[time-nuts] Redundant GPSDO configuration / hardware

[skipp Isaham via time-nuts]

Redundant GPSDO configuration / hardware  

Hello to the Group, 

I realize integrated redundant GPSDO systems are available. If I wanted to 
obtain a near zero failure down time using (dual) separate GPSDO hardware, is 
there a conventional or practical method to integrate or construct a hot 
standby 
system from hardware not originally part of an integrated package/system? An 
example might be the use of different brand or model GPSDO hardware. 

If a popular method is used to integrate two separate GPSDO outputs in to 
a practical hot standby system, I would appreciate reading your suggestions 
and information. Even comments about obtaining GPSDO output for a control 
system that simply can not fail while in regular service/operation. 

Thank you in advance for your replies. 


Regards, 

Skipp 

skipp025 at yahoo dot com 

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Re: [time-nuts] Rohde & Schwarz GPSDO

[Rami Vainio]

On 7.10.2015 14:45, Arthur Dent wrote:

I believe that like a lot of the Meinberg receivers that
this uses a down converter to give an IF frequency of
35.4 MHz. If you don't have the converter that apparently
isn't included with the receiver you have a $300 paperweight.
You might want to check with the seller before bidding.


Hi, here is quick and dirty way to make your own LNC to Meinberg 166 (I 
got it with no antenna and broken 10MHz oscillator):

https://www.dropbox.com/sh/n4lob51pzs236wb/AABy7DVGxX4EIaazizGaAx5Na?dl=0





-Arthur



Ramppa



--
 Rami VainioOH2LIY
 Email : rami.vai...@gmail.com
 Phone : +358 40 505 8085
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Re: [time-nuts] another gpsdo

[Richard W. Solomon]

There was a caveat on the page about some relationship between the two outputs, 
But there wasn't any specifics.

How does one see what the limitations are ?

Tnx, Dick, W1KSZ

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Gregory Beat
Sent: Friday, October 09, 2015 9:29 AM
To: time-nuts@febo.com; d...@montana.com
Subject: Re: [time-nuts] another gpsdo

Some additional information from Don, AJ7LL post on new GPS product.

This is what Bill, AA7XT (new Force12) posted on his Blog, 3 weeks ago.

Ultra-accurate GPS-Locked Precision Frequency Reference 
http://www.force12inc.com/pages/blog.htmlultraaccurate-gpslocked-precision-frequency-reference-now-in-stock/

Many SDR radios, transverters and other precision devices in the ham shack can 
be made even more precise when locked to an external frequency reference.  We 
recently came across an ultra-accurate GPS-locked Precision Frequency Reference 
made in England by Leo Bodnar Electronics with two programmable low-jitter 
outputs at a great price. We immediately ordered a batch that just arrived at 
our Colorado warehouse.

More info on product page:  
http://www.force12inc.com/products/gps-locked-prec...

The digital PLL allows the two output frequency references to be set to almost 
any value between 450-Hz and 800-MHz (each output can be set to a different 
frequency). Measured phase noise falls to -144-dBc/Hz @ 1-MHz and then becomes 
essentially too low to measure at higher frequencies.

---

w9gb

===

Sent from iPad Air
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Re: [time-nuts] UBLOX LEA-5T Programming?

[Bob Camp]

Hi

The PPS out of the GPS has a number of issues short term. Without sawtooth 
correction it likely is hopping and bopping 5 or 10 ns each second. Looked at as
frequency, the 1 Hz is +/- many ppb. 

The “frequency” output inherits this problem and adds the issues associated 
with pulse
drop frequency synthesis. More or less 10 MHz is a 16 MHz pulse train with 6 
our of 16 
edges dropped out. That does not give you a clean spectrum or a predictable 
signal. 

Combine these two things and you have a signal that most PLL chips will be a 
bit bothered by
*and* a reference that is much less stable than the OCXO. The answer is to 
stretch out the 
comparison process to 100’s of seconds and to use sawtooth correction. Both of 
these things
are easily done with a  < $2 MCU. The gotcha is that you need code to go with 
it. 

