through it to Lady Heather etc,
and capture the temperature, using it appropriately. Should work nicely
and keeps the temp control local. Even put a little LED on it to indicate
state.
Don
WarrenS
TBolt Nuts
To keep My TBolt's temperature constant so that the environment has
minimal effect
This can also be made to work on the TBolt units that have the 1/2 deg course
Temp sensor.
The control loop gets a bit trickier, but it can hold the Temp very close at
one its course transitions points.
This would come in handy for those not wanting to change their sensor to the
high
the
air temperature you will control the entire case of the TBOLT. This will have
much
faster response and may control the case of the OCXO, voltage regulators and
not
just the temperature sensors.
There, I have had my 2c worth,
cheers, Neville Michie
On 27/08/2009, at 5:56 AM, WarrenS
Jim
Silly question, You must not live in California.
Of course it is 1/640 of a square mile
or was it 1/460 of a square something else?
In any case, everyone in California knows it is 1/50,000 of what an average
wild fire burns.
ws
*
- Original Message -
From: Jim Palfreyman
Antonio I8IOV
see wenzel link for nice clear write-up of one way to do it.
http://www.wenzel.com/documents/measuringphasenoise.htm
Because most Freq test show differences, The one thing you need is a good
reference to compare to.
To get numbers without the detailed freq information of the phase
When possible, the thing I do to eliminate the effect of small gravitational
changes or tilt
from effecting the Freq of my Oscillators, is to orientate their case so that
the osc is approximately at its MAXIMUM 2G turn over axes.
This gives the osc a null to small gravitational changes, much
Keep in mind that the batteries are not the only thing on small cheap Domestic
UPS's that are rated for minutes. Same goes with their electronics, Heatsink
etc.
You would have to seriously derate them for continuous duty, and even then it
may not be save.
And in some cases the equipment
?
warren
***
- Original Message -
From: Jim Palfreyman jim77...@gmail.com
To: WarrenS warrensjmail-...@yahoo.com; Discussion of precise time and
frequency measurement time-nuts@febo.com
Sent: Thursday, August 06, 2009 3:24 PM
Subject: Re: [time-nuts] HP 106B quartz frequency
have a real
goal in mind, best to leave it alone.
If it is not broken , DON'T break it.
warren
***
- Original Message -
From: Bob Camp li...@cq.nu
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: WarrenS warrensjmail-...@yahoo.com
Sent
Ulrich
Thanks, I stand corrected, Your point was right on.
My point was; Just maybe John did not really want all the Allan stuff, I could
not tell.
AND true, sorry I did miss YOUR point.
It would seem that you where the ONLY one of us that was NOT confused by the
words.
warren
off all together
And on
time-nuts Digest, Vol 61, Issue 17
all was there, Text and Attachment
Can anyone explain to me what's going on and how these Archives decide what to
delete and ignore?
Thanks,
warren
*
- Original Message -
From: WarrenS warrensjmail
John
If you want quick answers to Frequency differences,
You should think and measure Phase change differences Not Freq differences.
Example: 1e-12 freq offset causes a 1ns shift every 1000 seconds,
NO matter what the Frequencies are that you are comparing.
Any decent standard analog scope can
Ulrich
You are of course correct about Accuracy and Stability, BUT I think it is you
that is confused.
I may be wrong here but it would seem to me that ALL John really cares to
know for now, like most NON-Nuts, is what the freq (difference) is of several
of his good oscillators.
This is all
I just received my TARP Tbolt and it has the 1 deg Temp steps. From the few
test I've done so far, Looks like the neg effect is going to be quite
noticeable at lab conditions where the temp changes only a couple degrees. Any
plans on making a replacement chip available? I also have rev 3
Mark
What this looks like is:
First the phase Jumps, (Makes sense if you move the antenna or it is not where
it thinks it is), This causes the Dac to jump to start correcting for the Phase
error, AND that causes the OSC freq to change which is what causes the Freq
measurement difference.
My
Does anyone know how accurate Google map is for Lat Lon in California?
I can see my GPS antenna measure it's position to within about 1 ft on their
Map.
Any reason to believe that is more accurate than the Tbolt survey, which shows
a 1 Ft by 3 Ft difference?
Can anyone tell me how I can get
What I have found to be helpful is first,
narrow down the problem to the PC OR the Tbolt,
Disconnect the Tbolt,
Run any of the Tbold monitor programs
In whatever operating system you have
Open the View Raw data screen
Enable both the show received and transmit data
Connect Pin 2 to pin3 at the
levels in the oscillator indicate a current
more like 4mA in the 510 ohm resistor.
