How long do you let it run? Does the crystal oscillator oven get warm? If
you let it run more than 15 minutes, and the oven gets hot, the next thing
to check is the output frequency range as the tuning voltage sweeps. Not
having a frequency counter hurts but there are other methods. One is to use
WWV on 10 MHz. You should hear the output slowly sweep through WWV, first on
one side of zero beat and then through zero beat to the other side. If the
beat stays on one side, the VCO needs tweaking to get the sweep somewhat
symmetrical about the 10 MHz WWV signal.

John  WA4WDL

From: "Garren Davis" garren.davis@qlogic.com
Sent: Friday, February 08, 2013 7:12 PM
To: time-nuts@febo.com
Subject: [time-nuts] FRK-L Rubidium

Hi

First thing to check is indeed the frequency of the 10 MHz oscillator. There's a good chance it's simply aged far enough that it will no longer lock up. If the drift isn't super far, the oscillator can be adjusted. The TBolt and a good counter will tell you everything you need to know about the 10 MHz.

If the oscillator is sweeping past the correct frequency, the next thing to check is the output of the SRD assembly. Your scope should be able to "see" that signal. If it's missing, then track it back down the multiplier chain.

Bob

On Feb 8, 2013, at 7:12 PM, Garren Davis garren.davis@qlogic.com wrote:

I've let it run for hours and it gets warm. It has a heat sink and it all gets warm. There are two adjustment screws. One under the heat sink and one on the side of the unit. Is one for the vco and the other for the C-field?

On Feb 8, 2013, at 4:53 PM, "jmfranke" jmfranke@cox.net wrote:

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Hi Garren,

I suggest that you get the Thunderbolt working first.  Without a known
10 MHz source to compare to, you're flying blind.  Once the Tbolt is
running, you should be able to check the frequency of the FRK by feeding
both into your scope.  Trigger on the Tbolt and watch what the FRK
does.  You should see the trace scrolling in one direction, then slow
down, then stop, then scroll the other direction.  The 'stop' point is
at 10 MHz.  The frequency sweeps a total of 20-30 Hz so it's easy to
see.  If you don't see the 'stop' point, the FRK isn't getting to 10
MHz.  Now use the best frequency counter you've got to measure the
Tbolt.  Regardless of the calibration of your counter, the number your
counter gives you becomes your 'new' 10 MHz.  Now measure the FRK to see
if it's running fast or slow.

You should check the temperature of the lamp.  It's easy to get at by
removing the cover in the center of the heat sink.  Probably best to
remove the cover and then power down before you go poking around
inside!  The temperature of the cavity is also important, but getting to
it is more of a hassle - don't go there if you don't have to.

Of course, check for the normal things like internal power supply
voltages, ripple, current drain (both initial and steady-state), etc.

Regarding your second message, yes, the adjustment under the heat sink
near the edge is the C-field.  That won't help you at this point.  The
adjustment in the center of one side is the VCO.  You could try
adjusting it, but like I said, you're flying blind at this point.  You
won't know if you're adjusting closer to 10 MHz or further away.

Good luck,

Ed

On 2/8/2013 6:12 PM, Garren Davis wrote:

Well for some reason the 10 Mhz stopped working on the FRK. Don't know why. Started up the thunderbolt. It acquired satellites but then the DAC voltage went to -5 volts. It's been there for an hour. Will this change after the unit stabilizes? Going to bed. Will check it tomorrow.

Garren

On Feb 8, 2013, at 8:25 PM, "Ed Palmer" ed_palmer@sasktel.net wrote:

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Do you have the service manual? If not, get it here...
http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/Efratom

As I recall there's pretty good trouble shooting in the manual. Several
years ago I fixed an FRK-H that wouldn't lock. The crystal osc had
drifted enough that the trimmer didn't have enough range to tune to the
lock freq. Fix was to pull one small cap that was in parallel with the
trimmer. (C-11 on Osc schematic A21.)

If you have a counter that you trust, it should be easy to see if tuning
is reasonable. The manual will show where the trimmer is. I think I
recall looking at the modulation signal as shown in fig 3-2 in the
manual as I didn't have an accurately calibrated counter at the time. (I
wasn't able to get to a balanced 2fm output signal until I modified the
circuit.)

On 2/8/2013 6:50 PM, Garren Davis wrote:

Hi

DAC clamped at -5 volts suggests that the TBolt has issues. First thing to check is the -12 volt supply. If it's missing, the DAC will indicate -5 on the screen and be sitting at 0 in real life. There are a couple other things in the DAC circuit that can make it malfunction.

Bob

On Feb 9, 2013, at 1:09 AM, Garren Davis garren.davis@qlogic.com wrote:

Hi

How old is the FRK? Does it look like it's been run without a heat sink for very long? They tend to get flaky if run for a while (many months) without heat sinking. There's nothing mysterious about it. The MTBF of the parts gets noticeably worse as the unit heats up.

Bob

On Feb 9, 2013, at 1:09 AM, Garren Davis garren.davis@qlogic.com wrote:

Thanks for the reply.
I found that the 12v current is only 60ma. I suppose that means the Osc. heater is not working. I'm not having much luck with this time nuts stuff. First the FRK and now the thunderbolt. Guess I'll start looking for another one.

Garren

On Feb 9, 2013, at 6:01 AM, "Bob Camp" lists@rtty.us wrote:

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Hi

The +12 V supply at 60 ma likely means that the heater in the OCXO is not working. If you have 60 ma on the -12 V supply, it's pulling about 10X more than it should.

Bob

On Feb 9, 2013, at 10:01 AM, Garren Davis garren.davis@qlogic.com wrote:

Found my problem with the FRK. R31 on the Osc board was burned and open. This was caused by a shorted C16. Replaced and it is now locked. The lock voltage is 12.7v. Is this good or should it be lower?

Garren

On Feb 9, 2013, at 6:10 AM, "Bob Camp" lists@rtty.us wrote:

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Hi

Let it run for a couple of days. If it's still up at  > 11V, I'd tweak it down a bit.

Bob

On Feb 9, 2013, at 12:38 PM, Garren Davis garren.davis@qlogic.com wrote:

Hi Garren,

Congrats on your repair.  Since the crystal control voltage is spec'd as
~1 to 12 Vdc, you're apparently holding onto lock by the narrowest of
margins.  You definitely want to adjust the oscillator to bring that
voltage closer to the middle of it's range.