A $25 Ref-0 with the same GPS and a (now) documented MCU will do the same thing 
as
any other GPSDO. That sort of sets an upper limit on how much you probably 
should spend
on this sort of thing. That’s not to say that similar logic *does* put an upper 
limit, as I’ve proven on a
large number of projects I’ve done …..

Bob

> On Oct 9, 2015, at 10:16 AM, Clint Jay  wrote:
> 
> I am still learning and want to understand, if the PPS is good then why is
> the programmable output bad, as I understand it thus far, the PPS is
> derived from the same clock source or have I got that badly wrong?
> 
> On 9 October 2015 at 12:16, Bob Camp  wrote:
> 
>> Hi
>> 
>> Doing a GPSDO by locking to the awful 10 MHz output from any of these GPS
>> modules
>> is not going to work very well. Given the very long time constants
>> involved in a GPSDO
>> control loop, doing it without code is going to be pretty difficult.
>> 
>> A much easier approach:
>> 
>> Grab the GPS PPS and a scope. Use it to set the Lucent boxes on frequency.
>> Repeat the process
>> once a week.  The direct lock will flop around by (likely many) ppb. Your
>> manual set will probably keep it
>> under 1 ppb for a week.
>> 
>> Bob
>> 
>>> On Oct 9, 2015, at 1:39 AM, Perry Sandeen via time-nuts <
>> time-nuts@febo.com> wrote:
>>> 
>>> Hi,
>>> I have six of the older style (anodized solid aluminum case) Lucent
>> crystal oscillators that I’d like to turn into simple 10 MHZ output
>> GPSDO’s. I have some salvaged HP cases so I can have a linear PS and all
>> other stuff in one package.
>>> I’ve found two different choices of GPS relatively low cost units on
>> Ebay.
>>> One is a LUCENT M12+ GPS Timing Receiver W/100 Hz output  for  $19.99
>> Item 171886538138.
>>> The other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp ser
>> with two 1 PPS outputs for $49.90. Item 251785217093.
>>> IIRC, one output of a Ublox can be set to a 10 MHz.
>>> Can this model be set to have a 10 MHz output and is it easily done from
>> a PC? I have no coding ability.
>>> For more money I’d get a simpler phase detector circuit, which is all
>> I’m looking for. For less money I’d have to build more circuitry.
>>> A factor I don’t know is if the ublox is that much better/newer to
>> justify the price difference.
>>> I already have packed away two Oncore units with either a 1 KHz or 10
>> KHz output.
>>> Suggestions welcomed.
>>> Regards,
>>> Perrier
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
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>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>> 
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>> 
> 
> 
> 
> -- 
> Clint.
> 
> *No trees were harmed in the sending of this mail. However, a large number
> of electrons were greatly inconvenienced.*
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[time-nuts] 8th Symposium on Frequency Standards and Metrology

[Magnus Danielson]

Fellow time-nuts,

Next week is filled with interesting stuff as we gather in Potsdam for this:

https://www.ptb.de/8fsm2015/about-the-symposium/

I and Attila will be there, so who will join us?

PS. For the moment I actually don't know how many Cs-clocks I have... 
it's complicated.


Cheers,
Magnus
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Re: [time-nuts] Redundant GPSDO configuration / hardware

[Bob Camp]

Hi

There are an enormous number of branches and twists in coming up with a “zero 
failure”
system. 

One of many:

If the system uses GPS (or any GNSS) *and* Joe pulls up with a GPS jammer in 
his truck, all GPS
systems go off the air. If Joe parks in the parking lot for a few weeks, the 
systems 
are all down for that period of time….. 

Unfortunately this sort of thing *does* happen. It may actually be more likely 
than some of the 
other sorts of failures you have on your list. If your system is something that 
is likely to be 
deliberately attacked (military drone), then it’s actually a pretty likely 
thing. 

