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

[NivagSwerdna]

Personally, I've unsoldered the leds and connect new ones on the frontplate:

Did you need 2 wires for each or do they have a common (ground?) on one side?
Thanks in advance

[f1rmb]

Personally, I've unsoldered the leds and connect new ones on the frontplate:

Did you need 2 wires for each or do they have a common (ground?) on one side?
Thanks in advance

Hi didn't even checked, just soldered 2 wires for each (they are dual LEDs).


Cheers.
---
Daniel

[guido]

in my case i'm not using the LEDs on the UCCM. One is power supply, one is showing 12V to XO (it is switchable) and the other two will be controlled by the pic. Current plan; one to indicate that the output is on and one in case of an alarm. Tbd.

[davebb]

That look good ,good idea with the LEDs to test what one was what,
what op-amps did you use for your output board,
I am fitting a usb interface on mine,
Dave

[SHF]

That look good ,good idea with the LEDs to test what one was what,
what op-amps did you use for your output board,
I am fitting a usb interface on mine,
Dave

the op-amps are 4x AD811 buffer output amplifier
-->usb interface what a circuit ??
Dieter

[davebb]

Hi it was just a cheep £1 ftdi board from China
That has mini USB and I got a mini usb to std USB B panel mount lead I got 1for my Trimble as well
Dave

[bingo600]

Hi Daniel
Yes please that would be brill,i wish I could do that,
Thanks Dave 2E0DMB

Here it is. Please tell me if it works, this way I can send the fix to the original author.


Cheers.
---
Daniel

Re:
https://www.eevblog.com/forum/projects/a-look-at-my-symmetricom-gpsdo-(ocxo-furuno-receiver)/msg849732/#msg849732

Any change of getting the sourcecode , or at least a description of the differences against the below source 

Afficheur-GPS-V2.22-Source
http://www.f4ctz.fr/?page_id=692&aid=1282&sa=1

I'm using AVR not PIC

/Bingo

[NivagSwerdna]

FWIW... This is what I'm going to use... 

http://www.ebay.co.uk/itm/221831832114  2.4" Touch Screen

http://www.ebay.co.uk/itm/291716131140   Arduino Mega2560

The Mega has 4 UARTs, so I can do both sets of serial (SCPI in/out and GPS out) and provide USB out to a PC when required.

I'll let you know how it goes

[davebb]

Hi that should be good,
please let us know
Dave

[f1rmb]

Hi Daniel
Yes please that would be brill,i wish I could do that,
Thanks Dave 2E0DMB

Here it is. Please tell me if it works, this way I can send the fix to the original author.


Cheers.
---
Daniel

Re:
https://www.eevblog.com/forum/projects/a-look-at-my-symmetricom-gpsdo-(ocxo-furuno-receiver)/msg849732/#msg849732

Any change of getting the sourcecode , or at least a description of the differences against the below source 

Afficheur-GPS-V2.22-Source
http://www.f4ctz.fr/?page_id=692&aid=1282&sa=1

I'm using AVR not PIC

/Bingo

I sent the patch this week for the furuno support to F4CTZ, I think he will made it available soon (full source code or patch only, I don't know).

Cheers.
---
Daniel

[Bryan]

All:

Pin 3 is referred as the GPX TX from other photos in the thread. Which is the RX pin in my edited photo. Is it 4?

[NivagSwerdna]

I think your numbering might be off.

I read it as

1 2
3 4
5 6
7 8
9 X

or the other way up (in your pic)

RD and TX are on the same row

[Bryan]

Thanks for the help, yes the numbering is wrong . So in short my pin 4 in the picture is the RX(RD) pin.

[gm8bjf]

Hi have you seen from a post on here there is a UK seller selling these for the same price, don't know if they are sent in the UK?
Dave

Hi Dave,
Just seen your post. The supplier I was referring to is here:

http://www.ebay.co.uk/itm/Used-SYMMETRICOM-UCCM-GPS-10MHz-Frequency-Time-Receiver-OCXO-/281950388728?hash=item41a58d81f8:g:Er8AAOSwv9hW

They still seem to have some. There are three suppliers here in UK but I suspect they are aliases of the same shop. All are based in Salford. I have had three units from them and all have required various degrees of repair and cleaning. They are posted from the UK. Latest fault was one of the TI buck converter boards failing while in operation. The units seem to have originated from the far east and have have coordinates around Tokyo and Okoyama in Japan stored in them, same as the ones direct from China. The UK based supplies are actually cheaper than the Chinese ones and you don't have to wait 2-3 weeks!
I have found the supplier easy to deal with. When one of my units was quite badly damaged they sent a replacement.

