: [time-nuts] Hanging bridge question
Message-ID: 2674b568-04b1-4ebc-ac6d-d7f4dd347...@rtty.us
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Hi
HP = Hewlett Packard
Bob
On Mar 26, 2014, at 10:31 AM, Matthew Martin dr_g...@yahoo.com wrote:
Hi,
Just a quick question from a novice
In message B92E1A45BB35480FA213DA5F32CEA2BA@pc52, Tom Van Baak writes:
That's only true for time scales less than the cross-over point.
Beyond that, the 1 PPS from the GPS receiver is actually better
(more accurate). That's why the LO is disciplined by GPS, not the
other way around.
I would also
Hi
Take a look at the PIC-TIC stuff. They have the HP circuit in the middle of it.
Bob Stewart posted a circuit with a pair of tri-state gates in it within the
last month or so.
They all pretty much:
1) Measure the “coarse time” with a counter Today that’s just about always a
counter in an
!
Matt Martin
On Wed, 3/26/14, Bob Camp li...@rtty.us wrote:
Subject: Re: [time-nuts] Hanging bridge question
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Date: Wednesday, March 26, 2014, 4:45 AM
Hi
Take a look
?
Just want to make sure
I am not missing some other meaning.
Thanks, learning a lot from reading this group!
Matt Martin
On Wed, 3/26/14, Bob Camp li...@rtty.us wrote:
Subject: Re: [time-nuts] Hanging bridge question
To: Discussion
Bob,
Thanks. That was too obvious, but having not looked at HP's similar circuits I
ruled it out. Many thanks.
Still lots to learn here…..
Matt
On Wed, 3/26/14, Bob Camp li...@rtty.us wrote:
Subject: Re: [time-nuts] Hanging bridge question
In message CACYeN9zf-UO1sCTCRMHSDPN4u=ye0xb9+x71eLxBnbT=xgw...@mail.gmail.com
, Jim Miller writes:
I've spent a good part of the afternoon looking at all the plots, websites
and the few papers I could find mentioning the hanging bridge. As far as I
can tell as long as one is correcting for
Hi
Exactly correct, the sawtooth corrects for the hanging bridges.
Since that’s what it does, sawtooth correction error is not totally random.
Hanging bridges are not totally random. One looks like the other. Sawtooth
correction errors can / will have hanging bridges in them.
If you are
In message 6b362a4d-834a-4733-bed8-fcfec0ccb...@rtty.us, Bob Camp writes:
I should add here, that you _can_ do a little bit better than the
sawtooth correction.
We know, or at least assume, that the GPS's internal clock is step-less
and slowly changing, so if you put a predictive filter on this
Hi
Most of the more modern receivers don’t stop at one ns resolution on the
correction. You can go well below the ns level with them. If you are doing it
in software, it’s pretty much free.
Bob
On Mar 25, 2014, at 7:27 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message
The lowest cost solution is a DS chip in combination with a PIC. How ever
has any one thought about a fix by going to the source of the problem. The
TCXO. Use a DDS with internal multiplier like the AD9851 or AD 9913 and use
the sawtooth message from the GRS receiver and change the
Thanks for all the helpful replies!
Lots to learn.
73
jim ab3cv
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On Tue, Mar 25, 2014 at 5:44 AM, ewkeh...@aol.com wrote:
The lowest cost solution is a DS chip in combination with a PIC. How ever
The lowest cost solution is to do the correct entirely in software.
After the measure the phase, simply add the correction.
All you need to know is the phase.
Yes if you want to use it only in a GPSDO and it is being done but if you
are a time nut you may want the 1 PPS..
Bert Kehren
In a message dated 3/25/2014 6:33:12 P.M. Eastern Daylight Time,
albertson.ch...@gmail.com writes:
On Tue, Mar 25, 2014 at 5:44 AM, ewkeh...@aol.com wrote:
The
Hi
If you are building a GPSDO, then the 1 pps out of the GPSDO should be much
better than the pps out of the GPS. Making that happen is part of the control
optimization.
Bob
On Mar 25, 2014, at 7:46 PM, ewkeh...@aol.com wrote:
Yes if you want to use it only in a GPSDO and it is being done
The lowest cost solution is to do the correct entirely in software.
After the measure the phase, simply add the correction.
All you need to know is the phase. There is not point in correcting
the pulse, you don't need a corrected pulse. What you want is a
measurement of the phase.
Chris
I'm
Hi
There have been multiple posts about analog TDC’s of various designs that get
you into the sub 100 ps range without costing very much money. I believe the
cheapest posted so far adds 50 cents to a basic PIC based design.
Bob
On Mar 25, 2014, at 7:38 PM, Jim Miller j...@jtmiller.com
Right now I'm planning to use a DS1123 driven by the PIC in my system to
provide sawtooth correction. The phase measurement is strictly binary with
a D FF. The PIC reads the value once a second and integrates with a bit of
feedforward for stability. The numerical result will be fed to a DAC which
Bob
I'm not sure who you're responding to but I have a couple of questions:
TDC = Time Delay Correlator?
Could you point me to one of these 50 cent threads? I've read a ton of this
list from 2007 forward but must have missed that.
Thanks
jim ab3cv (much to learn)
Hi
There have been multiple
If you are building a GPSDO, then the 1 pps out of the GPSDO should be much
better than the pps out of the GPS.
Bob,
That's only true for time scales less than the cross-over point. Beyond that,
the 1 PPS from the GPS receiver is actually better (more accurate). That's why
the LO is
The lowest cost solution is to do the correct entirely in software.
After the measure the phase, simply add the correction.
All you need to know is the phase. There is not point in correcting
the pulse, you don't need a corrected pulse. What you want is a
measurement of the phase.
This
I've spent a good part of the afternoon looking at all the plots, websites
and the few papers I could find mentioning the hanging bridge. As far as I
can tell as long as one is correcting for sawtooth there's nothing
additional to do about hanging bridges.
They merely show up as funny waveforms
j...@jtmiller.com said:
I've spent a good part of the afternoon looking at all the plots, websites
and the few papers I could find mentioning the hanging bridge. As far as I
can tell as long as one is correcting for sawtooth there's nothing
additional to do about hanging bridges.
They
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