Bob

> On Oct 9, 2015, at 4:36 PM, skipp Isaham via time-nuts  
> wrote:
> 
> Redundant GPSDO configuration / hardware  
> 
> Hello to the Group, 
> 
> I realize integrated redundant GPSDO systems are available. If I wanted to 
> obtain a near zero failure down time using (dual) separate GPSDO hardware, is 
> there a conventional or practical method to integrate or construct a hot 
> standby 
> system from hardware not originally part of an integrated package/system? An 
> example might be the use of different brand or model GPSDO hardware. 
> 
> If a popular method is used to integrate two separate GPSDO outputs in to 
> a practical hot standby system, I would appreciate reading your suggestions 
> and information. Even comments about obtaining GPSDO output for a control 
> system that simply can not fail while in regular service/operation. 
> 
> Thank you in advance for your replies. 
> 
> 
> Regards, 
> 
> Skipp 
> 
> skipp025 at yahoo dot com 
> 
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[time-nuts] UBLOX LEA-5T Programming?

[Perry Sandeen via time-nuts]

Hi,
I have six of the older style (anodized solid aluminum case) Lucent crystal 
oscillators that I’d like to turn into simple 10 MHZ output GPSDO’s. I have 
some salvaged HP cases so I can have a linear PS and all other stuff in one 
package.
I’ve found two different choices of GPS relatively low cost units on Ebay. 
One is a LUCENT M12+ GPS Timing Receiver W/100 Hz output  for  $19.99 Item 
171886538138.
The other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp ser with 
two 1 PPS outputs for $49.90. Item 251785217093.
IIRC, one output of a Ublox can be set to a 10 MHz.
Can this model be set to have a 10 MHz output and is it easily done from a PC? 
I have no coding ability.
For more money I’d get a simpler phase detector circuit, which is all I’m 
looking for. For less money I’d have to build more circuitry.
A factor I don’t know is if the ublox is that much better/newer to justify the 
price difference.
I already have packed away two Oncore units with either a 1 KHz or 10 KHz 
output.
Suggestions welcomed.
 Regards,
Perrier
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Re: [time-nuts] Lucent RTFG-u DE-9 connectors

[Hal Murray]

golgarfrinc...@gmail.com said:
> I saw a lot of these quick locking connector shells on industrial routing
> equipment in the 1990s and hated them. 

They were part of the early Ethernet specs.  That was back in the days of 1/2 
inch coax, vampire taps, transcievers, and drop cables.  They got a horrible 
reputation for being unreliable because a major vendor of workstations but an 
extra washer in the stack.  (Or something like that.  It was a long time ago.)

-- 
These are my opinions.  I hate spam.



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Re: [time-nuts] Lucent RTFG-u DE-9 connectors

[Robert LaJeunesse]

Looks like what I call a slide latch

https://www.google.com/search?rlz=1CAACAC_enUS590US590_sm=122=1366=631=isch=1=d-sub+slide+latch=d-sub+slide+latch_l=img.12...0.0.0.208917.0.0.0.0.0.0.0.0..0.0.ccynfh...0...1..64.img..0.0.0.kopFXhwkvbM

Readily available parts at DigiKey, Mouser, etc.

http://www.digikey.com/product-search/en?pv184=2453=fff40016%2Cfff8037b=d-sub+slide+latch=0=0=0=1=0=0=0=25

Bob LaJeunesse

> Sent: Thursday, October 08, 2015 at 4:52 PM
> From: "Alexander Huemer" 
> To: time-nuts@febo.com
> Subject: [time-nuts] Lucent RTFG-u DE-9 connectors
>
> Hi,
> 
> on the Lucent RTFG-u units there are two types of D-subminiature 9 pin 
> connectors. The common, threaded type and some other type with a 
> different kind of fastening technique I have never seen before.
> Does this other type have a name? Where can I buy such connectors?
> Of course I can modify the housing of the units and equip it with 
> standard connectors, but I have too much respect for the construction to 
> do that :)
> 
> Kind regards,
> -Alex
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Re: [time-nuts] Lucent RTFG-u DE-9 connectors

[Alexander Huemer]

Hi!

