said:
> As expected, on the leap second the display on the 8183 showed 6:59:60 (the
> 8183-A showed 23:59:60), but the TV400 displayed 7:00:00 at that moment. The
> TV400 remained one second ahead until it displayed 7:00:03 for a two-second
> period, then from 7:00:04 forward it
michael.c...@sfr.fr said:
> Lady Heather just went told me 23:59:59 , 00:00:00 and stayed there for 2
> secs, No 23:59:60 :-(
What sort of device was it looking at?
--
These are my opinions. I hate spam.
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