Re: [time-nuts] When NTP goes wrong...

[Paul]

On Sat, Oct 24, 2015 at 6:36 AM, Florian Teply  wrote:

> Am Wed, 21 Oct 2015 22:54:15 -0700
> schrieb Rob Seaman :
>
> > The Network Time Foundation (through Harlan Stenn’s hard work) has
> > already released a patch synchronized with the publication of the
> > referenced paper from Boston University:
>

By the way, if you're running a public facing instance (client or server)
the patches in 4.2.8p4 and 4.3.76 are  incomplete and don't fix the worst
potential problem.   If you're concerned about the rate limiting attacks
the current best practice is to firewall and disable rate limiting.  There
are follow-up patches floating about if you want to attempt to resolve the
problem locally

In my opinion, it would be interesting to know if other implementations
> are affected as well.
>

Any implementation that does spoof-able rate limiting can be attacked.  I
don't see any mention of that in the OpenBSD conf file nor any mention in
the ntimed on github.


> But if I read that article on ars technica correctly, it looks like it
> is something inherent to the ntp protocol itself and the definitions it
> makes.
>

There are various programs that can exchange packets with an Network Time
Foundation (NTF) ntpd (ntimed, openntpd, chrony, sntp  etc. etc.) but that
don't implement the many many features in the NTF versions.   Perhaps
that's why none of those programs call themselves ntpd.

Interested parties can follow this on the ntp-pool and ntp-hackers lists.
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Re: [time-nuts] Unified VCXO Carrier Board

[Charles Steinmetz]

Bruce wrote:


The comparator circuit measured was the front end of David Partridge's
divider. I merely measured the 10MHz output.


The MAX999 and ADCMP600 are the two comparator options noted on 
David's schematic.  Both parts suffer from a number of the design and 
die-level issues I noted in my previous message, and I have never 
obtained particularly good PN with either one.  Also, even the 
relatively direct path to the 10MHz output goes through two 'AC04 
inverters and an 'AC541 line driver, which contribute additional PN.



One thing that I have found is that at low offset frequencies the measured
PN is substantially reduced when air currents and other sources of thermal
fluctuations are reduced. Even the effect of a thin piece of paper used as
an air current shield can be easily seen.
With careful shielding from thermal fluctuations I measure the low
frequency offset PN to be substantially lower than the datasheet values.
I've seen this effect with everything for which I've measured the PN.


Agreed.  Whether or not it is explicitly stated, I take "all 
circuitry to be enclosed and protected from drafts, and allowed to 
stabilize thermally before testing" as a given with any sensitive 
time or voltage circuit.



One problem with comparators when attempting to measure their PN is
that they don't have sufficient output to drive the TimePod input directly.
An amplifier is required.


The spec sheet says both TimePod inputs accept -5 to +20dBm into 50 
ohms.  -5dBm is less than 0.4Vp-p, which requires less than +/-4mA 
from the source, so a 0-5v comparator output feeding a coupling 
capacitor and a 560 ohm series resistor should work fine as long as 
the comparator can source and sink at least 4mA.


Alternatively, a 0-5v comparator output could be buffered with three 
'AC04 inverters in parallel, or an 'AC line driver -- but that adds 
the PN of the gates.



A resistor from point A to ground in the Wenzel style shaper you attached
has little effect on the output symmetry due to C4.


It has just enough effect to correct the very small (<1%) asymmetry 
due to the unbalanced drive.  (With no resistor at Point A, the duty 
cycle is ~51%/49% high/low.)



However it does allow the output amplitude to be adjusted.


According to the simulation, the resistor has no effect on the output 
amplitude until it is well below 1k ohms (at 1k ohm, the symmetry has 
been WAY overcompensated and the duty cycle is ~45%/55% high/low.


Best regards,

Charles


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Re: [time-nuts] Unified VCXO Carrier Board

[Charles Steinmetz]

The schematic I posted yesterday of the optimized Wenzel-style 
squarer did not specify capacitor types for C1, C3, and C4.  All 
three should be C0G/NP0, and C4 *must* be C0G/NP0.  The attached 
schematic is revised accordingly.