On Thu, Oct 08, 2015 at 10:52:37PM +0200, Alexander Huemer wrote:
> on the Lucent RTFG-u units there are two types of D-subminiature 9 pin 
> connectors. The common, threaded type and some other type with a 
> different kind of fastening technique I have never seen before.
> Does this other type have a name? Where can I buy such connectors?
> Of course I can modify the housing of the units and equip it with 
> standard connectors, but I have too much respect for the construction to 
> do that :)

Thanks for all the answers.
With these search terms ('slide lock' and 'slide latch') I was able to 
find quite a number of available connectors one can buy.
Interestingly I was not able to find ready made cables that already have 
one of these connectors mounted.
Don't get me wrong, I am able to assemble one myself, I just found it 
interesting that there there are no cables with this connector out 
there.

Thanks again.

Kind regards,
-Alex


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Re: [time-nuts] another gpsdo

[Gregory Beat]

Some additional information from Don, AJ7LL post on new GPS product.

This is what Bill, AA7XT (new Force12) posted on his Blog, 3 weeks ago.

Ultra-accurate GPS-Locked Precision Frequency Reference 
http://www.force12inc.com/pages/blog.htmlultraaccurate-gpslocked-precision-frequency-reference-now-in-stock/

Many SDR radios, transverters and other precision devices in the ham shack can 
be made even more precise when locked to an external frequency reference.  We 
recently came across an ultra-accurate GPS-locked Precision Frequency Reference 
made in England by Leo Bodnar Electronics with two programmable low-jitter 
outputs at a great price. We immediately ordered a batch that just arrived at 
our Colorado warehouse.

More info on product page:  
http://www.force12inc.com/products/gps-locked-prec...

The digital PLL allows the two output frequency references to be set to almost 
any value between 450-Hz and 800-MHz (each output can be set to a different 
frequency). Measured phase noise falls to -144-dBc/Hz @ 1-MHz and then becomes 
essentially too low to measure at higher frequencies.

---

w9gb

===

Sent from iPad Air
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Re: [time-nuts] UBLOX LEA-5T Programming?

[Mike Cook]

> Le 9 oct. 2015 à 16:16, Clint Jay  a écrit :
> 
> I am still learning and want to understand, if the PPS is good then why is
> the programmable output bad, as I understand it thus far, the PPS is
> derived from the same clock source or have I got that badly wrong?

Yes, the same clock, BUT the output signal rising edge is aligned with the 
nearest internal clock pulse leading edge, as is the 1PPS output, which gives 
rise to something called quantization error. If the configured frequency is an 
integral division of the cpu clock, then OK, but if it is not then this error 
is apparent. IIRC,  the on board cpu oscillator is 48MHz, and so an 8MHz output 
will be OK, but 10MHz does not divide evenly into 48Mz so you get significant 
jitter.  

There is a nice Ublox doc «  Timing_AppNote_(GPS.G6-X-11007).pdf » illustrating 
this. I don’t know if there was one issued for the 5T receiver, but the 
principle is the 
same. Google should find it.