Ed

On 2/9/2013 11:38 AM, Garren Davis wrote:

Bob,

That was my thoughts also. The GPS receiver and serial connection to the computer are working so I know the power connections are ok. I think I bought this through a group buy from someone on this list and they said all were tested before they were shipped. Maybe it was just time for the heater to fail. Are these trimbles repairable or is it easier to just replace these?

Garren

On Feb 9, 2013, at 8:14 AM, "Bob Camp" lists@rtty.us wrote:

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Hi Ed,

The voltage swings from 2v to 17v. Doesn't that mean I have about 4 to 5 volt margin if it's locked at 12 volts?

I had to adjust the capacitor out almost all the way to get it to lock. If I need to adjust it more can I use the C-field adjustment or should I stay away from that?

Garren

On Feb 9, 2013, at 10:48 PM, "Ed Palmer" ed_palmer@sasktel.net wrote:

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Hi

The OCVCXO  tuning voltage adjust on the 10 MHz simply centers up the sweep process. It has no impact on the output frequency once the unit is locked up.

The C field adjustment sets the Rb on frequency once it is locked. It is only used to set the unit on frequency.

Since the range on the C field is maybe 0.002 ppm and the 10 MHz set is maybe 1 ppm, there is little the C field would do to "help" the 10 MHz adjust.

It is quite possible for the crystal in the 10 MHz oscillator to age further than tuning range on the oscillator. You can either replace the crystal (good luck)  or fiddle one of the fixed caps in the oscillator circuit (normally much easier).

Bob

On Feb 10, 2013, at 10:27 AM, Garren Davis garren.davis@qlogic.com wrote:

Hi Garren,

Yes, you're right.  Silly me, I made the mistake of believing what was
written in the manual which says 2-12 volts. When I measure it, I see
~2-16 volts.  Let that be a warning to you.  This isn't the first time
that manual has led me astray!  I should have known better.

Did you notice that the voltage changes as you adjust the capacitor on
the side?  If the adjustment is at it's limit, you may have to change
capacitors A3C11 and maybe A3C12 to get the oscillator back on
frequency.  It's explained in the manual.  :-)  Let it settle for at
least a few days and see which direction the crystal control voltage
moves.  If it falls you're fine.  If it rises higher, you may want to
look at the capacitors.  If you have to change the capacitors, be sure
to use NP0/C0G type capacitors.

Bob's comments regarding the C-field are right on the money.  It's for
fine tuning after you have a stable lock.  It won't help you obtain or
maintain a lock.  You won't be able to adjust it without a known, stable
10 MHz reference source like the Tbolt and some good measurement equipment.

Ed

On 2/10/2013 9:27 AM, Garren Davis wrote:

Ed, Bob,

This morning I noticed the crystal control voltage was down to 11 volts. I'll let it keep running to
see if it drops any further. The tuning capacitor is adjusted out about as far as I want to set it. Any
further and I think the adjustment screw will fall out. I did remove C11 as an experiment to see what
it would do to the frequency. It dropped a lot so now I know I can put a smaller one in if I need more
adjustment.

Next up is the Tbolt. I'm pretty sure the oven heater is not working. Has anyone taken apart the trimble
oscillator? It looks like it's sealed pretty good. I see quite a few for sale. Is it just easier to
replace it?

Thanks for all the help.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Ed Palmer
Sent: Sunday, February 10, 2013 11:02 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FRK-L Rubidium

Hi Garren,

Yes, you're right.  Silly me, I made the mistake of believing what was written in the manual which says 2-12 volts. When I measure it, I see
~2-16 volts.  Let that be a warning to you.  This isn't the first time that manual has led me astray!  I should have known better.

Did you notice that the voltage changes as you adjust the capacitor on the side?  If the adjustment is at it's limit, you may have to change capacitors A3C11 and maybe A3C12 to get the oscillator back on frequency.  It's explained in the manual.  :-)  Let it settle for at least a few days and see which direction the crystal control voltage moves.  If it falls you're fine.  If it rises higher, you may want to look at the capacitors.  If you have to change the capacitors, be sure to use NP0/C0G type capacitors.

Bob's comments regarding the C-field are right on the money.  It's for fine tuning after you have a stable lock.  It won't help you obtain or maintain a lock.  You won't be able to adjust it without a known, stable
10 MHz reference source like the Tbolt and some good measurement equipment.

Ed

On 2/10/2013 9:27 AM, Garren Davis wrote:

ge and I
'd like to put them to use. Any help would be appreciated.

time-nuts mailing list -- time-nuts@febo.com
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It is possible to open the can if you are careful. A good vacuum desoldering
tool is a good start to remove as much of the solder as possible. Then one
would peal the can open a bit at a time. Then you need to find out where the
failure is.

But to answer your question, yes just buy one, it's much easier. But first
check that there is power to the heater.

----- Original Message -----
From: "Garren Davis" garren.davis@qlogic.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Monday, February 11, 2013 12:01 PM
Subject: Re: [time-nuts] FRK-L Rubidium

Ed, Bob,

This morning I noticed the crystal control voltage was down to 11 volts.
I'll let it keep running to
see if it drops any further. The tuning capacitor is adjusted out about as
far as I want to set it. Any
further and I think the adjustment screw will fall out. I did remove C11 as
an experiment to see what
it would do to the frequency. It dropped a lot so now I know I can put a
smaller one in if I need more
adjustment.

Next up is the Tbolt. I'm pretty sure the oven heater is not working. Has
anyone taken apart the trimble
oscillator? It looks like it's sealed pretty good. I see quite a few for
sale. Is it just easier to
replace it?

Thanks for all the help.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Ed Palmer
Sent: Sunday, February 10, 2013 11:02 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FRK-L Rubidium

Hi Garren,

Yes, you're right.  Silly me, I made the mistake of believing what was
written in the manual which says 2-12 volts. When I measure it, I see
~2-16 volts.  Let that be a warning to you.  This isn't the first time that
manual has led me astray!  I should have known better.

Did you notice that the voltage changes as you adjust the capacitor on the
side?  If the adjustment is at it's limit, you may have to change capacitors
A3C11 and maybe A3C12 to get the oscillator back on frequency.  It's
explained in the manual.  :-)  Let it settle for at least a few days and see
which direction the crystal control voltage moves.  If it falls you're fine.
If it rises higher, you may want to look at the capacitors.  If you have to
change the capacitors, be sure to use NP0/C0G type capacitors.

Bob's comments regarding the C-field are right on the money.  It's for fine
tuning after you have a stable lock.  It won't help you obtain or maintain a
lock.  You won't be able to adjust it without a known, stable
10 MHz reference source like the Tbolt and some good measurement equipment.