Best regards,

Charles
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Re: [time-nuts] 10811 unsoldered fuse

[Luca Dal Passo]

Hi,
the PCB is a "single side" type, and from the "component side" of the pcb
you can see the two little holes, because are visible the metal rings that
lock them to the board on that side (they are soldered on the copper side
only). Other component's wires simply go to normal holes on the pcb.
Luca



Il sabato 24 ottobre 2015, Dimitri.p  ha scritto:

> Are they visible from the same side as the thermal fuse and the IC or are
> they under the board  so you can only see them once you start taking the
> boards apart ?
>
> Thanks,
> Dimitri
>
>
> At 11:48 PM 10/23/2015, Luca Dal Passo wrote:
>
>> Hi all,
>>i have on my desk a disassembled 10811 for service. It has a thermal
>> fuse of the rectangular black type placed just above the IC. The leads are
>> plugged into two very small sockets on the pcb, they are not soldered.
>> Bye
>> Luca
>> iw2Lje
>>
>>
>>
>> Il giovedì 22 ottobre 2015, J. L. Trantham  ha scritto:
>>
>> > David,
>> >
>> > Good to know.  Thanks for the info.  Any idea of a source for that part?
>> >
>> > I don't remember whether my fuse was soldered in or plugged in.
>> Whatever
>> > it was, I replaced it the same way.
>> >
>> > Thanks again.
>> >
>> > Joe
>> >
>> > -Original Message-
>> > From: time-nuts [mailto:time-nuts-boun...@febo.com ] On
>> > Behalf Of David G. McGaw
>> > Sent: Wednesday, October 21, 2015 10:02 AM
>> > To: Discussion of precise time and frequency measurement
>> > Subject: [Bulk] Re: [time-nuts] [Bulk] 10811 unsoldered fuse
>> >
>> > That probably is an original thermal cutout.  It matches ones I have
>> found
>> > when repairing 10811As.
>> >
>> > David
>> >
>> >
>> > On 10/20/15 7:59 AM, J. L. Trantham wrote:
>> > > Dimitri,
>> > >
>> > > That clearly is not the 'original' thermal fuse that I found in my
>> 10811.
>> > > Mine was a small, axial lead, cylindrical part.
>> > >
>> > > It looks like someone substituted a different part (is that a fuse or
>> > > a
>> > > cutoff?) and did a poor job soldering.  I think the temperature is
>> > > correct though.  I'd have to look at the manual to know for sure.
>> > >
>> > > My 'fuse' failed and I replaced it.  All the soldering was OK on my
>> unit.
>> > >
>> > > Joe
>> > >
>> > > -Original Message-
>> > > From: time-nuts [mailto:time-nuts-boun...@febo.com ] On
>> > Behalf Of
>> > > Dimitri.p
>> > > Sent: Monday, October 19, 2015 2:32 PM
>> > > To: time-nuts@febo.com 
>> > > Subject: [Bulk] [time-nuts] 10811 unsoldered fuse
>> > >
>> > > How common is it to find undetected missing solder on 10811 parts
>> > > after all these years?
>> > >
>> > > Dimitri
>> > >
>> > > ___
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>> >
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Re: [time-nuts] When NTP goes wrong...

[Bob Camp]

Hi

Without the real paper(s) they are referencing, it’s impossible to evaluate 
what they
are saying. In order to actually address their points, it will have to be done 
on a paper
by paper basis. 

Bob

> On Oct 24, 2015, at 6:36 AM, Florian Teply  wrote:
> 
> Am Wed, 21 Oct 2015 22:54:15 -0700
> schrieb Rob Seaman :
> 
>> Mark Sims said:
>> 
>>> Ars Technica just put up a piece on the effects of various attacks
>>> on NTP with a link to the original paper.
>>> 
>>> http://arstechnica.com/security/2015/10/new-attacks-on-network-time-protocol-can-defeat-https-and-create-chaos/
>> 
>> 
>> The Network Time Foundation (through Harlan Stenn’s hard work) has
>> already released a patch synchronized with the publication of the
>> referenced paper from Boston University:
>> 
>>  http://nwtime.org/ntf-releases-ntp-security-patches-ntp-4-2-8p4/
>> 
>> Many of the comments on the Ars Technica piece are quite naive
>> regarding timekeeping issues. This reflects an ongoing need for
>> public education that Time-nuts as well as NTF can help supply.
>> 
> In my opinion, it would be interesting to know if other implementations
> are affected as well.
> Until now, I've come across the ntp mentioned above, maintained by
> the network time foundation.
> But there's also openntpd, maintained by the OpenBSD guys, and ntimed
> by PHK, which IIRC both claim to address security. Likely there afre
> even more out there...
> 
> But if I read that article on ars technica correctly, it looks like it
> is something inherent to the ntp protocol itself and the definitions it
> makes.
> 
> Poul-Henning, would you care to comment on that for ntimed?
> 
> Best regards,
> Florian
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Re: [time-nuts] When NTP goes wrong...