> 
> On 9 October 2015 at 12:16, Bob Camp  wrote:
> 
>> Hi
>> 
>> Doing a GPSDO by locking to the awful 10 MHz output from any of these GPS
>> modules
>> is not going to work very well. Given the very long time constants
>> involved in a GPSDO
>> control loop, doing it without code is going to be pretty difficult.
>> 
>> A much easier approach:
>> 
>> Grab the GPS PPS and a scope. Use it to set the Lucent boxes on frequency.
>> Repeat the process
>> once a week.  The direct lock will flop around by (likely many) ppb. Your
>> manual set will probably keep it
>> under 1 ppb for a week.
>> 
>> Bob
>> 
>>> On Oct 9, 2015, at 1:39 AM, Perry Sandeen via time-nuts <
>> time-nuts@febo.com> wrote:
>>> 
>>> Hi,
>>> I have six of the older style (anodized solid aluminum case) Lucent
>> crystal oscillators that I’d like to turn into simple 10 MHZ output
>> GPSDO’s. I have some salvaged HP cases so I can have a linear PS and all
>> other stuff in one package.
>>> I’ve found two different choices of GPS relatively low cost units on
>> Ebay.
>>> One is a LUCENT M12+ GPS Timing Receiver W/100 Hz output  for  $19.99
>> Item 171886538138.
>>> The other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp ser
>> with two 1 PPS outputs for $49.90. Item 251785217093.
>>> IIRC, one output of a Ublox can be set to a 10 MHz.
>>> Can this model be set to have a 10 MHz output and is it easily done from
>> a PC? I have no coding ability.
>>> For more money I’d get a simpler phase detector circuit, which is all
>> I’m looking for. For less money I’d have to build more circuitry.
>>> A factor I don’t know is if the ublox is that much better/newer to
>> justify the price difference.
>>> I already have packed away two Oncore units with either a 1 KHz or 10
>> KHz output.
>>> Suggestions welcomed.
>>> Regards,
>>> Perrier
>>> ___
>>> 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.
>> 
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>> and follow the instructions there.
>> 
> 
> 
> 
> -- 
> Clint.
> 
> *No trees were harmed in the sending of this mail. However, a large number
> of electrons were greatly inconvenienced.*
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"The main function of a modern police force is filling in forms."
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Re: [time-nuts] UBLOX LEA-5T Programming?

[Bert Kehren via time-nuts]

The 1 pps and the output frequencies are all derived from the same XO in  
the module. Up to 7 the difference in a T is that the saw tooth correction  
factor is brought out for correction purposes . 7 has a much higher XO  
frequency than the 5 so the saw tooth is smaller. So use a ublox 7 if you want  
to do a simple GPSPLL like James Miller described.  If you use the cheaper  M 
version you have to make sure you always have backup power since it does 
not  have a flash memory like the more expensive N version to memorize the  
setting Also stay away from 10 MHz out  better to use 200 or 400 KHz.  We have 
done a GPSPLL with ublox7 and Morion and got very good results. I have a  
board  if interested contact me off list.
Bert Kehren
 
 
In a message dated 10/9/2015 12:03:45 P.M. Eastern Daylight Time,  
cjaysh...@gmail.com writes:

I am  still learning and want to understand, if the PPS is good then why is
the  programmable output bad, as I understand it thus far, the PPS is
derived  from the same clock source or have I got that badly wrong?

On 9 October  2015 at 12:16, Bob Camp  wrote:

>  Hi
>
> Doing a GPSDO by locking to the awful 10 MHz output from  any of these GPS
> modules
> is not going to work very well. Given  the very long time constants
> involved in a GPSDO
> control loop,  doing it without code is going to be pretty difficult.
>
> A much  easier approach:
>
> Grab the GPS PPS and a scope. Use it to set  the Lucent boxes on 
frequency.
> Repeat the process
> once a  week.  The direct lock will flop around by (likely many) ppb.  
Your
> manual set will probably keep it
> under 1 ppb for a  week.
>
> Bob
>
> > On Oct 9, 2015, at 1:39 AM,  Perry Sandeen via time-nuts <
> time-nuts@febo.com> wrote:
>  >
> > Hi,
> > I have six of the older style (anodized  solid aluminum case) Lucent
> crystal oscillators that I’d like to turn  into simple 10 MHZ output
> GPSDO’s. I have some salvaged HP cases so I  can have a linear PS and all
> other stuff in one package.
> >  I’ve found two different choices of GPS relatively low cost units on
>  Ebay.
> > One is a LUCENT M12+ GPS Timing Receiver W/100 Hz  output  for  $19.99
> Item 171886538138.
> > The  other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp 
ser
>  with two 1 PPS outputs for $49.90. Item 251785217093.
> > IIRC, one  output of a Ublox can be set to a 10 MHz.
> > Can this model be set  to have a 10 MHz output and is it easily done 
from
> a PC? I have no  coding ability.
> > For more money I’d get a simpler phase detector  circuit, which is all
> I’m looking for. For less money I’d have to  build more circuitry.
> > A factor I don’t know is if the ublox is  that much better/newer to
> justify the price difference.
> > I  already have packed away two Oncore units with either a 1 KHz or 10
>  KHz output.
> > Suggestions welcomed.
> >   Regards,
> > Perrier
> >  ___
> > 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.
>
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>



-- 
Clint.

