GPS change coming on April 6

[Soartech]

Just saw this:

Subject: [UKMicrowaves] GPS Frequency standards.. Week Zero alert.
Date: Thu, 7 Feb 2019 18:39:05 -0000
From: Mark GM4ISM



For those of us reliant on GPS based frequency standards and location
systems, there is an upcoming event that may upset some GPS engines.

GPS week numbers only go up to 1024 and we hit another 'week zero' event
on 6th April this year.

This can and does cause some older GPS engines to become rather upset.
Some completely loose lock, some may still produce 1 PPS etc but output
the wrong date and time
Many of these recover at week 1 but that is not guaranteed.

Some testing has been done by a colleague on a number of GPS based
systems using a locally generated GPS signal set that simulates the week
zero signals.
A number of older GPS engines have failed this test and the frequency
standards associated with them have been shown to go into holdover and
start to drift....
Amongst the ones likely to fall over are the Rockwell chipset widely
used by amateurs. The exact model with 10KHz (Jupiter) out has not been
confirmed but pretty much all of the related models, used in a number of
GPS disciplined oscillators, fell over.
The Jupiter in my old RUH system already needs a poke of serial data at
start-up, I believe to correct a previous timestamp rollover. I guess it
may need a different one soon.
I am aware that if all else fails, UBlox GPS engines have been
successfully used in the RUH design standard in place of the Jupiter, as
some Ublox engines can be programmed to output the required 10KHz
instead of 1PPS
All (slightly older ) UBlox modules that have been tested were
unaffected so it is likely that newer ones will be OK too,

Some older Rapco GPS standards fail the Week Zero test which makes them
think they are the best part of twenty years younger. Their recovery
into week 1 is not certain.

I am aware that at least one model of these has an internal firmware
week counter which will rollover in July if I recall, further
complicating matters
I also have one of these and its useful life is now in question.

The Trimble Palisades out there are an unknown quantity.
I will try to get one tested. I use one of these with a VE2ZAZ system
and so does GB3CSB



Recovery in week 1 has not been tested in my world, a full week in
holdover is not acceptable so units are being replaced.


So the upshot is that for the duration of week 0, your GPS freq
standard, if based round an older GPS engine, may fail to lock and
provide an accurate 10MHz
I have a Rubidium standalone, which I fear I may need because none of my
references are modern.


You may see people flogging off some professional GPS frequency
standards. Some may be real bargains if there is a 'fix', other may
become simply a source of a reasonable 10MHz OCXO Caveat emptor!


Happy Binary Birthday GPS!

[Tim Newport-Peace[_4_]]

Known issue, see http://tinyurl.com/y56n8odz

If it will effect your Flight Recorder depends on:

1. The ago of the GPS Engine in your recorder.
2. The condition of the RTC battery in the GPS Engine.

After 6th April 2019, you can check the date by downloading a flight made
after 6th April 2019 and opening the .IGC file with a text editor, such as
Wordpad. Within the first few records you will find a line beginning
“HFDTE” followed by a date, if this is the date of the flight, then you
are fine, otherwise you have a problem. Talk to your dealer.