[Magnus Danielson]

Bob,

It was linked from the article. Some 18 pages of reading. Go and read 
it. I will when I get the time... can somebody skew my time by skew my 
NTP? Just read the article, it tells you how to pull it off.


Cheers,
Magnus

On 10/24/2015 03:02 PM, Bob Camp wrote:

Hi

Without the real paper(s) they are referencing, it’s impossible to evaluate 
what they
are saying. In order to actually address their points, it will have to be done 
on a paper
by paper basis.

Bob


On Oct 24, 2015, at 6:36 AM, Florian Teply  wrote:

Am Wed, 21 Oct 2015 22:54:15 -0700
schrieb Rob Seaman :


Mark Sims said:


Ars Technica just put up a piece on the effects of various attacks
on NTP with a link to the original paper.

http://arstechnica.com/security/2015/10/new-attacks-on-network-time-protocol-can-defeat-https-and-create-chaos/



The Network Time Foundation (through Harlan Stenn’s hard work) has
already released a patch synchronized with the publication of the
referenced paper from Boston University:

http://nwtime.org/ntf-releases-ntp-security-patches-ntp-4-2-8p4/

Many of the comments on the Ars Technica piece are quite naive
regarding timekeeping issues. This reflects an ongoing need for
public education that Time-nuts as well as NTF can help supply.


In my opinion, it would be interesting to know if other implementations
are affected as well.
Until now, I've come across the ntp mentioned above, maintained by
the network time foundation.
But there's also openntpd, maintained by the OpenBSD guys, and ntimed
by PHK, which IIRC both claim to address security. Likely there afre
even more out there...

But if I read that article on ars technica correctly, it looks like it
is something inherent to the ntp protocol itself and the definitions it
makes.

Poul-Henning, would you care to comment on that for ntimed?

Best regards,
Florian
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Re: [time-nuts] Unified VCXO Carrier Board

[Hal Murray]

csteinm...@yandex.com said:
> The schematic I posted yesterday of the optimized Wenzel-style  squarer did
> not specify capacitor types for C1, C3, and C4.  All  three should be C0G/
> NP0, and C4 *must* be C0G/NP0. 

What property of those capicitors is important in that circuit?



-- 
These are my opinions.  I hate spam.



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Re: [time-nuts] GPS Disciplined TCXO

[Gregory Maxwell]

On Fri, Oct 23, 2015 at 11:08 PM, Nick Sayer via time-nuts
 wrote:
>
>> On Oct 23, 2015, at 2:09 PM, Gregory Maxwell  wrote:
>>
>> On Tue, Oct 20, 2015 at 8:53 PM, Bryan _  wrote:
>>> Saw this on the Hackaday site if anyone is interested.
>>> https://hackaday.io/project/6872-gps-disciplined-tcxo
>>
>> Will this design that uses the output of the DAC directly not run into
>> problems with non-monotonicity and/or dead-zones in the DAC output?  I
>> would expect a PLL to behave very poorly if there is any
>> non-monotonicity in the least significant bit of the DAC.
>
> The datasheet claims the DAC is inherently monotonic. It’s a $7 part, so I 
> don’t have much reason to look sideways at that claim.

Indeed!  However, the spec sheet shows (e.g. figure 10) a differential
non-linearity of 0.2 .. -0.2  LSB,  meaning that when the PLL makes a
single step the result may be 20% greater or lower than expected,
which probably isn't good for stability though not the PLL
breaking-ness of a non-monotone response.

> That strikes me as familiar - a little like how Arduino fakes analog output 
> by running PWM into an LPF.

It's a common technique, (it and ones like it) also used internally in
high bit depth DACs.

> If you look at the AD5061 datasheet, there is unfortunately a relatively 
> significant (to my eyes, at least) update glitch. I suppose it’s quick enough 
> that the RC filter would get rid of most of it, but it is an extra noise 
> source if you do it frequently, like you’re suggesting.

Ouch, that is a fairly substantial spike compared to 1lsb... it's
short at least, but if you are only updating once a second I'd wonder
if that would not have a measurable impact on stability.