Ed

On 2/10/2013 9:27 AM, Garren Davis wrote:

ge and I
'd like to put them to use. Any help would be appreciated.

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you are not the intended recipient, you may not read, copy, distribute, or
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and follow the instructions there.

Bob,

Just wanted to let you know your advice to let the FRK run for a while was spot on.
The lock voltage is down to 9.2 volts.

I was able to get my thunderbolt with the bad oscillator oven working by heating the
oscillator with a power resistor. After it locked I could see on an oscilloscope that
it and the FRK were both exactly the same. I plan on putting the thunderbolt oscillator
in an oven I'm building that will have proportional control and see how that works.

Thanks for the help.
Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Saturday, February 09, 2013 10:14 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FRK-L Rubidium

Hi

Let it run for a couple of days. If it's still up at  > 11V, I'd tweak it down a bit.

Bob

On Feb 9, 2013, at 12:38 PM, Garren Davis garren.davis@qlogic.com wrote:

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Hi

Keep in mind that the top label on the OCXO shows the order number for the part, not it's part number. Anything you find at auction that's labeled "Trimble OCXO" probably will work with the TBolt.

Bob

On Feb 25, 2013, at 6:47 PM, Garren Davis garren.davis@qlogic.com wrote:

Hi

Useful link:

http://www.ke5fx.com/heather/readme.htm

For a screen command list hit space. Poking around at them can be fun!

To get into the OCXO calibration hit d followed by e. Only works after you are locked up.

Bob

On Feb 25, 2013, at 6:45 PM, J. L. Trantham jltran@att.net wrote:

Hi

The unit should not be overly sensitive to temperature. I'd guess that your improvised oven isn't holding temperature very well. The original likely held things to within < 0.1 C at some target in the 85 to 110C range.

Bob

On Feb 25, 2013, at 7:39 PM, Garren Davis garren.davis@qlogic.com wrote:

From the attachment I see he is near LA with a nice house with a kidney shaped pool :-)

Raj

At 26-02-2013, you wrote:

To quote WarrenS:

-Chuck Harris

Garren Davis wrote:

All Trimble OCXOs may work in a Thunderbolt, but not all are drop-in
replacements.
The one I got was much thicker than the original dead part, and the
polarity of the
control signal is inverted.    I got it working but it won't fit in the
original enclosure.

On 02/25/2013 04:12 PM, Bob Camp wrote:

--
Chuck Forsberg WA7KGX  caf@omen.com  www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc      "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231  503-614-0430

Hi

…. the thicker one is a double oven. Well worth the effort.

Bob

On Feb 26, 2013, at 2:58 AM, Chuck Forsberg WA7KGX N2469R caf@omen.com wrote:

I didn't know Google provided such good views of the house. Facing the house you are looking
north. You can see the white GPS antenna behind the satellite dish. It has a pretty good view
of the sky east, south, and west. I probably could get it a little higher. You can probably
tell from all the antennas on the cars and house that I am a Ham (KB6FAS). This time-nuts
thing is just another hobby I don't have enough time to spend on.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Raj
Sent: Monday, February 25, 2013 7:41 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

From the attachment I see he is near LA with a nice house with a kidney shaped pool :-)

Raj

At 26-02-2013, you wrote:

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from the tbolt temperature sensor as the tbolt is in the outer oven. The inner oven where the
oscillator is located holds at 66.4C. My concern is that it looks like the tbolt algorithm controls
the DAC voltage depending on the temperature that the tbolt reads. Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the DAC voltage changing
if the temperature in the outer oven is changing. Is there any way to tell the tbolt algorithm to
ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Monday, February 25, 2013 6:22 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The unit should not be overly sensitive to temperature. I'd guess that your improvised oven isn't holding temperature very well. The original likely held things to within < 0.1 C at some target in the 85 to 110C range.

Bob

On Feb 25, 2013, at 7:39 PM, Garren Davis garren.davis@qlogic.com wrote:

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Bob,

To me it looks like a d followed by an e just enables the DAC control voltage. Am I missing
something? Does it do a calibration of some kind?

Thanks for all your help.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Monday, February 25, 2013 4:24 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Useful link:

http://www.ke5fx.com/heather/readme.htm

For a screen command list hit space. Poking around at them can be fun!

To get into the OCXO calibration hit d followed by e. Only works after you are locked up.

Bob

On Feb 25, 2013, at 6:45 PM, J. L. Trantham jltran@att.net wrote:

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Hi

Sorry about that.

Try & followed by a

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, February 26, 2013 11:32 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Bob,

To me it looks like a d followed by an e just enables the DAC control
voltage. Am I missing
something? Does it do a calibration of some kind?

Thanks for all your help.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Monday, February 25, 2013 4:24 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Useful link:

http://www.ke5fx.com/heather/readme.htm

For a screen command list hit space. Poking around at them can be fun!

To get into the OCXO calibration hit d followed by e. Only works after you
are locked up.

Bob

On Feb 25, 2013, at 6:45 PM, J. L. Trantham jltran@att.net wrote:

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you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
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The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part)
Phase error at -100ns is ~50 times high for the 100 sec TC setting used,
(likely due to the high drift rate of the Osc)
Frequency error is wondering around 1e-10 is about 50 times higher than what
is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what
is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in
general
The Tbolt temperature reading has no direct effect on the Dac control
voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change,
not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok
that I attached a screen dump of what I have. Can anyone comment on the
picture. It's been
running less than a day and I don't know if what I have would be considered
good as far as
accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the
oscillator is located holds at 66.4C. My concern is that it looks like the
tbolt algorithm controls
the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing
if the temperature in the outer oven is changing. Is there any way to tell
the tbolt algorithm to
ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

How does one set the AMU value with LH?

On 2/26/2013 12:05 AM, Chuck Harris wrote:

Hit the f key then the l key.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Peter Gottlieb
Sent: Tuesday, February 26, 2013 4:37 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

How does one set the AMU value with LH?