Bruce
WarrenS wrote:
I just saw your schematic of the rest of the buffer circuit. Sorry I missed
it early.
The Osc Vcc is shown driven from a 510 Ohm resistor, and with the total
current thru the 510 res
oscillator Vcc is then closer to 2.5V.
Earlier circuit schematics didn't include as many actual measured dc
voltages.
Bruce
WarrenS wrote:
Bruce
4ma? Interesting, Maybe IF the Osc was running, BUT
My DC calculations of the present values I can read on Schematics come to
1.3ma + 0.26
to end, that would account for the other
strange voltage readings.
Also if the Freq as small as it is, is still correct, that would eliminate
most of the bad xtral possibilities.
ws
*
- Original Message -
From: WarrenS warrensjmail-...@yahoo.com
To: Discussion
Here is my two cents worth
20 mv output, sure sounds like something is broken.
It should be fixed before it is modified.
The 2.49 volts on the Red input voltage seem LOW, More Vcc maybe.
The Grn labeled wire, FreqCtrl input should be about 1/2 VCC for testing.
If you do 'need' to modify the
*
- Original Message -
From: Bruce Griffiths bruce.griffi...@xtra.co.nz
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, July 03, 2009 8:21 PM
Subject: Re: [time-nuts] Broken Ovenaire OSC 85-50
WarrenS wrote:
Here is my two cents
.
Bruce
WarrenS wrote:
Here is my two cents worth
20 mv output, sure sounds like something is broken.
It should be fixed before it is modified.
The 2.49 volts on the Red input voltage seem LOW, More Vcc maybe.
The Grn labeled wire, FreqCtrl input should be about 1/2 VCC for
testing
...@xtra.co.nz
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, July 03, 2009 9:55 PM
Subject: Re: [time-nuts] Broken Ovenaire OSC 85-50
WarrenS wrote:
A couple more thoughts;
Is the VCC (Red wire) current draw correct?.
Should be 1.3 ma (per the schematic values
that there are limitations in any of the above and many ways
that it can be done wrong, But it can provide a Simple usable test, and in some
cases near state of the art testing, for the beginning time-nut that has not
yet collected all the great test equipment that is so often referred to.
WarrenS
the gain of the EFC
input, the filtered EFC voltage can be use as freq drift information to find
the ADEV's.
WarrenS
*:
What would it take as a minimum for ordinary time-nuts to be able
to perform an ADEV test on their ocxo's and gpsdo's for phase stability at
home,
Warren
solution also.
WarrenS
*
Warren
Another limitation of such phase detectors is that the 2 frequencies
being compared have to be within a small fraction of 1Hz of one another.
This rules out using a low noise reference that happens to have
drifted/aged out of the adjustment range
on to in the
first place?
WarrenS
***
- Original Message -
From: Steve Rooke sar10...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Tuesday, December 30, 2008 8:31 PM
Subject: Re: [time-nuts] Count up/down DAC circuit
Hi Said,
Yes, I
of the Hardware simulator is for someone that wants to know how
accurate their GPSDO is but does not have access to a source accurate enough
to test their GPSDO.
WarrenS
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of the Hardware simulator is for someone that wants to know
how
accurate their GPSDO is but does not have access to a source accurate enough
to test their GPSDO.
WarrenS
Read a paper like this to appreciate the complexities involved:
http://tycho.usno.navy.mil/ptti/ptti2002/paper29.pdf
, on the other hand, does not depend on gravity,
and does not need to be calibrated for location,
AND it can not be use to measure the change in Gravity due to tides etc..
WarrenS
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build units I've heard being used can be 100 to 1000 or
more
times worse than desired for best performance.
WarrenS
That is correct. Because time can be measured more precisely
than any other physical quantities it is quite normal for amateur
projects or even professional products to span many
the antenna to the 1PPS?
It would seem that this may be feasible when used with a receiver that can
output its 1PPS when locked to a single satellite? ? ?
WarrenS
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but related question is, does or would using some form of waas
help a GPSDO?
Have fun with it,
WarrenS
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and follow
to process the phase error data
before
being applied to the DAC. I am not looking for anything secrete or with all the
extra
things some use to verify that the data is valid or appropriate before being
applied
or thrown away.