A potential advantage of running at a constant high rate is that
rather than taking the impact of that glitch once per second, the
glitch happens constantly and so its effect can just be averaged out
by the PLL.  (e.g. it becomes equivalent to just scaling the output
voltage by its average effects).
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Re: [time-nuts] Unified VCXO Carrier Board

[Charles Steinmetz]

Hal wrote:


What property of those capicitors is important in that circuit?


For C4, dielectric absorption, voltage coefficient, tempco, and 
dissipation factor.


For C3, tempco, voltage coefficient, and dissipation factor.

For C2 and C1, best design practices.

Best regards,

Charles


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Re: [time-nuts] Unified VCXO Carrier Board

[Bruce Griffiths]

On Saturday, October 24, 2015 09:03:21 AM Charles Steinmetz wrote:
> Bruce wrote:
> >The comparator circuit measured was the front end of David 
Partridge's
> >divider. I merely measured the 10MHz output.
> 
> The MAX999 and ADCMP600 are the two comparator options noted on
> David's schematic.  Both parts suffer from a number of the design and
> die-level issues I noted in my previous message, and I have never
> obtained particularly good PN with either one.  Also, even the
> relatively direct path to the 10MHz output goes through two 'AC04
> inverters and an 'AC541 line driver, which contribute additional PN.
> 
> >One thing that I have found is that at low offset frequencies the 
measured
> >PN is substantially reduced when air currents and other sources of 
thermal
> >fluctuations are reduced. Even the effect of a thin piece of paper used 
as
> >an air current shield can be easily seen.
> >With careful shielding from thermal fluctuations I measure the low
> >frequency offset PN to be substantially lower than the datasheet 
values.
> >I've seen this effect with everything for which I've measured the PN.
> 
> Agreed.  Whether or not it is explicitly stated, I take "all
> circuitry to be enclosed and protected from drafts, and allowed to
> stabilize thermally before testing" as a given with any sensitive
> time or voltage circuit.
> 
> >One problem with comparators when attempting to measure their PN is
> >that they don't have sufficient output to drive the TimePod input 
directly.
> >An amplifier is required.
> 
> The spec sheet says both TimePod inputs accept -5 to +20dBm into 50
> ohms.  -5dBm is less than 0.4Vp-p, which requires less than +/-4mA
> from the source, so a 0-5v comparator output feeding a
> capacitor and a 560 ohm series resistor should work fine as long as
> the comparator can source and sink at least 4mA.
The fly in the ointment is that with such low level inputs (the LTC6957-4 
evaluation board will deliver +4dBm into 50 ohm) the Timepod phase noise 
floor is uncomfortably close to the phase noise floor of the LTC6957.
> 
> Alternatively, a 0-5v comparator output could be buffered with three
> 'AC04 inverters in parallel, or an 'AC line driver -- but that adds s
> the PN of the gates.
> 
Not if one uses a pair of drivers one to drive the Timepod Ch0 input and 
one to drive the Timepod CH2 input.
> >A resistor from point A to ground in the Wenzel style shaper you 
attached
> >has little effect on the output symmetry due to C4.
> 
> It has just enough effect to correct the very small (<1%) asymmetry
> due to the unbalanced drive.  (With no resistor at Point A, the duty
> cycle is ~51%/49% high/low.)
> 
> >However it does allow the output amplitude to be adjusted.
> 
> According to the simulation, the resistor has no effect on the output
> amplitude until it is well below 1k ohms (at 1k ohm, the symmetry has
> been WAY overcompensated and the duty cycle is ~45%/55% high/low.
> 
Not true even 10k increases the output signal amplitude by 130mV or 
2.6%.
However that is smaller than the tilt/sag in the high level output due to 
feedthrough via Cbe of the input transistor when it is off.
> Best regards,
> 
> Charles
> 
It would perhaps be useful to measure the PN characteristics of several 
comparators and other sine to square converter circuits using a Timepod 
or equivalent.


Bruce
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Re: [time-nuts] When NTP goes wrong...

[Bob Camp]

Hi

…. and that paper references a whole raft of other papers. Until you dig down 
into each of them
it’s not at all apparent what is being referred to in some sections. In some 
cases they are going back
to things in the 1990’s. A lot has changed since then. 

