[time-nuts] 10 mhz accuracy for a satellite system

Thu Feb 7 19:33:42 UTC 2019

Hi

The white-ish label may just be a variation on the more normal tan-ish looking one.
There’s no reason to avoid a unit just because somebody decided to use a different 
label.

Bob

> On Feb 7, 2019, at 11:19 AM, Richard Solomon <w1ksz at outlook.com> wrote:
> 
> I noticed that a similar Trimble Thunderbolt is for sale over on
> Ali Express. Has older firmware (Ver. 2.2) and a much higher price.
> 
> 73, Dick, W1KSZ
> 
> Sent from Outlook<http://aka.ms/weboutlook>
> ________________________________
> From: time-nuts <time-nuts-bounces at lists.febo.com> on behalf of Bob kb8tq <kb8tq at n1k.org>
> Sent: Tuesday, February 5, 2019 6:17 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system
> 
> Hi
> 
> That’s an odd one. It is very unclear *where* that OCXO came from.
> 
> Bob
> 
>> On Feb 5, 2019, at 7:16 PM, Richard Solomon <w1ksz at outlook.com> wrote:
>> 
>> Here's a shot of what's inside those T-Bolts I bought.
>> (thanks to tvb for reducing the size of my original).
>> 
>> Comments solicited ...
>> 
>> 73, Dick, W1KSZ
>> 
>> Sent from Outlook<http://aka.ms/weboutlook>
>> ________________________________
>> From: time-nuts <time-nuts-bounces at lists.febo.com> on behalf of Bob kb8tq <kb8tq at n1k.org>
>> Sent: Tuesday, February 5, 2019 12:11 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system
>> 
>> Hi
>> 
>> If the sticker on the OCXO (not the label on the outside of the box) has a date code
>> in 2006, that should be fine. I’ve seen cases on … errr … various sites … errr …
>> where the stuff inside the box did not match up very well with the labels on the outside
>> of the box. No idea why ….
>> 
>> Bob
>> 
>>> On Feb 5, 2019, at 12:26 PM, Richard Solomon <w1ksz at outlook.com> wrote:
>>> 
>>> The two I have are Trimbles with Red & Black Labels with White letters.
>>> It's marked D/C 0635, which if I assume is the Date Code puts them in
>>> 2006.
>>> 
>>> 73, Dick, W1KSZ
>>> 
>>> Sent from Outlook<http://aka.ms/weboutlook>
>>> ________________________________
>>> From: time-nuts <time-nuts-bounces at lists.febo.com> on behalf of Bob kb8tq <kb8tq at n1k.org>
>>> Sent: Tuesday, February 5, 2019 8:32 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system
>>> 
>>> Hi
>>> 
>>> The parts we typically call TBolt’s  were produced from about 1997 through about 2006.
>>> The date codes on the parts are one way to work out how far along the uint you have is
>>> in that sequence. There are other parts that Trimble produced (produces) under the same
>>> Thunderbolt brand. Those can be quite different beasts depending on which one you
>>> happen to be looking at.
>>> 
>>> The early parts had OCXO’s labeled “PIEZO” on them. The later parts had a generic
>>> “TRIMBLE” label on them. The PIEZO labels have a date code stamped on them sort
>>> of randomly. The TRIMBLE labels have a field marked “date code”. In all cases I have seen
>>> it’s a two digit year followed by a two digit week.
>>> 
>>> Anything with a PIEZO label is “early”. Anything from about 2003 on should be a pretty good
>>> OCXO.  There are no guarantees, but that’s a pretty good guess.
>>> 
>>> There are also changes in the temperature sensor IC and mods to the firmware along the
>>> way. The novel approach to a precision DAC and the resulting “noticeable” temperature
>>> coefficient seems to have been a constant through the entire production run. They also
>>> have various little spurs and noise bumps that some people get into cleaning up.
>>> 
>>> The good news is that they all (from the first unit to the very last) run very well with LH.
>>> *That* more than any other factor makes them a really good choice. When tuned up,
>>> set up, and monitored with LH, they do much better than they would just running on their own.
>>> 
>>> Bob
>>> 
>>>> On Feb 5, 2019, at 9:23 AM, Richard Solomon <w1ksz at outlook.com> wrote:
>>>> 
>>>> How does one tell the difference between "early" and "later" ?