Brian GM8BJF

[davebb]

Hi Brian
Thanks for the info, it is good to know that they sent you a
Replacement unit, did they let you keep the old unit?
Thanks Dave 2E0DMB

[Nuno_pt]

Would it be better to buy this Symmetricom or the Trimble 65256 GPS OCXO from the same seller?

The Symmetricon is faster since it's available in the UK, the Trimble must come from the other side, the price it's about the same.

Any ideas?

[davebb]

The only thing about the Symmetricom is that when you do a power off on re-connect it will take 2hours to do a survey ,but the trimble remembers and saves its settings so when the trimble gets lock that's it going after mins not hours,
Dave

[Nuno_pt]

davebb,

The GPSDO will be to put on a shelf over the bench, to plug the Frequency counter, and other stuff, so I don't see me to unplug it very often.
But I can always add some switch to change from +5VDC 3A, to battery pack to move it.

[gm8bjf]

Hi Brian
Thanks for the info, it is good to know that they sent you a
Replacement unit, did they let you keep the old unit?
Thanks Dave 2E0DMB

Hi Dave,

Yes they did, but its Buck inverter has now gone to the great scrapyard in the sky for no obvious reason! From messages on Ebay I have the impression they are Chinese sellers in the UK.

73s

Brian.

[Nuno_pt]

Well, thinking more about this and going trough the parts recycle bin, I've found some GPS boards Navman Jupiter-T TU30-D405-005, WITH 10kHz and 1PPS outputs, so the only thing that is needed is one OCXO like the MV89 from Morion, and one circuit like the one from G3RUH < http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm >.

[guido]

The only thing about the Symmetricom is that when you do a power off on re-connect it will take 2hours to do a survey ,but the trimble remembers and saves its settings so when the trimble gets lock that's it going after mins not hours,
Dave

I have the feeling it is sometimes quicker. But sometimes not so. I'm poking my position into the unit, maybe if i use a fixed GPS antenna (on the to-do list) that would really work. According to another manual (58503B unit) poking position and time/date should help to speed things up. I´ve tried it,  but did not find an improvement. But maybe that´s because the gps antenna is not a fixed one. If more people could try 

Unfortunately i won´t be able to easily load date/time with my acient pic solution. Could add an RTC chip but that also requires setting (and writing software to do so). Current status is that i have multiple reponse strings on the display and switching on a red LED in case the pll status is not saying PLL stabilized. The info is also on the display obviously, but a red LED will be much more visible.

When i get more time, i´ll continue with the button control for the output and it´s status LED and then some costmetics. It´s a slow process, i program in assembly (and i like it) 

[TheSteve]

For those in the US who are interested in one of the Symmetricom GPSDO's there is a seller on ebay who has a few for 43.99 shipped. To find them you can search for "SYMMETRICOM UCCM", I have no relation to seller, but if they work it is a pretty decent price.

[Bryan]

For those in the US who are interested in one of the Symmetricom GPSDO's there is a seller on ebay who has a few for 43.99 shipped. To find them you can search for "SYMMETRICOM UCCM", I have no relation to seller, but if they work it is a pretty decent price.

Searching with "SYMMETRICOM UCCM" on EBay doesn't bring anything up other than the seller from China. Do you have a EBAY listing number.

Cheers

[NivagSwerdna]

I traced out the LEDs so that I could work out what I need on the front-panel.

I'm still not exactly sure what they all do but it seems that ACT (DS3 Green) comes from the FPGA (as does the Green side of DS4), all other LEDs are controlled by the H8S.

(I must upgrade to Dave CAD at some point)

[TheSteve]

For those in the US who are interested in one of the Symmetricom GPSDO's there is a seller on ebay who has a few for 43.99 shipped. To find them you can search for "SYMMETRICOM UCCM", I have no relation to seller, but if they work it is a pretty decent price.

Searching with "SYMMETRICOM UCCM" on EBay doesn't bring anything up other than the seller from China. Do you have a EBAY listing number.

Cheers

Try eBay # 322024166858