Bob



> On Oct 24, 2015, at 3:50 PM, Magnus Danielson  
> wrote:
> 
> Bob,
> 
> It was linked from the article. Some 18 pages of reading. Go and read it. I 
> will when I get the time... can somebody skew my time by skew my NTP? Just 
> read the article, it tells you how to pull it off.
> 
> Cheers,
> Magnus
> 
> On 10/24/2015 03:02 PM, Bob Camp wrote:
>> Hi
>> 
>> Without the real paper(s) they are referencing, it’s impossible to evaluate 
>> what they
>> are saying. In order to actually address their points, it will have to be 
>> done on a paper
>> by paper basis.
>> 
>> Bob
>> 
>>> On Oct 24, 2015, at 6:36 AM, Florian Teply  wrote:
>>> 
>>> Am Wed, 21 Oct 2015 22:54:15 -0700
>>> schrieb Rob Seaman :
>>> 
 Mark Sims said:
 
> Ars Technica just put up a piece on the effects of various attacks
> on NTP with a link to the original paper.
> 
> http://arstechnica.com/security/2015/10/new-attacks-on-network-time-protocol-can-defeat-https-and-create-chaos/
 
 
 The Network Time Foundation (through Harlan Stenn’s hard work) has
 already released a patch synchronized with the publication of the
 referenced paper from Boston University:
 
http://nwtime.org/ntf-releases-ntp-security-patches-ntp-4-2-8p4/
 
 Many of the comments on the Ars Technica piece are quite naive
 regarding timekeeping issues. This reflects an ongoing need for
 public education that Time-nuts as well as NTF can help supply.
 
>>> In my opinion, it would be interesting to know if other implementations
>>> are affected as well.
>>> Until now, I've come across the ntp mentioned above, maintained by
>>> the network time foundation.
>>> But there's also openntpd, maintained by the OpenBSD guys, and ntimed
>>> by PHK, which IIRC both claim to address security. Likely there afre
>>> even more out there...
>>> 
>>> But if I read that article on ars technica correctly, it looks like it
>>> is something inherent to the ntp protocol itself and the definitions it
>>> makes.
>>> 
>>> Poul-Henning, would you care to comment on that for ntimed?
>>> 
>>> Best regards,
>>> Florian
>>> ___
>>> 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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Re: [time-nuts] GPS Disciplined TCXO

[Bob Camp]

Hi

> On Oct 24, 2015, at 5:43 PM, Gregory Maxwell  wrote:
> 
> On Fri, Oct 23, 2015 at 11:08 PM, Nick Sayer via time-nuts
>  wrote:
>> 
>>> On Oct 23, 2015, at 2:09 PM, Gregory Maxwell  wrote:
>>> 
>>> On Tue, Oct 20, 2015 at 8:53 PM, Bryan _  wrote:
 Saw this on the Hackaday site if anyone is interested.
 https://hackaday.io/project/6872-gps-disciplined-tcxo
>>> 
>>> Will this design that uses the output of the DAC directly not run into
>>> problems with non-monotonicity and/or dead-zones in the DAC output?  I
>>> would expect a PLL to behave very poorly if there is any
>>> non-monotonicity in the least significant bit of the DAC.
>> 
>> The datasheet claims the DAC is inherently monotonic. It’s a $7 part, so I 
>> don’t have much reason to look sideways at that claim.
> 
> Indeed!  However, the spec sheet shows (e.g. figure 10) a differential
> non-linearity of 0.2 .. -0.2  LSB,  meaning that when the PLL makes a
> single step the result may be 20% greater or lower than expected,
> which probably isn't good for stability though not the PLL
> breaking-ness of a non-monotone response.
> 
>> That strikes me as familiar - a little like how Arduino fakes analog output 
>> by running PWM into an LPF.
> 
> It's a common technique, (it and ones like it) also used internally in
> high bit depth DACs.
> 
>> If you look at the AD5061 datasheet, there is unfortunately a relatively 
>> significant (to my eyes, at least) update glitch. I suppose it’s quick 
>> enough that the RC filter would get rid of most of it, but it is an extra 
>> noise source if you do it frequently, like you’re suggesting.
> 
> Ouch, that is a fairly substantial spike compared to 1lsb... it's
> short at least, but if you are only updating once a second I'd wonder
> if that would not have a measurable impact on stability.
> 
> A potential advantage of running at a constant high rate is that
> rather than taking the impact of that glitch once per second, the
> glitch happens constantly and so its effect can just be averaged out
> by the PLL.  (e.g. it becomes equivalent to just scaling the output
> voltage by its average effects).

Since the glitch energy changes with code and with transition direction, 
what happens in a a high update rate “dither” approach is that the glitches 
dominate the whole process. Effectively you have a “DC” component
that gets into the result from the glitches. 