At 14:22 24 February 2019, Soartech wrote:
>Just saw this:
>
>Subject: [UKMicrowaves] GPS Frequency standards.. Week Zero alert.
>Date: Thu, 7 Feb 2019 18:39:05 -0000
>From: Mark GM4ISM
>
>
>
>For those of us reliant on GPS based frequency standards and location
>systems, there is an upcoming event that may upset some GPS engines.
>
>GPS week numbers only go up to 1024 and we hit another 'week zero' event
>on 6th April this year.
>
>This can and does cause some older GPS engines to become rather upset.
>Some completely loose lock, some may still produce 1 PPS etc but output
>the wrong date and time
>Many of these recover at week 1 but that is not guaranteed.
>
>Some testing has been done by a colleague on a number of GPS based
>systems using a locally generated GPS signal set that simulates the week
>zero signals.
>A number of older GPS engines have failed this test and the frequency
>standards associated with them have been shown to go into holdover and
>start to drift....
>Amongst the ones likely to fall over are the Rockwell chipset widely
>used by amateurs. The exact model with 10KHz (Jupiter) out has not been
>confirmed but pretty much all of the related models, used in a number of
>GPS disciplined oscillators, fell over.
>The Jupiter in my old RUH system already needs a poke of serial data at
>start-up, I believe to correct a previous timestamp rollover. I guess it
>may need a different one soon.
>I am aware that if all else fails, UBlox GPS engines have been
>successfully used in the RUH design standard in place of the Jupiter, as
>some Ublox engines can be programmed to output the required 10KHz
>instead of 1PPS
>All (slightly older ) UBlox modules that have been tested were
>unaffected so it is likely that newer ones will be OK too,
>
>Some older Rapco GPS standards fail the Week Zero test which makes them
>think they are the best part of twenty years younger. Their recovery
>into week 1 is not certain.
>
>I am aware that at least one model of these has an internal firmware
>week counter which will rollover in July if I recall, further
>complicating matters
>I also have one of these and its useful life is now in question.
>
>The Trimble Palisades out there are an unknown quantity.
>I will try to get one tested. I use one of these with a VE2ZAZ system
>and so does GB3CSB
>
>
>
>Recovery in week 1 has not been tested in my world, a full week in
>holdover is not acceptable so units are being replaced.
>
>
>So the upshot is that for the duration of week 0, your GPS freq
>standard, if based round an older GPS engine, may fail to lock and
>provide an accurate 10MHz
>I have a Rubidium standalone, which I fear I may need because none of my
>references are modern.
>
>
>You may see people flogging off some professional GPS frequency
>standards. Some may be real bargains if there is a 'fix', other may
>become simply a source of a reasonable 10MHz OCXO Caveat emptor!
>
>
>Happy Binary Birthday GPS!
>

[kinsell]

3. also depends on what firmware is loaded


The popular GPS25 engine, used in the really old FR's, had a firmware
update released in 2000, just after the start of the second epoch.

The GPS15, a newer, drop-in replacement for the 25, had numerous
firmware updates released through 2009 I believe. It's possible to rig
the firmware to provide 1024 weeks of trouble-free operation from any
given arbitrary date. Maybe they did that, maybe not. It's called
"setting a pivot point" by the manufacturers.

Both the '25 and the '15 have data sheets when say the internal
batteries provide "up to 21 days" of keeping the RTC data alive. You
can't really blame Garmin for the problems in the flight recorders, it
was a poor choice of components on the part of Cambridge and others to
use these things in FR's that likely sit six months without charging in
the off season.

-Dave





On 2/24/19 8:33 AM, Tim Newport-Peace wrote:
> Known issue, see http://tinyurl.com/y56n8odz
>
> If it will effect your Flight Recorder depends on:
>
> 1. The ago of the GPS Engine in your recorder.
> 2. The condition of the RTC battery in the GPS Engine.
>
> After 6th April 2019, you can check the date by downloading a flight made
> after 6th April 2019 and opening the .IGC file with a text editor, such as
> Wordpad. Within the first few records you will find a line beginning
> “HFDTE” followed by a date, if this is the date of the flight, then you
> are fine, otherwise you have a problem. Talk to your dealer.
>
> At 14:22 24 February 2019, Soartech wrote:
>> Just saw this:
>>
>> Subject: [UKMicrowaves] GPS Frequency standards.. Week Zero alert.
>> Date: Thu, 7 Feb 2019 18:39:05 -0000
>> From: Mark GM4ISM
>>
>>
>>
>> For those of us reliant on GPS based frequency standards and location
>> systems, there is an upcoming event that may upset some GPS engines.
>>
>> GPS week numbers only go up to 1024 and we hit another 'week zero' event
>> on 6th April this year.
>>
>> This can and does cause some older GPS engines to become rather upset.
>> Some completely loose lock, some may still produce 1 PPS etc but output
>> the wrong date and time
>> Many of these recover at week 1 but that is not guaranteed.
>>
>> Some testing has been done by a colleague on a number of GPS based
>> systems using a locally generated GPS signal set that simulates the week
>> zero signals.
>> A number of older GPS engines have failed this test and the frequency
>> standards associated with them have been shown to go into holdover and
>> start to drift....
>> Amongst the ones likely to fall over are the Rockwell chipset widely
>> used by amateurs. The exact model with 10KHz (Jupiter) out has not been
>> confirmed but pretty much all of the related models, used in a number of
>> GPS disciplined oscillators, fell over.
>> The Jupiter in my old RUH system already needs a poke of serial data at
>> start-up, I believe to correct a previous timestamp rollover. I guess it
>> may need a different one soon.
>> I am aware that if all else fails, UBlox GPS engines have been
>> successfully used in the RUH design standard in place of the Jupiter, as
>> some Ublox engines can be programmed to output the required 10KHz
>> instead of 1PPS
>> All (slightly older ) UBlox modules that have been tested were
>> unaffected so it is likely that newer ones will be OK too,
>>
>> Some older Rapco GPS standards fail the Week Zero test which makes them
>> think they are the best part of twenty years younger. Their recovery
>> into week 1 is not certain.
>>
>> I am aware that at least one model of these has an internal firmware
>> week counter which will rollover in July if I recall, further
>> complicating matters
>> I also have one of these and its useful life is now in question.
>>
>> The Trimble Palisades out there are an unknown quantity.
>> I will try to get one tested. I use one of these with a VE2ZAZ system
>> and so does GB3CSB
>>
>>
>>
>> Recovery in week 1 has not been tested in my world, a full week in
>> holdover is not acceptable so units are being replaced.
>>
>>
>> So the upshot is that for the duration of week 0, your GPS freq
>> standard, if based round an older GPS engine, may fail to lock and
>> provide an accurate 10MHz
>> I have a Rubidium standalone, which I fear I may need because none of my
>> references are modern.
>>
>>
>> You may see people flogging off some professional GPS frequency
>> standards. Some may be real bargains if there is a 'fix', other may
>> become simply a source of a reasonable 10MHz OCXO Caveat emptor!
>>
>>
>> Happy Binary Birthday GPS!
>>
>