On 2/26/2013 12:05 AM, Chuck Harris wrote:

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This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to understand why
the PPS trace is doing what it is doing. Looks like it might have something to do with
the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend. I'll do a 24 hour
survey and start another run. After that I'll try a different power supply. Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is ~50 times high for the 100 sec TC setting used, (likely due to the high drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50 times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in general The Tbolt temperature reading has no direct effect on the Dac control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change, not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok
that I attached a screen dump of what I have. Can anyone comment on the
picture. It's been
running less than a day and I don't know if what I have would be considered
good as far as
accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the
oscillator is located holds at 66.4C. My concern is that it looks like the
tbolt algorithm controls
the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing
if the temperature in the outer oven is changing. Is there any way to tell
the tbolt algorithm to
ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly
follows this temperature. The OCXO is likely moving 3 ppb as the temperature
changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the
OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to
understand why
the PPS trace is doing what it is doing. Looks like it might have something
to do with
the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high
drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50
times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what
is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in
general The Tbolt temperature reading has no direct effect on the Dac
control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change,
not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok
that I attached a screen dump of what I have. Can anyone comment on the
picture. It's been
running less than a day and I don't know if what I have would be considered
good as far as
accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the
oscillator is located holds at 66.4C. My concern is that it looks like the
tbolt algorithm controls
the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing
if the temperature in the outer oven is changing. Is there any way to tell
the tbolt algorithm to
ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic
Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

I don't doubt that my oven could be the problem but I would think a lot of people have their tbolts sitting in a room or basement with a lot more temperature swing than 2.5C. I also monitor the inner oven temperature where the oscillator is located and it remains stable at 67C regardless of the 2.5C swing of the outer oven. This makes me wonder if the tbolt temperature is used in the algorithm that steers the osc frequency. I'll have to try some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly follows this temperature. The OCXO is likely moving 3 ppb as the temperature changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to understand why the PPS trace is doing what it is doing. Looks like it might have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50 times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in general The Tbolt temperature reading has no direct effect on the Dac control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change, not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I hope it's ok that I attached a screen dump of what I have. Can anyone comment on the picture. It's been running less than a day and I don't know if what I have would be considered good as far as accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The inner oven where the oscillator is located holds at 66.4C. My concern is that it looks like the tbolt algorithm controls the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the DAC voltage changing if the temperature in the outer oven is changing. Is there any way to tell the tbolt algorithm to ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Hi

The TBolt does not use the temperature monitor when in locked mode. Your
OCXO is changing temperature. Roughly a 0.008 C temperature change would
explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of
people have their tbolts sitting in a room or basement with a lot more
temperature swing than 2.5C. I also monitor the inner oven temperature where
the oscillator is located and it remains stable at 67C regardless of the
2.5C swing of the outer oven. This makes me wonder if the tbolt temperature
is used in the algorithm that steers the osc frequency. I'll have to try
some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly
follows this temperature. The OCXO is likely moving 3 ppb as the temperature
changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the
OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to
understand why the PPS trace is doing what it is doing. Looks like it might
have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high
drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50
times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what
is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in
general The Tbolt temperature reading has no direct effect on the Dac
control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change,
not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok that I attached a screen dump of what I have. Can anyone
comment on the picture. It's been running less than a day and I don't know
if what I have would be considered good as far as accuracy and stability is
concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the oscillator is located holds at 66.4C. My concern is
that it looks like the tbolt algorithm controls the DAC voltage depending on
the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing if the temperature in the outer oven is changing. Is
there any way to tell the tbolt algorithm to ignore the temperature in its
DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic
Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

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you are not the intended recipient, you may not read, copy, distribute, or
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and follow the instructions there.

Garren wrote:

What you see is the GPS discipline doing its job.

As others have said, the temperature reported by the Thunderbolt's
internal sensor is not used by the Tbolt during locked operation (you
can find lots of posts on this subject in the archives).  Note that
your white oscillator trace sits stably on frequency (at time scales
comparable to the temperature changes).  This is because the Tbolt
control loop is counteracting the temperature drift of the crystal.

If the crystal frequency was not varying with temperature but the
Tbolt was running the DAC up and down in response to the internal
temperature sensor (as you posit), you would expect to see the white
oscillator trace tracking the temperature and DAC traces as the
oscillator was erroneously forced off frequency by the control loop.

Best regards,

Charles

Opps, Now your confusing me. You say the tbolt does not use the temperature monitor when in locked mode. In your previous message you said "The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly follows this temperature". Do you mean the inner oven is changing .008C because of the 2.5C change in the outer oven?
I'll back away from all the questions for a while and study this a bit. Probably move some thermistors to different locations.

It is fun trying different things and seeing what happens.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your OCXO is changing temperature. Roughly a 0.008 C temperature change would explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of people have their tbolts sitting in a room or basement with a lot more temperature swing than 2.5C. I also monitor the inner oven temperature where the oscillator is located and it remains stable at 67C regardless of the 2.5C swing of the outer oven. This makes me wonder if the tbolt temperature is used in the algorithm that steers the osc frequency. I'll have to try some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly follows this temperature. The OCXO is likely moving 3 ppb as the temperature changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to understand why the PPS trace is doing what it is doing. Looks like it might have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50 times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in general The Tbolt temperature reading has no direct effect on the Dac control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change, not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I hope it's ok that I attached a screen dump of what I have. Can anyone comment on the picture. It's been running less than a day and I don't know if what I have would be considered good as far as accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The inner oven where the oscillator is located holds at 66.4C. My concern is that it looks like the tbolt algorithm controls the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the DAC voltage changing if the temperature in the outer oven is changing. Is there any way to tell the tbolt algorithm to ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Hi

Your makeshift oven is changing >= 0.008C when the ambient temperature changes 2.5C. The frequency of the OCXO tracks the temperature as reported by the TBolt's sensor. It is NOT being controlled by the TBolt's sensor.

Bob

On Feb 27, 2013, at 5:43 PM, Garren Davis garren.davis@qlogic.com wrote:

I finally got the antenna outside, but just onto a deck railing and not yet up
high on the roof.  Before I do that, does it look like I'm getting decent
performance from it?  Here is the LH display:

Once up on the roof the Westerly exposure will be improved, but North East and
South are pretty much clear right now.

Does anything else look suspicious or wrong?

Any hints greatly appreciated!

On 2/26/2013 1:53 PM, WarrenS wrote:

Hi

If there was a file / image attached , it didn't make it through. North doesn't matter much, South is a very big deal. That of course assumes you are in the US or Europe.

Bob

On Mar 2, 2013, at 9:45 PM, Peter Gottlieb nerd@verizon.net wrote:

Typical, the image didn't go through.  Here is a link to it:
http://petergottlieb.com/images/tbolt.gif

On 3/2/2013 9:45 PM, Peter Gottlieb wrote:

Hi

As much as can be told from a 17 minute plot - looks ok. The antenna could indeed be a bit higher and that would hopefully take care of the crummy sat c/n numbers. What kind of feed line / antenna are you using? Cable TV RG-6 quad shield from your local big box store is a real good choice for the coax. RG-58/59 are not as good at this frequency.

