Author Topic: Symmetricom NTS-200 Time Server (Read 18679 times)

BloodyCactus · « **on:** February 03, 2016, 12:58:12 am »

So, I got an NTS-200 off ebay for an absolute score, in unworking condition. Seller said it would not find satellites and nothing worked. ok.

So, it finds satellites just fine (it can take 10 minutes to acquire, thats not unusual, maybe seller thought it would be instant.. shrug)..

so I finally got into the remote system and reset the passwords, now the last problem its like dealing with racal dana all over again... dead buttons! Under the rubber button, there was supposed to be some conductive material, but its all gummed up and nasty. I need
to figure what I can do to replace it. :/ anyone got any ideas. At worst I could try and jury rig a tactile button replacement and fit the black rubber pad back over top of it.

Here is the dead input board;

uncle_bob · « **Reply #1 on:** February 03, 2016, 01:48:03 am »

Hi

When you get it up and running, I suspect you will find that the GPS has the decade rollover bug and needs to be replaced. I would double check that before you go much further.

Bob

BloodyCactus · « **Reply #2 on:** February 03, 2016, 02:04:47 am »

Ive had it working fine, just the front buttons dont work. had it tracking 6+ sats and feeding time to several devices on my network without issue.

whats the decade rollover bug? pulling the version I get "Network Interface 182-9004v8.2 (c) 1998 - 2003 Symmetricom Inc." so its 8.2 (there is/was a 8.4 but nobody seems to have it).

uncle_bob · « **Reply #3 on:** February 03, 2016, 02:22:01 am »

Hi

The wonderful people who defined the standard GPS messages did not consider gear that would be running for a long time. The assumption was that anything past a few years was about all that needed to be covered. They came up with a coding system that rolls over every 1024 weeks. A lot of gear only knows that it was built in some year and it must not be before than year. Once you get past 1024 weeks past that, it gets confused. Symmetricom had a problem with a bunch of the NTS boxes fairly recently. I have no idea if the 200 was in that group or not.

Bob

BloodyCactus · « **Reply #4 on:** February 03, 2016, 02:25:33 am »

aah ok, so its an uptime bug. I was thinking it was like a y2k bug. I dont expect I'd have such serious 1024 WEEK uptimes, thats like 18+ years...

as for time, its fine on this end

edpalmer42 · « **Reply #5 on:** February 03, 2016, 03:11:38 am »

I don't know about the 'gummy' part of your problem, but I recently fixed some bad conductive spots by slicing off the old ones and gluing on ones that I cut off of a surplus remote control. It works fine, just be sure that after the replacement the spots aren't going to short out the contacts.

If you want to get official, I've seen actual repair kits for this type of buttons. I don't know of a source, but Google knows all!

BloodyCactus · « **Reply #6 on:** February 03, 2016, 03:32:33 am »

thanks, thats a neat hack glueing old remote buttons on. I did a continuty test on the button pad and whatever is on there is not conductive.

edpalmer42 · « **Reply #7 on:** February 03, 2016, 03:59:54 am »

Quote from: BloodyCactus on February 03, 2016, 03:32:33 am

thanks, thats a neat hack glueing old remote buttons on. I did a continuty test on the button pad and whatever is on there is not conductive.

Check carefully! We're not talking 0 ohms, more like 100s of ohms. Or maybe, the lack of continuity is the problem. The buttons I had to replace were like that.

Mr Smiley · « **Reply #8 on:** February 03, 2016, 04:44:58 am »

You can get repair kits like this

http://www.ebay.co.uk/itm/Keypad-Button-Repair-Kit-for-TV-Remote-Controls-Rubber-Buttons-Cordless-Phones-/252160081827?hash=item3ab5e97fa3:g:ueQAAOSwQoFWPOuY

edpalmer42 · « **Reply #9 on:** February 03, 2016, 04:52:06 am »

Good link! A little more searching found this one:

http://www.ebay.com/itm/262265110349

Choose your size and quantity.

These are much cheaper than the one I saw!

TheSteve · « **Reply #10 on:** February 03, 2016, 04:58:07 am »

I have also repaired a keypad before using parts from an old calculator. If you have something on hand to sacrifice give it a shot, if not get a repair kit.

Mr Smiley · « **Reply #11 on:** February 03, 2016, 05:12:52 am »

I repaired my next door neighbours sky remote a few years ago, as in your case, the conductive rubber had perished on his most used button. A quick fix was some silver foil ( Aluminium cooking foil ) and a paper punch. punched out a small round piece and glued it onto the back of the button, still going strong

uncle_bob · « **Reply #12 on:** February 03, 2016, 05:54:43 pm »

Quote from: BloodyCactus on February 03, 2016, 02:25:33 am

aah ok, so its an uptime bug. I was thinking it was like a y2k bug. I dont expect I'd have such serious 1024 WEEK uptimes, thats like 18+ years...

as for time, its fine on this end

Hi

That looks ok.

Actually the problem manifests its self like a Y2K bug in most systems. The date magically leaps back 1024 weeks when the "expiration date" on the GPS module firmware hits. The modules in some of these gizmos have firmware that dates to the mid/late 90's even if the device firmware was done later. It's well worth checking (as you have done). Yes you could write firmware that was a bit smarter, unfortunately a lot of people did not. You can also do a better job with the GPS data. That change will be implemented with the launch of some new sat's "real soon now" (first it was 2005 then 20010 then 2015 then 2018 ...).

Bob

BloodyCactus · « **Reply #13 on:** February 09, 2016, 01:59:05 am »

Got one of those button replacement kits from ebay for $2 or something. Worked like a charm. Now my goal is to get 100ft of LMR-240 with a male BNC on one and and male TNC on the other so I can run it to the roof. I should probably run some string to make sure 100ft is sufficient. I think it should be.