Bob

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Re: [time-nuts] GPS Disciplined TCXO

[Nick Sayer via time-nuts]

> On Oct 24, 2015, at 2:43 PM, Gregory Maxwell  wrote:
> 
> On Fri, Oct 23, 2015 at 11:08 PM, Nick Sayer via time-nuts
>  wrote:
>> 
>>> On Oct 23, 2015, at 2:09 PM, Gregory Maxwell  wrote:
>>> 
>>> On Tue, Oct 20, 2015 at 8:53 PM, Bryan _  wrote:
 Saw this on the Hackaday site if anyone is interested.
 https://hackaday.io/project/6872-gps-disciplined-tcxo
>>> 
>>> Will this design that uses the output of the DAC directly not run into
>>> problems with non-monotonicity and/or dead-zones in the DAC output?  I
>>> would expect a PLL to behave very poorly if there is any
>>> non-monotonicity in the least significant bit of the DAC.
>> 
>> The datasheet claims the DAC is inherently monotonic. It’s a $7 part, so I 
>> don’t have much reason to look sideways at that claim.
> 
> Indeed!  However, the spec sheet shows (e.g. figure 10) a differential
> non-linearity of 0.2 .. -0.2  LSB,  meaning that when the PLL makes a
> single step the result may be 20% greater or lower than expected,
> which probably isn't good for stability though not the PLL
> breaking-ness of a non-monotone response.
> 
>> That strikes me as familiar - a little like how Arduino fakes analog output 
>> by running PWM into an LPF.
> 
> It's a common technique, (it and ones like it) also used internally in
> high bit depth DACs.
> 
>> If you look at the AD5061 datasheet, there is unfortunately a relatively 
>> significant (to my eyes, at least) update glitch. I suppose it’s quick 
>> enough that the RC filter would get rid of most of it, but it is an extra 
>> noise source if you do it frequently, like you’re suggesting.
> 
> Ouch, that is a fairly substantial spike compared to 1lsb... it's
> short at least, but if you are only updating once a second

Actually, once every 100 seconds presently.

> I'd wonder
> if that would not have a measurable impact on stability.
> 
> A potential advantage of running at a constant high rate is that
> rather than taking the impact of that glitch once per second, the
> glitch happens constantly and so its effect can just be averaged out
> by the PLL.  (e.g. it becomes equivalent to just scaling the output
> voltage by its average effects).

Well, at the risk of sounding a bit self-serving, I encourage you to give it a 
try. If you have a 3.3 volt (or target powered) AVR programmer you can modify 
the firmware and experiment with your technique. Of course, since it’s open 
hardware you don’t need to get one from me if you don’t want to.

At the moment my priorities are in getting the chassis fit and finish finalized 
(I’ve got one more PCB version to order and I think that will likely wind up 
being The One) and tuning the PLL constants better. I want to get some long 
term samples of the oscillators uncorrected so that I can run the GPSDO 
simulator to accelerate that process. At the moment my perception is that the 
feedback is… glacial…



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Re: [time-nuts] 10811 unsoldered fuse

[J. L. Trantham]

Luca,

Any identifying marks on the part?

Thanks.

Joe

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Luca Dal Passo
Sent: Saturday, October 24, 2015 1:49 AM
To: Discussion of precise time and frequency measurement
Subject: [Bulk] Re: [time-nuts] 10811 unsoldered fuse

Hi all,
   i have on my desk a disassembled 10811 for service. It has a thermal fuse of 
the rectangular black type placed just above the IC. The leads are plugged into 
two very small sockets on the pcb, they are not soldered.
Bye
Luca
iw2Lje



Il giovedì 22 ottobre 2015, J. L. Trantham  ha scritto:

> David,
>
> Good to know.  Thanks for the info.  Any idea of a source for that part?
>
> I don't remember whether my fuse was soldered in or plugged in.  
> Whatever it was, I replaced it the same way.
>
> Thanks again.
>
> Joe
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com ] On 
> Behalf Of David G. McGaw
> Sent: Wednesday, October 21, 2015 10:02 AM
> To: Discussion of precise time and frequency measurement
> Subject: [Bulk] Re: [time-nuts] [Bulk] 10811 unsoldered fuse
>
> That probably is an original thermal cutout.  It matches ones I have 
> found when repairing 10811As.
>
> David
>
>
> On 10/20/15 7:59 AM, J. L. Trantham wrote:
> > Dimitri,
> >
> > That clearly is not the 'original' thermal fuse that I found in my 10811.
> > Mine was a small, axial lead, cylindrical part.
> >
> > It looks like someone substituted a different part (is that a fuse 
> > or a
> > cutoff?) and did a poor job soldering.  I think the temperature is 
> > correct though.  I'd have to look at the manual to know for sure.
> >
> > My 'fuse' failed and I replaced it.  All the soldering was OK on my unit.
> >
> > Joe
> >
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com ] 
> > On
> Behalf Of
> > Dimitri.p
> > Sent: Monday, October 19, 2015 2:32 PM
> > To: time-nuts@febo.com 
> > Subject: [Bulk] [time-nuts] 10811 unsoldered fuse
> >
> > How common is it to find undetected missing solder on 10811 parts 
> > after all these years?
> >
> > Dimitri
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com  To
> unsubscribe, go to
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> > and follow the instructions there.
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Re: [time-nuts] 10811 unsoldered fuse

[Luca Dal Passo]

Hi all,
   i have on my desk a disassembled 10811 for service. It has a thermal
fuse of the rectangular black type placed just above the IC. The leads are
plugged into two very small sockets on the pcb, they are not soldered.
Bye
Luca
iw2Lje



Il giovedì 22 ottobre 2015, J. L. Trantham  ha scritto:

> David,
>
> Good to know.  Thanks for the info.  Any idea of a source for that part?
>
> I don't remember whether my fuse was soldered in or plugged in.  Whatever
> it was, I replaced it the same way.
>
> Thanks again.
>
> Joe
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com ] On
> Behalf Of David G. McGaw
> Sent: Wednesday, October 21, 2015 10:02 AM
> To: Discussion of precise time and frequency measurement
> Subject: [Bulk] Re: [time-nuts] [Bulk] 10811 unsoldered fuse
>
> That probably is an original thermal cutout.  It matches ones I have found
> when repairing 10811As.
>
> David
>
>
> On 10/20/15 7:59 AM, J. L. Trantham wrote:
> > Dimitri,
> >
> > That clearly is not the 'original' thermal fuse that I found in my 10811.
> > Mine was a small, axial lead, cylindrical part.
> >
> > It looks like someone substituted a different part (is that a fuse or
> > a
> > cutoff?) and did a poor job soldering.  I think the temperature is
> > correct though.  I'd have to look at the manual to know for sure.
> >
> > My 'fuse' failed and I replaced it.  All the soldering was OK on my unit.
> >
> > Joe
> >
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com ] On
> Behalf Of
> > Dimitri.p
> > Sent: Monday, October 19, 2015 2:32 PM
> > To: time-nuts@febo.com 
> > Subject: [Bulk] [time-nuts] 10811 unsoldered fuse
> >
> > How common is it to find undetected missing solder on 10811 parts
> > after all these years?
> >
> > Dimitri
> >
> > ___
> > 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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> unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
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Re: [time-nuts] When NTP goes wrong...

[Florian Teply]

Am Wed, 21 Oct 2015 22:54:15 -0700
schrieb Rob Seaman :

> Mark Sims said:
> 
> > Ars Technica just put up a piece on the effects of various attacks
> > on NTP with a link to the original paper.
> > 
> > http://arstechnica.com/security/2015/10/new-attacks-on-network-time-protocol-can-defeat-https-and-create-chaos/
> 
> 
> The Network Time Foundation (through Harlan Stenn’s hard work) has
> already released a patch synchronized with the publication of the
> referenced paper from Boston University:
> 
>   http://nwtime.org/ntf-releases-ntp-security-patches-ntp-4-2-8p4/
> 
> Many of the comments on the Ars Technica piece are quite naive
> regarding timekeeping issues. This reflects an ongoing need for
> public education that Time-nuts as well as NTF can help supply.
> 
In my opinion, it would be interesting to know if other implementations
are affected as well.
Until now, I've come across the ntp mentioned above, maintained by
the network time foundation.
But there's also openntpd, maintained by the OpenBSD guys, and ntimed
by PHK, which IIRC both claim to address security. Likely there afre
even more out there...

But if I read that article on ars technica correctly, it looks like it
is something inherent to the ntp protocol itself and the definitions it
makes.

Poul-Henning, would you care to comment on that for ntimed?