>>>> 
>>>> S/N, Rev # ??
>>>> 
>>>> 73, Dick, W1KSZ
>>>> 
>>>> Sent from Outlook<http://aka.ms/weboutlook>
>>>> ________________________________
>>>> From: time-nuts <time-nuts-bounces at lists.febo.com> on behalf of Bob kb8tq <kb8tq at n1k.org>
>>>> Sent: Monday, February 4, 2019 7:23 PM
>>>> To: Discussion of precise time and frequency measurement
>>>> Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system
>>>> 
>>>> Hi
>>>> 
>>>> One thing to watch on the TBolts - the ocxo’s used in them got better as the
>>>> years went by. An early one likely will not do quite as well as a later one. They
>>>> also updated the firmware as time went by, same basic issue - later is probably
>>>> better ….
>>>> 
>>>> Bob
>>>> 
>>>>> On Feb 4, 2019, at 8:51 PM, Richard Solomon <w1ksz at outlook.com> wrote:
>>>>> 
>>>>> There have been some Trimble Thunderbolts over on that auction site
>>>>> that were being sold for $80 each (not surplus Telcom ones).
>>>>> I grabbed two and they work.
>>>>> 
>>>>> My antenna was a "hockey puck" style antenna sitting on the window
>>>>> sash, facing South.
>>>>> 
>>>>> 73, Dick, W1KSZ
>>>>> 
>>>>> Sent from Outlook<http://aka.ms/weboutlook>
>>>>> ________________________________
>>>>> From: time-nuts <time-nuts-bounces at lists.febo.com> on behalf of Grant Hodgson <grant at ghengineering.co.uk>
>>>>> Sent: Monday, February 4, 2019 11:15 AM
>>>>> To: time-nuts at lists.febo.com
>>>>> Subject: Re: [time-nuts] 10 mhz accuracy for a satellite system
>>>>> 
>>>>> Paul
>>>>> 
>>>>> The keyword is GPSDO - GPS disciplined oscillator.  The vast majority of
>>>>> these will give a 10MHz output.  The long term accuracy is the same as
>>>>> the GPS navigation system, which for most purposes is similar to that of
>>>>> national standards.  GPSDOs are more stable than most rubidium standards
>>>>> in the long term, and GPSDOs are extremely common in most laboratories.
>>>>> 
>>>>> The Trimble Thunderbolt is very common and available on the surplus
>>>>> market, as is the HP Z3801A.  James Miller (G3RUH) used to sell an
>>>>> excellent GPSDO.  There are other home-brew designs available if you
>>>>> want to build.   These have all been extensively characterised if you
>>>>> want the details.
>>>>> 
>>>>> If you want to buy new, then there are products such as the Fury and
>>>>> Firefly from Jackson Labs; , U-Blox have many offerings (not sure if
>>>>> they do a GPSDO though).
>>>>> 
>>>>> Google GPSDO or GPS frequency standard, or check the leapsecond.com
>>>>> website for more information - there's loads out there, it's just a case
>>>>> of using the right term in the search engine.
>>>>> 
>>>>> regards
>>>>> Grant
>>>>> 
>>>>>> Date: Sun, 3 Feb 2019 23:43:10 -0000
>>>>>> From: "Paul Bicknell" <paul at bicknells.f2s.com>
>>>>>> To: "'Discussion of precise time and frequency measurement'"
>>>>>>   <time-nuts at lists.febo.com>
>>>>>> Subject: [time-nuts] 10 mhz accuracy for a satellite system
>>>>>> Message-ID: <D1F28D64EDD440EC834753538090F381 at precision380>
>>>>>> Content-Type: text/plain;     charset="iso-8859-1"
>>>>>> 
>>>>>> 
>>>>>> Dear all
>>>>>> I currently use a 198 Khz off air standard but I can no longer use  600 khz
>>>>>> since it moved from Rugby
>>>>>> I have herd a lot about varies frequency references that use satellites
>>>>>> This technology has improved immensely & become more affordable over the
>>>>>> past 5 years
>>>>>> 
>>>>>> So can a standard locked to a satellite be as good as a Rubidium ?
>>>>>> 
>>>>>> What accuracy can I achieve for a satellite system below ?800 as I am not
>>>>>> familiar with the latest that are on offer?
>>>>>> 
>>>>>> Regards Paul Bicknell  South Coast UK
>>>>>> 
>>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>> 
>>>> 
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>> 
>>> 
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>> 
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>> <IMG_0987-1200x800.jpg>_______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.