Right now its serving time as a startum 1 ntp server to everything on the network. very cool!

uncle_bob · « **Reply #14 on:** February 09, 2016, 02:38:40 am »

Quote from: BloodyCactus on February 09, 2016, 01:59:05 am

Got one of those button replacement kits from ebay for $2 or something. Worked like a charm. Now my goal is to get 100ft of LMR-240 with a male BNC on one and and male TNC on the other so I can run it to the roof. I should probably run some string to make sure 100ft is sufficient. I think it should be.

Right now its serving time as a startum 1 ntp server to everything on the network. very cool!

Hi

RG-6 quad shield will save you a ton of money over the LMR. You can likely get RG-11 cheaper as well. For a GPS receive antenna it's more about loss than match. Neither end (source or load) may be well terminated. If it's outdoors, make sure you get the outdoor rated stuff. (still cheaper than LMR).

Bob

MonarkeIV · « **Reply #15 on:** March 03, 2019, 01:13:29 pm »

I know this topic is 120 days past, but I found a notice from Microsemi that apparently it's the Symmetricom TS2100 which has the Decade Rollover Bug.

http://www.heoldesign.com/IMG/pdf/heol-tech_note_119_en_r02.pdf

In case the link becomes invalid, I'll also attached the notice file.

uncle_bob · « **Reply #16 on:** March 03, 2019, 01:51:43 pm »

Hi

It's a pretty good bet that *any* GPS based gear you buy surplus will have a 1024 week related issue. The problem has been pretty well known for 20 years now. Oddly enough, the only parts I've seen with really good fixes for the issue have come out in the last 5 years or so. Since those are raw GPS module parts, it will take a while for them to get into products. It will then take a while for those products to get into the surplus market.

Bob

MonarkeIV · « **Reply #17 on:** March 03, 2019, 04:01:13 pm »

Quote from: uncle_bob on March 03, 2019, 01:51:43 pm

Hi

It's a pretty good bet that *any* GPS based gear you buy surplus will have a 1024 week related issue. The problem has been pretty well known for 20 years now.

Bob

If this is the case then used GPS units from Spectracom and Symmetricom should be priced much lower on eBay (thinking door stop) than they currently are, considering firmware updates may not be available from Microsemi and Orolia...

uncle_bob · « **Reply #18 on:** March 03, 2019, 04:22:06 pm »

Hi

Most of these outfits support firmware upgrades over a limited period of time. If you get those sort of fixes for a 5 year period after you purchased the device directly from them, you are doing pretty well. Outfits like Cisco would like you to sign up (and pay for) updates on most of their gear. Survey GPS gear is in the same bucket. Pay them a couple thousand dollars and you can get your four year old device updated to latest revision. Pay them a whole lot more and you can get it upgraded to the current feature set. The days of "free updates forever and ever" are long gone. (If such a thing ever was the case in the past ....).

Bob

edpalmer42 · « **Reply #19 on:** March 03, 2019, 05:39:09 pm »

Another thing that helps give older GPS units a helping hand is that the NTP software running on Windows or Linux can be patched to compensate for a rollover bug. The Trimble Thunderbolt went through this a couple of years ago. Once the bug surfaced, it took some months for the fix to work its way through to the publicly released software, but it did happen.

Ed

uncle_bob · « **Reply #20 on:** March 03, 2019, 05:43:23 pm »

Hi

One gotcha with an external "fix" for a rollover shows up when a leap second comes along. The firmware *expects* to apply it at the end of December or end of June based on the standards that apply. The problem is, the device no longer is correct when it looks at the date. What it thinks is June is no longer June. In some cases things work ok. In other cases ...errr .... not so much.

Bob

edpalmer42 · « **Reply #21 on:** March 03, 2019, 06:20:33 pm »

Quote from: uncle_bob on March 03, 2019, 05:43:23 pm

Hi

One gotcha with an external "fix" for a rollover shows up when a leap second comes along. The firmware *expects* to apply it at the end of December or end of June based on the standards that apply. The problem is, the device no longer is correct when it looks at the date. What it thinks is June is no longer June. In some cases things work ok. In other cases ...errr .... not so much.

If that happens, it can be patched. No, it isn't an ideal solution, and it likely isn't possible for a closed source device like a Symmetricom server, but it's practical for some situations.

Ed

fira4 · « **Reply #22 on:** April 01, 2019, 07:18:14 am »

Quote from: MonarkeIV on March 03, 2019, 01:13:29 pm

I know this topic is 120 days past, but I found a notice from Microsemi that apparently it's the Symmetricom TS2100 which has the Decade Rollover Bug.

http://www.heoldesign.com/IMG/pdf/heol-tech_note_119_en_r02.pdf

In case the link becomes invalid, I'll also attached the notice file.

i have 2 unit NTS-200 up and running till now, does this type impacted with gps rollover bug?

b0bd · « **Reply #23 on:** December 30, 2019, 07:03:08 pm »

fira4 or anyone else,

anyone been affected by the GPS rollover bug, in that their NTS-200 now thinks its April of 2000. Took me a while to realize why my local clocks were suddenly an hour off. A couple of other servers that are available on the internet have the same issue.

workaround for now is unplug the antenna and configure ntp servers.

fira4 · « **Reply #24 on:** January 02, 2020, 06:11:52 am »

Quote from: b0bd on December 30, 2019, 07:03:08 pm

fira4 or anyone else,

anyone been affected by the GPS rollover bug, in that their NTS-200 now thinks its April of 2000. Took me a while to realize why my local clocks were suddenly an hour off. A couple of other servers that are available on the internet have the same issue.

workaround for now is unplug the antenna and configure ntp servers.

Yep, its reset to 2000.


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Author Topic: Symmetricom NTS-200 Time Server (Read 18679 times)

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