[Tim Newport-Peace[_4_]]

Interesting. I have a Garmin Specification that says the backup power is
"up to 6 months". However, whatever it is, it will reduce with ago.

As for the choice of components, it was what was available at the time,
which was a long time ago.

At 17:36 24 February 2019, kinsell wrote:
>3. also depends on what firmware is loaded
>
>
>The popular GPS25 engine, used in the really old FR's, had a firmware
>update released in 2000, just after the start of the second epoch.
>
>The GPS15, a newer, drop-in replacement for the 25, had numerous
>firmware updates released through 2009 I believe. It's possible to rig
>the firmware to provide 1024 weeks of trouble-free operation from any
>given arbitrary date. Maybe they did that, maybe not. It's called
>"setting a pivot point" by the manufacturers.
>
>Both the '25 and the '15 have data sheets when say the internal
>batteries provide "up to 21 days" of keeping the RTC data alive. You
>can't really blame Garmin for the problems in the flight recorders, it
>was a poor choice of components on the part of Cambridge and others to
>use these things in FR's that likely sit six months without charging in
>the off season.
>
>-Dave
>
>
>
>
>
>On 2/24/19 8:33 AM, Tim Newport-Peace wrote:
>> Known issue, see http://tinyurl.com/y56n8odz
>>
>> If it will effect your Flight Recorder depends on:
>>
>> 1. The ago of the GPS Engine in your recorder.
>> 2. The condition of the RTC battery in the GPS Engine.
>>
>> After 6th April 2019, you can check the date by downloading a flight
made
>> after 6th April 2019 and opening the .IGC file with a text editor, such
>as
>> Wordpad. Within the first few records you will find a line beginning
>> “HFDTE” followed by a date, if this is the date of the
>flight, then you
>> are fine, otherwise you have a problem. Talk to your dealer.
>>

[kinsell]

I'm not finding the 21 day spec for the '25 in a quick search, but here
it is on page 3 for the '15:

https://static.garmincdn.com/pumac/GPS15xH_15xL_TechnicalSpecifications.pdf

There are multiple variants for both the '25 and '15, perhaps that is
confusing the issue.

Certainly the selection of suitable engines was limited back in those
days, but the FR vendors could have done a better job of documenting the
issue, or even providing additional batteries in their units to mitigate
the problem. My ancient backpacker gps still has the correct date
today, probably because it has AA batteries installed at all times
except when changing them.