Best regards,
Florian
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Re: [time-nuts] Timelab Query (likely noob error)

[Jason Ball]

Thanks John.

Definite Noob issue.   It helps to have the counter in the correct mode as
well ;)

All working as it should be now.

Cheers
Jason.


On Sat, Oct 24, 2015 at 7:54 PM, John Miles  wrote:

>
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jason
> Ball
> > Sent: Friday, October 23, 2015 10:38 PM
> > To: Discussion of precise time and frequency measurement
> > Subject: [time-nuts] Timelab Query (likely noob error)
> >
> > Hi all,
> >
> > I'm afraid this may be a noob question as I've undoubtedly done something
> > wrong, either that or I have some phenominal time sources... more likely
> > I've made an error in an assumption or two.   This should to my mind be
> > within the capabilities of the counter I have, but right now I'm starting
> > to wonder.
> >
> > The problem is I'm seeing a 10s tau of 9.29E-18 which to my limited
> > understanding is highly doubtful.
> >
> > So what have I done wrong ?
> >
>
> Hi, Jason --
>
> Let's take a look at the .tim file (email it to j...@miles.io) --
> probably just a missing/inappropriate scale factor.
>
> -- john, KE5FX
> Miles Design LLC
>
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>



-- 
--
Teach your kids Science, or somebody else will :/

ja...@ball.net
vk2...@google.com 
callsign: vk2vjb
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Re: [time-nuts] 10811 unsoldered fuse

[Dimitri.p]

Are they visible from the same side as the 
thermal fuse and the IC or are they under the 
board  so you can only see them once you start taking the boards apart ?


Thanks,
Dimitri


At 11:48 PM 10/23/2015, Luca Dal Passo wrote:

Hi all,
   i have on my desk a disassembled 10811 for service. It has a thermal
fuse of the rectangular black type placed just above the IC. The leads are
plugged into two very small sockets on the pcb, they are not soldered.
Bye
Luca
iw2Lje



Il giovedì 22 ottobre 2015, J. L. Trantham  ha scritto:

> David,
>
> Good to know.  Thanks for the info.  Any idea of a source for that part?
>
> I don't remember whether my fuse was soldered in or plugged in.  Whatever
> it was, I replaced it the same way.
>
> Thanks again.
>
> Joe
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com ] On
> Behalf Of David G. McGaw
> Sent: Wednesday, October 21, 2015 10:02 AM
> To: Discussion of precise time and frequency measurement
> Subject: [Bulk] Re: [time-nuts] [Bulk] 10811 unsoldered fuse
>
> That probably is an original thermal cutout.  It matches ones I have found
> when repairing 10811As.
>
> David
>
>
> On 10/20/15 7:59 AM, J. L. Trantham wrote:
> > Dimitri,
> >
> > That clearly is not the 'original' thermal fuse that I found in my 10811.
> > Mine was a small, axial lead, cylindrical part.
> >
> > It looks like someone substituted a different part (is that a fuse or
> > a
> > cutoff?) and did a poor job soldering.  I think the temperature is
> > correct though.  I'd have to look at the manual to know for sure.
> >
> > My 'fuse' failed and I replaced it.  All the soldering was OK on my unit.
> >
> > Joe
> >
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com ] On
> Behalf Of
> > Dimitri.p
> > Sent: Monday, October 19, 2015 2:32 PM
> > To: time-nuts@febo.com 
> > Subject: [Bulk] [time-nuts] 10811 unsoldered fuse
> >
> > How common is it to find undetected missing solder on 10811 parts
> > after all these years?
> >
> > Dimitri
> >
> > ___
> > 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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> 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.
>
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Re: [time-nuts] Timelab Query (likely noob error)

[John Miles]

> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jason Ball
> Sent: Friday, October 23, 2015 10:38 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] Timelab Query (likely noob error)
> 
> Hi all,
> 
> I'm afraid this may be a noob question as I've undoubtedly done something
> wrong, either that or I have some phenominal time sources... more likely
> I've made an error in an assumption or two.   This should to my mind be
> within the capabilities of the counter I have, but right now I'm starting
> to wonder.
> 
> The problem is I'm seeing a 10s tau of 9.29E-18 which to my limited
> understanding is highly doubtful.
> 
> So what have I done wrong ?
> 

Hi, Jason --

Let's take a look at the .tim file (email it to j...@miles.io) -- probably just 
a missing/inappropriate scale factor.

-- john, KE5FX
Miles Design LLC

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