*No trees were  harmed in the sending of this mail. However, a large number
of electrons  were greatly  inconvenienced.*
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Re: [time-nuts] UBLOX LEA-5T Programming?

[Graham / KE9H]

There is a lot of jitter on a GPS 1 PPS output.
You need a big "flywheel" to smooth out the jitter errors.
GPS modules only have room for small flywheels.
--- Graham


On Fri, Oct 9, 2015 at 9:16 AM, Clint Jay  wrote:

> I am still learning and want to understand, if the PPS is good then why is
> the programmable output bad, as I understand it thus far, the PPS is
> derived from the same clock source or have I got that badly wrong?
>
> On 9 October 2015 at 12:16, Bob Camp  wrote:
>
> > Hi
> >
> > Doing a GPSDO by locking to the awful 10 MHz output from any of these GPS
> > modules
> > is not going to work very well. Given the very long time constants
> > involved in a GPSDO
> > control loop, doing it without code is going to be pretty difficult.
> >
> > A much easier approach:
> >
> > Grab the GPS PPS and a scope. Use it to set the Lucent boxes on
> frequency.
> > Repeat the process
> > once a week.  The direct lock will flop around by (likely many) ppb. Your
> > manual set will probably keep it
> > under 1 ppb for a week.
> >
> > Bob
> >
> > > On Oct 9, 2015, at 1:39 AM, Perry Sandeen via time-nuts <
> > time-nuts@febo.com> wrote:
> > >
> > > Hi,
> > > I have six of the older style (anodized solid aluminum case) Lucent
> > crystal oscillators that I’d like to turn into simple 10 MHZ output
> > GPSDO’s. I have some salvaged HP cases so I can have a linear PS and all
> > other stuff in one package.
> > > I’ve found two different choices of GPS relatively low cost units on
> > Ebay.
> > > One is a LUCENT M12+ GPS Timing Receiver W/100 Hz output  for  $19.99
> > Item 171886538138.
> > > The other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp
> ser
> > with two 1 PPS outputs for $49.90. Item 251785217093.
> > > IIRC, one output of a Ublox can be set to a 10 MHz.
> > > Can this model be set to have a 10 MHz output and is it easily done
> from
> > a PC? I have no coding ability.
> > > For more money I’d get a simpler phase detector circuit, which is all
> > I’m looking for. For less money I’d have to build more circuitry.
> > > A factor I don’t know is if the ublox is that much better/newer to
> > justify the price difference.
> > > I already have packed away two Oncore units with either a 1 KHz or 10
> > KHz output.
> > > Suggestions welcomed.
> > >  Regards,
> > > Perrier
> > > ___
> > > 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.
> >
> > ___
> > 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.
> >
>
>
>
> --
> Clint.
>
> *No trees were harmed in the sending of this mail. However, a large number
> of electrons were greatly inconvenienced.*
> ___
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Re: [time-nuts] UBLOX LEA-5T Programming?

[Clint Jay]

I am still learning and want to understand, if the PPS is good then why is
the programmable output bad, as I understand it thus far, the PPS is
derived from the same clock source or have I got that badly wrong?

