A look at my Symmetricom GPSDO / 10MHz reference (OCXO + Furuno receiver)

[grumpydoc]

This is U26, not sure what it is:

My guess would be a single gate and given the "08" marking probably a single AND gate.

[PA0PBZ]

My guess would be a single gate and given the "08" marking probably a single AND gate.

Yes, that would be a good guess. I could of course take it from the pcb, power it up and measure what it does but it is too small for my old eyes 

[grumpydoc]

Yes, that would be a good guess. I could of course take it from the pcb, power it up and measure what it does but it is too small for my old eyes 

With you on that one - I can barely do anything electronic without a stout magnifying glass

[Macbeth]

FWIW mine is marked T08B (or T088) and has 3 dots all in line from bottom left.

[PA0PBZ]

FWIW mine is marked T08B (or T088) and has 3 dots all in line from bottom left.

Interesting, T08 SOT-753 is a  74HCT1G08GV, AND gate indeed.

[GI1CET]

Dave, 2E0dmb

No its not, I just didn't play with the lighting when taking the photo ;-)

Jim, GI1CET

[GI1CET]

All

Thanks for that incredibly useful info  i will source some 74HCT1G08GV and get the iron hot, many thanks

will report results here but it may be delayed as I am back and forth to the Mainland non stop for the next few weeks so not much time to play ;-)

Jim, GI1CET

[pmcouto]

Hi,

My board is missing U9…

Looking at the picture here https://www.eevblog.com/forum/projects/a-look-at-my-symmetricom-gpsdo-(ocxo-furuno-receiver)/msg924815/#msg924815
the marking on that little 5 pin SMD IC seems to be 10CB, 10C8 or 1DCB.

Could you please take a look at your boards and let me know the correct SMD marking on this IC?

[PA0PBZ]

the marking on that little 5 pin SMD IC seems to be 10CB, 10C8 or 1DCB.

I sent that board back but I had another picture which I think shows 19CB. The one on the board I have here says AAAV.

[Nuno_pt]

pmcouto, in the end of the day I will see my board what is there.

[Bryan]

Whereabouts on the board is U9 and I will check mine if it helps. Mine arrived complete and working.

[kutte]

if you want some monitoring software running under windows, here it is:
http://www.romahn.info/symmetricom/Z38SY.ZIP
I've patched Ulrich Bangert's famous Z38XX to at least partially work with our Symmetricom UCCM-P.
For use first set the right "parameters" i.e. your com-port and hit ok.
Try the various functions under the "view" tab.
Kutte

[Bryan]

Slick, will have to give it a try. Miss the Lady Heather program.

[SHF]

if you want some monitoring software running under windows, here it is:
http://www.romahn.info/symmetricom/Z38SY.ZIP
I've patched Ulrich Bangert's famous Z38XX to at least partially work with our Symmetricom UCCM-P.
For use first set the right "parameters" i.e. your com-port and hit ok.
Try the various functions under the "view" tab.
Kutte

Hallo Kutte super Programm  , vielen Dank hier für das posten !!!
Gruß Dieter

[Macbeth]

I sent that board back but I had another picture which I think shows 19CB. The one on the board I have here says AAAV.

Can confirm - 19CB on mine.

[Macbeth]

if you want some monitoring software running under windows, here it is:
http://www.romahn.info/symmetricom/Z38SY.ZIP
I've patched Ulrich Bangert's famous Z38XX to at least partially work with our Symmetricom UCCM-P.
For use first set the right "parameters" i.e. your com-port and hit ok.
Try the various functions under the "view" tab.
Kutte

This is great! I assume by patched you used a hex editor to fix some strings vs compiling unobtanium source code?

I had just started writing something similar in C#.NET too...

Unfortunately the main PPS TI & EFC window doesn't update, and the Time Stability and "Nixie" Clock are greyed out too Looking at the debug log the EFC values are being queried and coming back with sensible values ok. Is there an obvious reason why these don't work other than the great difficulty in reverse engineering the original?