Bob

On Mar 2, 2013, at 9:52 PM, Peter Gottlieb nerd@verizon.net wrote:

The antenna has a pretty clear sky view right now.  I have about 75 feet of
cable, 25 feet that came attached permanently to the antenna, might be RG-59,
and a 50 foot extension which is a new piece of good quality RG-6 CATV cable.

Perhaps the antenna (came with the tbolt in the ebay deal) is not that good and
I should get something better before taking the effort to get it up in its
permanent location?

On 3/2/2013 10:06 PM, Bob Camp wrote:

Peter wrote:

If you are not using a timing-grade antenna, changing it would be a
good idea -- but be prepared for your c/n numbers not to change
dramatically.  If you get a new one, make sure it is a 5 V antenna.

You say that the E and S exposures are pretty much clear, but the
plot shows poor c/n below 30-45 degrees elevation.  You may find that
your ADEV improves if you change the elevation filter to 30 degrees
(it is at 10 degrees now), or change the signal strength filter to
something >= 3.0 AMU (it is at 0.0 now; 3.5-4.0 is often
recommended).  Either of these would reduce the number of satellites
used by the Tbolt at any given time, but getting rid of the noisiest
signals may improve overall performance as long as it does not cause
the Tbolt to go into holdover for lack of satellites.

One of my Tbolts is in a location surrounded by tall trees and I have
an indoor backup antenna in case the external antenna fails.  Using
the backup antenna, its c/n plot looks not too different from
yours.  After much experimentation, I found that the best performance
with the backup antenna is achieved with the elevation filter set to
30 degrees and the signal strength filter set to 3.0 AMU.

Best regards,

Charles

On Sat, Mar 2, 2013 at 7:14 PM, Peter Gottlieb nerd@verizon.net wrote:

YES.  Especially you need to solve the cable problem.  A better
antenna will have a connector so you can have one continuos run of
cable all the same type.  also the timing antenna will mount to a 1"
pipe and you can make the connection inside the pipe.  With a 75 foot
run you need to start thinking more seriously about cable.

No, I don't think your antenna has a very good view of the sky.  the
plot says the overhead view is good but the horizon is blocked.  The
"good view" means that from the antenna's location you can see the
horizon all the way around 360 degrees (except directly North, that
does not matter.)  You need to place the antenna high enough to se
over thatblockage you have to the So.

--

Chris Albertson
Redondo Beach, California

I think I have my temperature problem fixed. I have included a 24 hour graph. Comments welcomed.
I also did a 48 hour survey. I have more things I'm going to change but wanted to do one thing
at a time. I have a new GPS antenna on the roof but it is not connected yet. I also want to try
a different power supply.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your OCXO is changing temperature. Roughly a 0.008 C temperature change would explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of people have their tbolts sitting in a room or basement with a lot more temperature swing than 2.5C. I also monitor the inner oven temperature where the oscillator is located and it remains stable at 67C regardless of the 2.5C swing of the outer oven. This makes me wonder if the tbolt temperature is used in the algorithm that steers the osc frequency. I'll have to try some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly follows this temperature. The OCXO is likely moving 3 ppb as the temperature changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to understand why the PPS trace is doing what it is doing. Looks like it might have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50 times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in general The Tbolt temperature reading has no direct effect on the Dac control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change, not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I hope it's ok that I attached a screen dump of what I have. Can anyone comment on the picture. It's been running less than a day and I don't know if what I have would be considered good as far as accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The inner oven where the oscillator is located holds at 66.4C. My concern is that it looks like the tbolt algorithm controls the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the DAC voltage changing if the temperature in the outer oven is changing. Is there any way to tell the tbolt algorithm to ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

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This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Hi

Your dac voltage is still swinging 20 to 25 mV over the period (4 to 5
divisions at 5,000 uV per division). It tracks the temperature as reported
by the sensor just about 1:1 (yellow and green lines follow each other). It
still looks like your OCXO is moving around quite a bit with temperature.

At 3 Hz/volt (best guess on your OCXO) you are moving 0.06 to 0.075 Hz at 10
MHz. That's about 6 to 7.5 ppb for a reported ~ 1 C change (4 to 5 divisions
at 0.2 C per division). Since the two track well, it's a good bet that at
least 90% of what you are seeing it temperature.

One very easy way to see the impact of the OCXO moving around - the yellow
"Holdover: 136 secs" message. For a properly operating unit the dimensions
should be hours, not ~ 2 minutes.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 11:04 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I think I have my temperature problem fixed. I have included a 24 hour
graph. Comments welcomed.
I also did a 48 hour survey. I have more things I'm going to change but
wanted to do one thing
at a time. I have a new GPS antenna on the roof but it is not connected yet.
I also want to try
a different power supply.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your
OCXO is changing temperature. Roughly a 0.008 C temperature change would
explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of
people have their tbolts sitting in a room or basement with a lot more
temperature swing than 2.5C. I also monitor the inner oven temperature where
the oscillator is located and it remains stable at 67C regardless of the
2.5C swing of the outer oven. This makes me wonder if the tbolt temperature
is used in the algorithm that steers the osc frequency. I'll have to try
some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly
follows this temperature. The OCXO is likely moving 3 ppb as the temperature
changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the
OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to
understand why the PPS trace is doing what it is doing. Looks like it might
have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high
drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50
times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what
is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in
general The Tbolt temperature reading has no direct effect on the Dac
control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change,
not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok that I attached a screen dump of what I have. Can anyone
comment on the picture. It's been running less than a day and I don't know
if what I have would be considered good as far as accuracy and stability is
concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the oscillator is located holds at 66.4C. My concern is
that it looks like the tbolt algorithm controls the DAC voltage depending on
the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing if the temperature in the outer oven is changing. Is
there any way to tell the tbolt algorithm to ignore the temperature in its
DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic
Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

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and follow the instructions there.

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Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic
Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

Thanks Bob,

My first run I had an 80mV and 2.5C swing and after some improvements I have a 23mV and 1C swing. So
I was able to make things better but clearly I have a ways to go.

The 136 second holdover was because I opened the oven to make some changes but didn't reset Lady
Heather for a clean run. That was two days before I did a screen capture so everything should have
stabilized.

