measurement Cc:
hmur...@megapathdsl.net Subject: Re: [time-nuts] ADEV query Timelab and TICC
t...@leapsecond.com said:
> The TAPR dividers tend not to have "this problem" because they output at
> wimpy TTL/CMOS levels.
Modern CMOS drivers have fast rise times. As long as the ri
t...@leapsecond.com said:
> The TAPR dividers tend not to have "this problem" because they output at
> wimpy TTL/CMOS levels.
Modern CMOS drivers have fast rise times. As long as the rise time is short
relative to the cable length, it gets doubled if the end of the cable is an
open circuit.
>
o.com
A "Discussion of precise time and frequency measurement" time-nuts@febo.com
Cc
Data Mon, 20 Mar 2017 09:48:24 -0700
Oggetto Re: [time-nuts] ADEV query Timelab and TICC
Luciano,
This should not happen with the hp 5065A or 5061B frequency standards. I'm
glad you wo
Date: Sun, 19 Mar 2017 22:09:57 -0700
From: Orin Eman
To: Tom Van Baak , Discussion of precise time and
frequency measurement
Subject: Re: [time-nuts] ADEV query Timelab and TICC
Message-ID:
Content-Type: text/plain; charset="utf-8"
On Sun, Mar 19, 2017 at 8:03 PM, To
Sent: Monday, March 20, 2017 12:56 AM
Subject: Re: [time-nuts] ADEV query Timelab and TICC
>
> All,
> the similar problem I have verified using the HP5065A and HP5061B 1PPS
> output, the dividers are pratically unusable for ADEV measurements. The
> 5/10MHz output of the same ins
That doesn't make much sense if you are using the PICDIV properly... the TAPR
dividers use the PICDIV chip to do the dividing. The only difference between
using a TAPR divider and a bare PICDIV is that the TAPR dividers have an input
squarer circuit and output buffer. If you are feeding the P
; Luciano
> www.timeok.it
>
>
> Da "time-nuts" time-nuts-boun...@febo.com
>A "Discussion of precise time and frequency measurement"
>time-nuts@febo.com
> Cc
> Data Sun, 19 Mar 2017 20:03:29 -0700
> Oggetto Re: [time-nuts] ADEV query Timelab and
using other TIC as The
HP53132A.
Luciano
www.timeok.it
Da "time-nuts" time-nuts-boun...@febo.com
A "Discussion of precise time and frequency measurement" time-nuts@febo.com
Cc
Data Sun, 19 Mar 2017 20:03:29 -0700
Oggetto Re: [time-nuts] ADEV query Timelab
The LTE-Lite User Manual (version 1.3) says:
2.3.7 1 PPS Module outputs
The LTE-Lite SMT Module provides GPS raw 1 PPS CMOS pulse on pin 15 with
sawtooth present, and a clean TCXO-generated, sawtooth-removed, UTC(GPS)
phase-locked 1PPS output on pin 4.
It is the pin 4 output that connects to the
Many thanks for the replies on this, what was initially intended as a quick
"Hello World" test seems to have become far more interesting:-)
I'll forward my results to Tom as requested and see where we go from there.
Nigel
GM8PZR
___
time-nuts maili
On Sun, Mar 19, 2017 at 8:03 PM, Tom Van Baak wrote:
>
> Thanks for the raw data. It's very nice (2 hours 16 minutes = 8219
> points). Everything looks fine with the exception of 8 glitches. These are
> sometimes obvious jumps in phase, which cause massive spikes in frequency.
> Two plots attache
Yes, programs like Timelab and Stable32 are definitely the way to go for
post-processing and analyzing your data in depth. Lady Heather is more of a
real-time monitoring and data acquisition program.
The sensitivity of ADEV to data hiccups can be a good thing. If your ADEV data
goes to c
Orin sent me his data files and I ran them through Lady Heather. Attached is a
screen dump showing the Time Interval Error (TIE) plot of the 1PPS signal.
This is the deviation of the 1PPS signal from the expected 1 second interval.
Three of the bad points are flagged (1, 2, and 3 at the top
Hi Orin,
More info... If you try to manually remove the 25 ns glitches you get a data
set that looks much better. Attached are the ADEV plots for (1) your raw data
and (2) your data minus those 8 glitches. You can see the dramatic difference
that just 8 points make. Blue is raw data, red is dat
: Discussion of precise time and frequency measurement
Sent: Sunday, March 19, 2017 10:04 PM
Subject: Re: [time-nuts] ADEV query Timelab and TICC
> I have sent a couple of files to Tom. They were taken simultaneously from
> an LTE Lite - one from the PPS and one from a PicDiv dividi
> I have sent a couple of files to Tom. They were taken simultaneously from
> an LTE Lite - one from the PPS and one from a PicDiv dividing the 10MHz to
> 1Hz. The glitches were on the PPS trace, but not on the PicDiv trace, so
> I'm fairly confident the TICC was working correctly.
>
> Orin.
Hi
t; Of Tom McDermott
> Sent: Sunday, March 19, 2017 15:00
> To: Discussion of precise time and frequency measurement
> Cc: gandal...@aol.com
> Subject: Re: [time-nuts] ADEV query Timelab and TICC
>
> I had this happen this morning. (Running Windows 10). Had 7
> hours of good
>
I saw a similar higher-than-expected ADEV from another user who was measuring
GPSDO PPS vs. 10 MHz from the same GPSDO. Using a T2-Mini from the 10 MHz
yields the expected results.
I suspect that the GPSDO PPS in that unit is derived from GPS PPS rather than
the OCXO, and thus is noisier in t
On Sun, Mar 19, 2017 at 3:00 PM, Tom Van Baak wrote:
> > I've seen similar with my TICC when observing a PPS - can't remember
> > whether the PPS was from the Thunderbolt or LTE Lite.
> >
> > There was a distinct glitch on the frequency plot when it happened and it
> > was pretty easy in timelab
I had this happen this morning. (Running Windows 10). Had 7 hours of good
data
running overnight, (good ADEV, Freq Diff plots).
Then There was a big pop' in the frequency difference trace. ADEV messed up
suddenly.
It happened coincident with starting up Microsoft Edge (which had not been
run
sinc
> I've seen similar with my TICC when observing a PPS - can't remember
> whether the PPS was from the Thunderbolt or LTE Lite.
>
> There was a distinct glitch on the frequency plot when it happened and it
> was pretty easy in timelab to expand the trace around the glitch to take a
> better look.
Hi
It’s a pretty good bet that the “upper” trace has a noise pop in it. One of the
wonderful things about ADEV is that a single
noise event can impact the whole curve. That is a bit non-intuitive. It is
indeed how the math works and how the testing
comes out in the real world.
Bob
> On Mar
anyway.
> You may also want to play around with the averaging value (command 'g').
>
> /tvb
>
> - Original Message -
> From: "GandalfG8--- via time-nuts"
> To:
> Sent: Sunday, March 19, 2017 9:08 AM
> Subject: [time-nuts] ADEV query Timelab a
with the averaging value (command 'g').
/tvb
- Original Message -
From: "GandalfG8--- via time-nuts"
To:
Sent: Sunday, March 19, 2017 9:08 AM
Subject: [time-nuts] ADEV query Timelab and TICC
> Yesterday I used one of John's excellent TICC modules for the firs
Yesterday I used one of John's excellent TICC modules for the first time
and initially set up a quick test using the 10MHz output from a Thunderbolt
as the frequency reference to measure the 1PPS from an Oscilloquartz Star4
GPSDO, with the TICC output feeding a USB3 port on a Windows 10 PC r
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