On 9 October 2015 at 12:16, Bob Camp  wrote:

> Hi
>
> Doing a GPSDO by locking to the awful 10 MHz output from any of these GPS
> modules
> is not going to work very well. Given the very long time constants
> involved in a GPSDO
> control loop, doing it without code is going to be pretty difficult.
>
> A much easier approach:
>
> Grab the GPS PPS and a scope. Use it to set the Lucent boxes on frequency.
> Repeat the process
> once a week.  The direct lock will flop around by (likely many) ppb. Your
> manual set will probably keep it
> under 1 ppb for a week.
>
> Bob
>
> > On Oct 9, 2015, at 1:39 AM, Perry Sandeen via time-nuts <
> time-nuts@febo.com> wrote:
> >
> > Hi,
> > I have six of the older style (anodized solid aluminum case) Lucent
> crystal oscillators that I’d like to turn into simple 10 MHZ output
> GPSDO’s. I have some salvaged HP cases so I can have a linear PS and all
> other stuff in one package.
> > I’ve found two different choices of GPS relatively low cost units on
> Ebay.
> > One is a LUCENT M12+ GPS Timing Receiver W/100 Hz output  for  $19.99
> Item 171886538138.
> > The other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp ser
> with two 1 PPS outputs for $49.90. Item 251785217093.
> > IIRC, one output of a Ublox can be set to a 10 MHz.
> > Can this model be set to have a 10 MHz output and is it easily done from
> a PC? I have no coding ability.
> > For more money I’d get a simpler phase detector circuit, which is all
> I’m looking for. For less money I’d have to build more circuitry.
> > A factor I don’t know is if the ublox is that much better/newer to
> justify the price difference.
> > I already have packed away two Oncore units with either a 1 KHz or 10
> KHz output.
> > Suggestions welcomed.
> >  Regards,
> > Perrier
> > ___
> > 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.
>
> ___
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> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Clint.

*No trees were harmed in the sending of this mail. However, a large number
of electrons were greatly inconvenienced.*
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Re: [time-nuts] UBLOX LEA-5T Programming?

[Bob Camp]

Hi

Doing a GPSDO by locking to the awful 10 MHz output from any of these GPS 
modules
is not going to work very well. Given the very long time constants involved in 
a GPSDO 
control loop, doing it without code is going to be pretty difficult. 

A much easier approach:

Grab the GPS PPS and a scope. Use it to set the Lucent boxes on frequency. 
Repeat the process 
once a week.  The direct lock will flop around by (likely many) ppb. Your 
manual set will probably keep it
under 1 ppb for a week. 

Bob

> On Oct 9, 2015, at 1:39 AM, Perry Sandeen via time-nuts  
> wrote:
> 
> Hi,
> I have six of the older style (anodized solid aluminum case) Lucent crystal 
> oscillators that I’d like to turn into simple 10 MHZ output GPSDO’s. I have 
> some salvaged HP cases so I can have a linear PS and all other stuff in one 
> package.
> I’ve found two different choices of GPS relatively low cost units on Ebay. 
> One is a LUCENT M12+ GPS Timing Receiver W/100 Hz output  for  $19.99 Item 
> 171886538138.
> The other is a UBLOX LEA-5T GPS module dev board 1PPS /USB/RS232/ntp ser with 
> two 1 PPS outputs for $49.90. Item 251785217093.
> IIRC, one output of a Ublox can be set to a 10 MHz.
> Can this model be set to have a 10 MHz output and is it easily done from a 
> PC? I have no coding ability.
> For more money I’d get a simpler phase detector circuit, which is all I’m 
> looking for. For less money I’d have to build more circuitry.
> A factor I don’t know is if the ublox is that much better/newer to justify 
> the price difference.
> I already have packed away two Oncore units with either a 1 KHz or 10 KHz 
> output.
> Suggestions welcomed.
>  Regards,
> Perrier
> ___
> 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.

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[time-nuts] another gpsdo

[Don Latham]

http://www.force12inc.com/products/gps-locked-precision-frequency-reference-low-jitter-gps-clock-450-hz-to-800-mhz-output.html

Don

-- 
Felix qui potuit rerum cognoscere causas.
Lucky is he who has been able to understand the causes of things.
Virgil
---
"Noli sinere nothos te opprimere"

Dr. Don Latham, AJ7LL
Six Mile Systems LLC, 17850 Six Mile Road
Huson, MT, 59846
mailing address:  POBox 404
Frenchtown MT 59834-0404

VOX 406-626-4304
CEL 406-241-5093
Skype: buffler2
www.lightningforensics.com
www.sixmilesystems.com


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