Can anyone tell me how to turn off the satellite display on the lower right of the display?

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Tuesday, March 05, 2013 9:01 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Your dac voltage is still swinging 20 to 25 mV over the period (4 to 5 divisions at 5,000 uV per division). It tracks the temperature as reported by the sensor just about 1:1 (yellow and green lines follow each other). It still looks like your OCXO is moving around quite a bit with temperature.

At 3 Hz/volt (best guess on your OCXO) you are moving 0.06 to 0.075 Hz at 10 MHz. That's about 6 to 7.5 ppb for a reported ~ 1 C change (4 to 5 divisions at 0.2 C per division). Since the two track well, it's a good bet that at least 90% of what you are seeing it temperature.

One very easy way to see the impact of the OCXO moving around - the yellow
"Holdover: 136 secs" message. For a properly operating unit the dimensions should be hours, not ~ 2 minutes.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 11:04 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I think I have my temperature problem fixed. I have included a 24 hour graph. Comments welcomed.
I also did a 48 hour survey. I have more things I'm going to change but wanted to do one thing at a time. I have a new GPS antenna on the roof but it is not connected yet.
I also want to try
a different power supply.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your OCXO is changing temperature. Roughly a 0.008 C temperature change would explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of people have their tbolts sitting in a room or basement with a lot more temperature swing than 2.5C. I also monitor the inner oven temperature where the oscillator is located and it remains stable at 67C regardless of the 2.5C swing of the outer oven. This makes me wonder if the tbolt temperature is used in the algorithm that steers the osc frequency. I'll have to try some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly follows this temperature. The OCXO is likely moving 3 ppb as the temperature changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to understand why the PPS trace is doing what it is doing. Looks like it might have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50 times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in general The Tbolt temperature reading has no direct effect on the Dac control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change, not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I hope it's ok that I attached a screen dump of what I have. Can anyone comment on the picture. It's been running less than a day and I don't know if what I have would be considered good as far as accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The inner oven where the oscillator is located holds at 66.4C. My concern is that it looks like the tbolt algorithm controls the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the DAC voltage changing if the temperature in the outer oven is changing. Is there any way to tell the tbolt algorithm to ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Hi

Get a new OCXO

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 4:39 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Thanks Bob,

My first run I had an 80mV and 2.5C swing and after some improvements I have
a 23mV and 1C swing. So
I was able to make things better but clearly I have a ways to go.

The 136 second holdover was because I opened the oven to make some changes
but didn't reset Lady
Heather for a clean run. That was two days before I did a screen capture so
everything should have
stabilized.

Can anyone tell me how to turn off the satellite display on the lower right
of the display?

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Tuesday, March 05, 2013 9:01 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Your dac voltage is still swinging 20 to 25 mV over the period (4 to 5
divisions at 5,000 uV per division). It tracks the temperature as reported
by the sensor just about 1:1 (yellow and green lines follow each other). It
still looks like your OCXO is moving around quite a bit with temperature.

At 3 Hz/volt (best guess on your OCXO) you are moving 0.06 to 0.075 Hz at 10
MHz. That's about 6 to 7.5 ppb for a reported ~ 1 C change (4 to 5 divisions
at 0.2 C per division). Since the two track well, it's a good bet that at
least 90% of what you are seeing it temperature.

One very easy way to see the impact of the OCXO moving around - the yellow
"Holdover: 136 secs" message. For a properly operating unit the dimensions
should be hours, not ~ 2 minutes.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 11:04 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I think I have my temperature problem fixed. I have included a 24 hour
graph. Comments welcomed.
I also did a 48 hour survey. I have more things I'm going to change but
wanted to do one thing at a time. I have a new GPS antenna on the roof but
it is not connected yet.
I also want to try
a different power supply.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your
OCXO is changing temperature. Roughly a 0.008 C temperature change would
explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of
people have their tbolts sitting in a room or basement with a lot more
temperature swing than 2.5C. I also monitor the inner oven temperature where
the oscillator is located and it remains stable at 67C regardless of the
2.5C swing of the outer oven. This makes me wonder if the tbolt temperature
is used in the algorithm that steers the osc frequency. I'll have to try
some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly
follows this temperature. The OCXO is likely moving 3 ppb as the temperature
changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the
OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to
understand why the PPS trace is doing what it is doing. Looks like it might
have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high
drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50
times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what
is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in
general The Tbolt temperature reading has no direct effect on the Dac
control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change,
not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok that I attached a screen dump of what I have. Can anyone
comment on the picture. It's been running less than a day and I don't know
if what I have would be considered good as far as accuracy and stability is
concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the oscillator is located holds at 66.4C. My concern is
that it looks like the tbolt algorithm controls the DAC voltage depending on
the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing if the temperature in the outer oven is changing. Is
there any way to tell the tbolt algorithm to ignore the temperature in its
DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

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Garren wrote:

In the "Graph" menu (type "g"), you have three choices for displaying
the ADEV tables and/or the satellite map: ADEV tables only (type
"a"), Map only (type "m"), or Both (type "b").  You are now in "Both"
mode.  I don't know if typing "a" will go straight to the ADEV tables
only, or if you have to toggle Both off (type "b") first.  But some
combination of these will get you what you want.

Best regards,

Charles

Achim,

Did you change any temperature controller settings from default values?  I am
seeing about a 10:1 correspondence between ambient changes and internal reported
temperature movement.

Peter

On 3/7/2013 12:32 PM, Achim Vollhardt wrote:

Peter,
I did let the internal algorithm make it's optimization (can't remembere
which key sequence it was) once everything has settled. The lab here has
2-3 degC ambient variations over the day, but putting the Thunderbolt in
a box which is ventilated (well.. fan-ed) by the LH temperature
controller in a steered way, the temperature variations are down to
single clicks of the Thunderbolt-internal thermometer reading (which
appear to be 6 mK).

Achim

I am not convinced the temperature control in mine is functional. For example,
the temperature target seems to not do anything at all.  With the box insulated
the internal temperature is around 46 C and nothing changes if I set that number
to 40 or 50 C, it is still around that 46 plus or minus 1 or 2 C as the
environment changes.

What do you mean by having your fan steered by the LH temperature controller?

As for the optimization, I can't find that key combination.  Is there anywhere a
COMPLETE listing of all the key functions for the program?