Thanks, for any information you can provide me.
WarrenS
that I saw was that they just
set their simple filter to about 20 hrs.
WarrenS
**
- Original Message -
From: Ulrich Bangert [EMAIL PROTECTED]
To: 'Discussion of precise time and frequency measurement'
time-nuts@febo.com
Sent: Saturday, December 06, 2008 9:06 AM
Subject: Re: [time
Q) Can you explain again why you are thinking this?
A) Yes, Short answer is I do not think Tom's graph's have finished analyzing
the data.
As soon as I can get a copy of the raw data so that I can check out my claims
in a simulator, I'll show you why I say that.
WarrenS
, if the phase
detectors errors where eliminated.
Have Fun, You sure do nice work and make nice plots.
WarrenS
***
- Original Message -
From: Tom Van Baak [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday
can reduce phase
detector errors
by many orders of magnitude.
WarrenS
*
Bruce Griffiths bruce.griffiths at xtra.co.nz
Fri Dec 5 05:09:53 UTC 2008
a.. Previous message: [time-nuts] Sub Pico Second Phase logger
b.. Messages sorted by: [ date ] [ thread ] [ subject
In message 02c801c956c9$4aa089a0$6401a8c0 at WSOffice, WarrenS writes:
The short of it is that every once in a while the 100 Hz syncs up
for a short time to the 1 Hz
As far as I have ever been able to tell, that is not how it
works.
The 100Hz and 1Hz are generated with the same hardware
please let me know.
WarrenS
Warren
Another potential issue is crosstalk between flipflops in the same
package, in particular between the 2 clock signals.
Such effects will not be evident when using a single clock source to
evaluate the system noise.
Using fully
pointer painting from the side.
You know it sounds like you should look up the optic-nuts.
Or to get more relevant and serious answers you probable need to supply more
information about the requirements.
Having too much Fun
WarrenS
**
- Original Message -
From: Björn
, WarrenS warrensjmail-one at yahoo.com wrote:
To Björn
wow, neat, mm accurate antennas,
That means the RF way still has some hope.
How does it get the information down the cable without unacceptable loss of
accuracy?
Anyone know how they make these antennas, and can it be done with small
, and with the DVM updating at several times a second,
it made fine freq adjustments much easer than slower monitoring ways.
If you know of other simple high resolution phase detectors,
or see any problems or improvements
with the idea, I'd like to hear from you.
Have fun
WarrenS
to offset by up to 0.3051 mV (minus the value of one of the
added bits)
One way to turn a Really good 18 bit Dac into 24 + bits, is scale a 6 bit Dac
thru a resistor to some place on the 18 bit dac that will add 0 to 18.78 uV
+ - 1/2% of offset onto the 18 bit Dac's output.
Have Fun
WarrenS
it needing a have few extra manual
adjustments
in order to get better performance.
WarrenS
*
- Original Message -
From: Bruce Griffiths [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Monday, December 01, 2008 3:38 AM
when tracking at 1000 Sec?
WarrenS
**
WarrenS wrote:
Concerning the Need for very high resolution Dacs in GPSDO.
Bruce said: However there are low noise OCXOs with EFC adjustment
ranges of 1E-6 or more, (that would benefit from 20 bit Dacs)
From what I have seen
know of a posted plot that shows the noise you get using the Carrier
phase techniques?
Do please understand that my questions about using pots etc,
are to get a better understand about what is going on,
Not suggestions on how to make one.
Thanks,
WarrenS
WarrenS wrote
tracking when using a 1E-7 turning range OSC,
and around 18 bits for the same Osc when tracking at 1000 Sec?
WarrenS
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and follow
other than buying some of this parts.
I must add that he was very helpful in my past quest for a good stable voltage
source.
WarrenS
**
Re [time-nuts] time-nuts Geller 10 volt ref. modification.
Hello WarrenS,
Is it possible to have some details of your 1 transistor 1st order
temperature
.
WarrenS
*
RE Brooke Clarke and Warren SO posts:
Message: 6
Date: Sat, 29 Nov 2008 08:24:43 -0800
From: Brooke Clarke brooke at pacific.net
Subject: Re: [time-nuts] Voltage Standards
Hi:
Geller's patent 7382179 Voltage reference with enhanced stability
explains how
he
then
and there.
So to answer your second question, the only things that really requires high
accuracy in
voltage measurements are all the things that are used to calibrate accurate
voltmeters.
Everything else is it would seem is actually done with precisions voltage
ratios.
WarrenS
guys It sure beats the $500
I heard Fluke charges to do their underlying Fluke 732B calibration.
WarrenS
*
RE Message 8 and a couple of earlier posts on standards
Date: Sat, 29 Nov 2008 10:38:53 +1300
From: Bruce Griffiths bruce.griffiths at xtra.co.nz
Subject: Re: [time
Ernie
Concerning the James Miller, Simple GPS Stabilized 10 MHz Oscillator
using 10KHz from the Jupiter-T GPS, schematic posted at
http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm
Although the circuit is definitely made very simple by using the 10KHz.
I feel it has gone just a bit
responses in the text below)
Re: [time-nuts] GPSDO using 100Hz
from Tom Van Baak
Mon, 24 Nov 2008 17:17:34 -0800
by WarrenS
Besides asking if anyone is using the 100Hz output,
I would like to know why it is that the generally available
GPSDO don't use the 100Hz. I have found that this can
...
Also if you would, I'd like to have a better understand of
what seems like an over obsessions with Low Noise GPSDO.
I do understand the need (or at least the desire)
to have low noise oscillators when using them directly for high
frequency and/or short time scale data taking
Bruce Griffiths answered:
Its difficult to make much useful comment as you provide few measured
results.
With an M12+T or equivalent the ADEV of the PPS output (without sawtooth
correction) goes below 1E-10 at Tau 200 sec or so.
Thus with an optimized GPSDO it wont take an hour or so to
Ulrich Bangert
Thanks for the great Information.
UR) James Miller, G3RUH, also uses the 100 Hz signal
Thanks, that is what I was asking for, other people that were using the 100Hz.
Now if I could just figure out how to post a response under an existing
thread, and not have it start a new one
the same circuit and with your testing method chk both
unit...with the same OCXO
the jupiter eng board is still available in the German Ebay
Rgds Ernie.
-Original Message-
From: WarrenS Email [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement
Mike
Neither do I, know how to reply to a post that is. This may be the blind
leading the blind
and end up in some unknown place.
True it would be simpler to use the High freq Osc directly but it would not be
accurate.
The problem with just using the High freq as you suggested is that it is
Sorry my example should of said skip 126 cycles every 500 seconds (500/4 +1)
- Original Message -
From: WarrenS [EMAIL PROTECTED]
To: time-nuts@febo.com
Sent: Monday, November 24, 2008 10:27 AM
Subject: Re: [time-nuts] GPSDO using 100Hz
Mike
Neither do I, know how to reply to a post
WarrenS Email wrote:
Bruce, Thanks for the feedback, Good information to know,
but you seemed to missed my point and question.
in it and must use a processor?
Also I should comment that on LeapSecond.com
http://www.leapsecond.com/pages/gpsdo/
you stated where the ADEV for various GPSDO
Mike
Neither do I, know how to reply to a post that is. This may be the
blind leading the blind and end up in some unknown place.
True it would be simpler to use the High freq Osc directly but it
would not be accurate.
The problem with just using the High freq as you suggested
Warren
The optimum loop time constant depends on the quality of the local
oscillator and the GPS timing receiver timing signals.
A time constant of several hours is only useful with a very high quality OCXO.
The 100Hz output of an M12+T is phase jerked into alignment with the the
second once
Bruce
My Oncore's phase is definitely different on each 100Hz cycle. A digital
storage scope shows it very well.
Some things that come to mine:
1) Not all Oncores are the same, mine is an old 8 channel one. (Don't remember
the number, it is the one with the sawtooth capability)
2) The actual
Warren Answers and comments to /tvb below in the text.
Besides asking if anyone is using the 100Hz output, I would like to ask
why don't the generally available GPSDO use the 100Hz, which can give
about 1 ns of certainly with a simple PLL and analog RC filter, instead of
the using the 1
Tom Van Baak wrote:
This raises some questions on the interpreatation of the M12+T and
Jupiter-T receiver specs.
Some measurements are required in order to settle the questions once and
for all.
Can anyone that has either or both of these receivers make the required
measurements?
This is my first listing so don't know if I'm doing correctly.
Question is: Has anyone done any work using the 100Hz GPS output, instead of
the 1 Hz output?
The reason I ask is because I am in the process of cleaning up my SIMPLE GPS
Freq Phase lock tracker breadboard that does about the same
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