[Macbeth]

You can also adjust the RS232 header to a different baud rate by using one of the two and select your baud rate.

SYSTem:COMMunication:SERial1:BAUD 9600|19200|38400|57600
or
SYSTem:COMMunication:SERial2:BAUD 9600|19200|38400|57600

I think it's the second one.

It is the SER2 that is the RS232 header.

Just a note your settings won't stick after a reboot, although I think the following may store the setting, just never tried it

SYSTem:COMMunication:SERial1:PRESet
SYSTem:COMMunication:SERial2:PRESet

Nope. These restore to factory default 57600,8,N,1

How do I know this? Because for some reason I get lots of line noise at 57600 baud (reminds me of my 1200 baud dial up modem days!). I use SYST:COMM:SER2:BAUD 19200 and all is ok but of course I have to reconnect after issuing that command.

This is possibly a fault of my cheap-ass CH340 USB/RS232 adapter.

[kutte]

This is great! I assume by patched you used a hex editor to fix some strings vs compiling unobtanium source code?

I had just started writing something similar in C#.NET too...

Unfortunately the main PPS TI & EFC window doesn't update, and the Time Stability and "Nixie" Clock are greyed out too Looking at the debug log the EFC values are being queried and coming back with sensible values ok. Is there an obvious reason why these don't work other than the great difficulty in reverse engineering the original?

hi Macbeth,
I've made similar patches for my Lucent KS-24361 GPSDO and that worked in all aspects you are missing now. But the Symmetricom UCCM's command set differs in too many aspects from the original Z38xx command sets, so I could not put to work more than what is available. And yes, you are right, the sources of Ulrich's Z38xx are unobtainium. If anyone wants more functionality he (she) is free to do more reverse engineering and should tell us about any success.
Kutte

[kutte]

Stability and "Nixie" Clock are greyed out too Looking at the debug log the EFC values are being queried and coming back with sensible values ok. Is there an obvious reason why these don't work other than the great difficulty in reverse engineering the original?

I am missing that information too. The reason seems to be, that the Symmetricom does not deliver the appropriate timing data and additionally always appends an unwanted "Command Complete" string to any command given.

I did also not succeed to put time/date date into the Symmetricom to speed up satellite aquisition.
GPS:INITial:DATE 2016,1,29   // does not work (legal syntax but no effect)
GPS:INITial:TIME 23:59:01   // does not work (legal syntax but no effect)
GPS:INITial:POSition N,+52,+etc,E,+13,+etc // works ok
Kutte

[deepskyridge]

I am thinking of picking up one of these, do you guys have any documentation ?

I don't want to read all 20 pages of this thread.

Thanks
Gary

[ghulands]

I am thinking of picking up one of these, do you guys have any documentation ?

I don't want to read all 20 pages of this thread.

Thanks
Gary

Click the All next to the page numbers, then it's only a single page! 

[Macbeth]

I am thinking of picking up one of these, do you guys have any documentation ?

I don't want to read all 20 pages of this thread.

Thanks
Gary

Maybe, unlike all of us, you can find the official manuals and datasheets? - I believe Penguin published a compendium but I haven't found much more than a book cover teaser myself...



I've rifled through dusty old bookshops high and low, but to no avail... I did find "Fly Fishing by J.R. Hartley" though 

[NivagSwerdna]

I found everything I needed, including links to various bits of documentation in the thread.

[Nuno_pt]

+1 for that.

But it requires time to read. 

[NivagSwerdna]

I'm a bit out of my depth here... but... after fiddling with some R values I seem to have a good output from the LT6551 (wow it was small).

Firstly I tried driving a 50R but this seemed to be a bit much for the output of the UCCM-P so I upped this by adding a 67R I had lying around giving around 120R and now I am seeing sufficient output on the LT6551 side (around 3V pp) after fixed x2 gain....

For bias I used a 5k4 and 1k5 I had lying around.

I wish I had made a PCB... now to wire up some outputs and see if it can drive the SDG1025 and Racal-Dana 1999 Counter...

I have 4 outputs.