Peter

On 3/8/2013 2:57 AM, Achim Vollhardt wrote:

Hi Peter,

first of all, LH can only 'control' temperature, if it has a hand to do
so.. meaning it can steer the RTS line of the RS232 to control a small
fan via PWM. Actually, it could also heat (by putting there a heating
element) but I haven't seen anybody doing it yet. If there is no heater,
heating is done by letting Thunderbolt warm up on its own.

So if the measured temperature is above the setpoint, the fan will be
switched on, otherwise not. Of course the controller is a much more
sophisticated PID controller and the output is PWM so it can actually
regulate the fan speed such, that a nice stable temperature can be
achieved. I think you have to search this mailing list for all these
infos, is has been discussed quite some times.

Keystrokes: These have to be found when checking the .cpp files in the
leady heather package. Sorry, it has been a while for me .. I'll leave
that up to you.

Achim

Peter wrote:

Temperature control is a capability within Lady Heather (not the
Tbolt itself) and requires external hardware (e.g., box and fan) to implement.

Best regards,

Charles

Yeah, that sort of hit me after reading through the code.  I enabled the control
lines in my serial to IP adapter and will hook up a fan in the box setup and see
if I can things to be more stable.

On 3/8/2013 6:11 PM, Charles P. Steinmetz wrote:

Bob,

Took your advice and ordered another OCXO. While waiting for it I decided to cut open the
OCXO with a bad heater that came with the thunderbolt. I found the 1 ohm resistor from the
12 volt pin to the heater circuit popped off its solder pads and was laying between the
insulation and the metal enclosure. While unsoldering the circuit board to fix this the
1 ohm resistor in the oscillator circuit popped off its solder pads. For others that have
OCXO's that don't work this is an easy fix. They are large surface mount resistors and easy
to solder. Anyways I put the circuit board back in the metal enclosure but did not seal
it. I put the OCXO back in my double oven and started a run. The enclosed picture is a 72
hour display. Even though the DAC was still increasing it looked like the PPS had stabilized
so I did an auto calibrate. You can see this at marker 1. That was almost two days ago.

Questions:

1. Is it normal to take this long for the PPS to stabilize?
2. Is it normal for the DAC to keep increasing after two days?
3. In general what numbers would be considered good for the PPS and OSC?

Thanks.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Tuesday, March 05, 2013 2:22 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Get a new OCXO

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 4:39 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Thanks Bob,

My first run I had an 80mV and 2.5C swing and after some improvements I have a 23mV and 1C swing. So I was able to make things better but clearly I have a ways to go.

The 136 second holdover was because I opened the oven to make some changes but didn't reset Lady Heather for a clean run. That was two days before I did a screen capture so everything should have stabilized.

Can anyone tell me how to turn off the satellite display on the lower right of the display?

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Tuesday, March 05, 2013 9:01 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Your dac voltage is still swinging 20 to 25 mV over the period (4 to 5 divisions at 5,000 uV per division). It tracks the temperature as reported by the sensor just about 1:1 (yellow and green lines follow each other). It still looks like your OCXO is moving around quite a bit with temperature.

At 3 Hz/volt (best guess on your OCXO) you are moving 0.06 to 0.075 Hz at 10 MHz. That's about 6 to 7.5 ppb for a reported ~ 1 C change (4 to 5 divisions at 0.2 C per division). Since the two track well, it's a good bet that at least 90% of what you are seeing it temperature.

One very easy way to see the impact of the OCXO moving around - the yellow
"Holdover: 136 secs" message. For a properly operating unit the dimensions should be hours, not ~ 2 minutes.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 11:04 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I think I have my temperature problem fixed. I have included a 24 hour graph. Comments welcomed.
I also did a 48 hour survey. I have more things I'm going to change but wanted to do one thing at a time. I have a new GPS antenna on the roof but it is not connected yet.
I also want to try
a different power supply.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your OCXO is changing temperature. Roughly a 0.008 C temperature change would explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of people have their tbolts sitting in a room or basement with a lot more temperature swing than 2.5C. I also monitor the inner oven temperature where the oscillator is located and it remains stable at 67C regardless of the 2.5C swing of the outer oven. This makes me wonder if the tbolt temperature is used in the algorithm that steers the osc frequency. I'll have to try some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly follows this temperature. The OCXO is likely moving 3 ppb as the temperature changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to understand why the PPS trace is doing what it is doing. Looks like it might have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50 times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in general The Tbolt temperature reading has no direct effect on the Dac control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change, not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I hope it's ok that I attached a screen dump of what I have. Can anyone comment on the picture. It's been running less than a day and I don't know if what I have would be considered good as far as accuracy and stability is concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The inner oven where the oscillator is located holds at 66.4C. My concern is that it looks like the tbolt algorithm controls the DAC voltage depending on the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the DAC voltage changing if the temperature in the outer oven is changing. Is there any way to tell the tbolt algorithm to ignore the temperature in its DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

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and follow the instructions there.

This message and any attached documents contain information from QLogic Corporation or its wholly-owned subsidiaries that may be confidential. If you are not the intended recipient, you may not read, copy, distribute, or use this information. If you have received this transmission in error, please notify the sender immediately by reply e-mail and then delete this message.

Hi

That looks a lot better. Your DAC has moved about 40 mV over the time
period. That's not bad, given what you did to it. The ~ 14 ppb shift should
settle out something much lower in a week or two.

Good numbers on the PPS are in the 2 to 3 ns RMS region. The oscillator
numbers are a best estimate / derived value. It's easier to see what's going
on there by looking at the DAC voltage once things settle.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, March 12, 2013 12:56 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Bob,

Took your advice and ordered another OCXO. While waiting for it I decided to
cut open the
OCXO with a bad heater that came with the thunderbolt. I found the 1 ohm
resistor from the
12 volt pin to the heater circuit popped off its solder pads and was laying
between the
insulation and the metal enclosure. While unsoldering the circuit board to
fix this the
1 ohm resistor in the oscillator circuit popped off its solder pads. For
others that have
OCXO's that don't work this is an easy fix. They are large surface mount
resistors and easy
to solder. Anyways I put the circuit board back in the metal enclosure but
did not seal
it. I put the OCXO back in my double oven and started a run. The enclosed
picture is a 72
hour display. Even though the DAC was still increasing it looked like the
PPS had stabilized
so I did an auto calibrate. You can see this at marker 1. That was almost
two days ago.

Questions:

1. Is it normal to take this long for the PPS to stabilize?
2. Is it normal for the DAC to keep increasing after two days?
3. In general what numbers would be considered good for the PPS and OSC?