Dave




On 2/24/19 11:05 AM, Tim Newport-Peace wrote:
> Interesting. I have a Garmin Specification that says the backup power is
> "up to 6 months". However, whatever it is, it will reduce with ago.
>
> As for the choice of components, it was what was available at the time,
> which was a long time ago.
>
> At 17:36 24 February 2019, kinsell wrote:
>> 3. also depends on what firmware is loaded
>>
>>
>> The popular GPS25 engine, used in the really old FR's, had a firmware
>> update released in 2000, just after the start of the second epoch.
>>
>> The GPS15, a newer, drop-in replacement for the 25, had numerous
>> firmware updates released through 2009 I believe. It's possible to rig
>> the firmware to provide 1024 weeks of trouble-free operation from any
>> given arbitrary date. Maybe they did that, maybe not. It's called
>> "setting a pivot point" by the manufacturers.
>>
>> Both the '25 and the '15 have data sheets when say the internal
>> batteries provide "up to 21 days" of keeping the RTC data alive. You
>> can't really blame Garmin for the problems in the flight recorders, it
>> was a poor choice of components on the part of Cambridge and others to
>> use these things in FR's that likely sit six months without charging in
>> the off season.
>>
>> -Dave
>>
>>
>>
>>
>>
>> On 2/24/19 8:33 AM, Tim Newport-Peace wrote:
>>> Known issue, see http://tinyurl.com/y56n8odz
>>>
>>> If it will effect your Flight Recorder depends on:
>>>
>>> 1. The ago of the GPS Engine in your recorder.
>>> 2. The condition of the RTC battery in the GPS Engine.
>>>
>>> After 6th April 2019, you can check the date by downloading a flight
> made
>>> after 6th April 2019 and opening the .IGC file with a text editor, such
>> as
>>> Wordpad. Within the first few records you will find a line beginning
>>> “HFDTE” followed by a date, if this is the date of the
>> flight, then you
>>> are fine, otherwise you have a problem. Talk to your dealer.
>>>
>
>

[kinsell]

Note to O.P. -- this subject was beat to death about a month ago on this
very forum, so if you're looking for more discussion, it's available.

General consensus, not surprisingly, was that newer devices should be
fine, really old devices may show some failures. Old devices have their
week counter roll over in a little less than 20 years, newer devices
should roll over in about 150 years, if they're taking advantage of the
three additional bits in the week counter.


On 2/24/19 7:22 AM, Soartech wrote:
> Just saw this:
>
> Subject: [UKMicrowaves] GPS Frequency standards.. Week Zero alert.
> Date: Thu, 7 Feb 2019 18:39:05 -0000
> From: Mark GM4ISM
>
>
>
> For those of us reliant on GPS based frequency standards and location
> systems, there is an upcoming event that may upset some GPS engines.
>
> GPS week numbers only go up to 1024 and we hit another 'week zero' event
> on 6th April this year.
>
> This can and does cause some older GPS engines to become rather upset.
> Some completely loose lock, some may still produce 1 PPS etc but output
> the wrong date and time
> Many of these recover at week 1 but that is not guaranteed.
>
> Some testing has been done by a colleague on a number of GPS based
> systems using a locally generated GPS signal set that simulates the week
> zero signals.
> A number of older GPS engines have failed this test and the frequency
> standards associated with them have been shown to go into holdover and
> start to drift....
> Amongst the ones likely to fall over are the Rockwell chipset widely
> used by amateurs. The exact model with 10KHz (Jupiter) out has not been
> confirmed but pretty much all of the related models, used in a number of
> GPS disciplined oscillators, fell over.
> The Jupiter in my old RUH system already needs a poke of serial data at
> start-up, I believe to correct a previous timestamp rollover. I guess it
> may need a different one soon.
> I am aware that if all else fails, UBlox GPS engines have been
> successfully used in the RUH design standard in place of the Jupiter, as
> some Ublox engines can be programmed to output the required 10KHz
> instead of 1PPS
> All (slightly older ) UBlox modules that have been tested were
> unaffected so it is likely that newer ones will be OK too,
>
> Some older Rapco GPS standards fail the Week Zero test which makes them
> think they are the best part of twenty years younger. Their recovery
> into week 1 is not certain.
>
> I am aware that at least one model of these has an internal firmware
> week counter which will rollover in July if I recall, further
> complicating matters
> I also have one of these and its useful life is now in question.
>
> The Trimble Palisades out there are an unknown quantity.
> I will try to get one tested. I use one of these with a VE2ZAZ system
> and so does GB3CSB
>
>
>
> Recovery in week 1 has not been tested in my world, a full week in
> holdover is not acceptable so units are being replaced.
>
>
> So the upshot is that for the duration of week 0, your GPS freq
> standard, if based round an older GPS engine, may fail to lock and
> provide an accurate 10MHz
> I have a Rubidium standalone, which I fear I may need because none of my
> references are modern.
>
>
> You may see people flogging off some professional GPS frequency
> standards. Some may be real bargains if there is a 'fix', other may
> become simply a source of a reasonable 10MHz OCXO Caveat emptor!
>
>
> Happy Binary Birthday GPS!
>