Thanks.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Tuesday, March 05, 2013 2:22 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Get a new OCXO

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 4:39 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Thanks Bob,

My first run I had an 80mV and 2.5C swing and after some improvements I have
a 23mV and 1C swing. So I was able to make things better but clearly I have
a ways to go.

The 136 second holdover was because I opened the oven to make some changes
but didn't reset Lady Heather for a clean run. That was two days before I
did a screen capture so everything should have stabilized.

Can anyone tell me how to turn off the satellite display on the lower right
of the display?

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Tuesday, March 05, 2013 9:01 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

Your dac voltage is still swinging 20 to 25 mV over the period (4 to 5
divisions at 5,000 uV per division). It tracks the temperature as reported
by the sensor just about 1:1 (yellow and green lines follow each other). It
still looks like your OCXO is moving around quite a bit with temperature.

At 3 Hz/volt (best guess on your OCXO) you are moving 0.06 to 0.075 Hz at 10
MHz. That's about 6 to 7.5 ppb for a reported ~ 1 C change (4 to 5 divisions
at 0.2 C per division). Since the two track well, it's a good bet that at
least 90% of what you are seeing it temperature.

One very easy way to see the impact of the OCXO moving around - the yellow
"Holdover: 136 secs" message. For a properly operating unit the dimensions
should be hours, not ~ 2 minutes.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Tuesday, March 05, 2013 11:04 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I think I have my temperature problem fixed. I have included a 24 hour
graph. Comments welcomed.
I also did a 48 hour survey. I have more things I'm going to change but
wanted to do one thing at a time. I have a new GPS antenna on the roof but
it is not connected yet.
I also want to try
a different power supply.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 12:12 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The TBolt does not use the temperature monitor when in locked mode. Your
OCXO is changing temperature. Roughly a 0.008 C temperature change would
explain the movement you see.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 1:20 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

I don't doubt that my oven could be the problem but I would think a lot of
people have their tbolts sitting in a room or basement with a lot more
temperature swing than 2.5C. I also monitor the inner oven temperature where
the oscillator is located and it remains stable at 67C regardless of the
2.5C swing of the outer oven. This makes me wonder if the tbolt temperature
is used in the algorithm that steers the osc frequency. I'll have to try
some experiments to see if I can figure this out.

Thanks for the feedback Bob.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bob Camp
Sent: Wednesday, February 27, 2013 9:49 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lady Heather numbers

Hi

The temperature of your TBolt is moving 2.5 C. The OCXO frequency directly
follows this temperature. The OCXO is likely moving 3 ppb as the temperature
changes by 2.5C. That drives the PPS back and forth.

Put another way - most of what you see is related to the problem with the
OCXO and it's lack of a proper oven.

Bob

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Garren Davis
Sent: Wednesday, February 27, 2013 10:27 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Warren,

Thanks for the comments. I've included a 34 hour screen dump. Trying to
understand why the PPS trace is doing what it is doing. Looks like it might
have something to do with the temperature.

I'm going to try a different GPS antenna and mount it higher this weekend.
I'll do a 24 hour
survey and start another run. After that I'll try a different power supply.
Right now I'm
using a PC power supply. It's probably a bit noisy.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of WarrenS
Sent: Tuesday, February 26, 2013 10:53 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

The screen dump is way too short to give much detail.
What can be said from what is there:

It is using the default setting (for the most part) Phase error at -100ns is
~50 times high for the 100 sec TC setting used, (likely due to the high
drift rate of the Osc) Frequency error is wondering around 1e-10 is about 50
times higher than what is possible.
Effect on freq and phase noise with sat changes is >>10 times more that what
is possible with good setup.

Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
Can't say or sure, because the 24 Hr + screen shot is not shown, but in
general The Tbolt temperature reading has no direct effect on the Dac
control voltage unless the Tbolt is in hold over.
The Dac voltage changes because the oscillator's freq is trying to change,
not the other way around.
You can disable the Dac from changing with "dd".

ws

From: "Garren Davis"
Subject: [time-nuts] Lady Heather numbers

Hi,

I have been playing with my thunderbolt and Lady Heather over the weekend. I
hope it's ok that I attached a screen dump of what I have. Can anyone
comment on the picture. It's been running less than a day and I don't know
if what I have would be considered good as far as accuracy and stability is
concerned.
Thanks.
Garren

Garren Davis garren.davis at qlogic.com

from the tbolt temperature sensor as the tbolt is in the outer oven. The
inner oven where the oscillator is located holds at 66.4C. My concern is
that it looks like the tbolt algorithm controls the DAC voltage depending on
the temperature that the tbolt reads.
Temperature goes up, the DAC
voltage goes up. If the inner oven is holding steady then I don't want the
DAC voltage changing if the temperature in the outer oven is changing. Is
there any way to tell the tbolt algorithm to ignore the temperature in its
DAC calculation?

Wow, I hope this makes sense the way I explained it.

Garren

888888888888888888888

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic
Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

This message and any attached documents contain information from QLogic
Corporation or its wholly-owned subsidiaries that may be confidential. If
you are not the intended recipient, you may not read, copy, distribute, or
use this information. If you have received this transmission in error,
please notify the sender immediately by reply e-mail and then delete this
message.

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Do you think that the oven is working correctly? Is the DC current high
on power-up then dropping to a steady lower value after warm-up time?

My concern is that the resistors may have unsoldered themselves because
the oven ran away into an over-temp condition.

On 3/12/2013 9:55 AM, Garren Davis wrote:

Rex,

I checked the current on the oven. It seems to be operating correctly. My theory is
that it worked before it was shipped. This was from the TAPR group buy. They were all
tested before shipping. The resistor probably popped of during shipping. The other
resistor popped off probably from me unsoldering the board from its standoffs and
flexing it in the process. Maybe it was a bad solder job at the factory.

Thanks for the comments.

Garren

-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Rex
Sent: Tuesday, March 12, 2013 4:35 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lady Heather numbers

Do you think that the oven is working correctly? Is the DC current high on power-up then dropping to a steady lower value after warm-up time?

My concern is that the resistors may have unsoldered themselves because the oven ran away into an over-temp condition.

On 3/12/2013 9:55 AM, Garren Davis wrote:

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Hi

If the oven runs away, you won't get the nice "DAC voltage settling to a reasonable value" trace on LH. If it has run away, the appearance is very distinctive when you open it up. Boards turned brown and highly oxidized solder ….

Bob

On Mar 12, 2013, at 7:35 PM, Rex rexa@sonic.net wrote: