[time-nuts] Tymserve 2100 - Adding a LPRO Rb

Jason Rabel jason at extremeoverclocking.com
Tue Jan 2 20:26:37 EST 2007


First, good luck on this project, I really hope you can get it working!

Interesting that you were able to plug in a GPS and get it to instantly
work. Now you made me curious if I could do the same for my NTS-100 IRIG. I
was able to compare to someone elses NTS-100 GPS, and it appeared to have an
ACE II GPS also. One difference was my IRIG had an extra chip onboard that
his didn't, there was a sticker with a version number, but also handwritten
"NASA36" which makes me think it was a special extra chip to either read or
output the NASA36 time code. But anyhow back to the GPS... I'm going to get
me one and see what happens, I'll be sure to let everyone know the results.

It's interesting how you describe the inside, if you take pictures I would
be more than happy to host the images on my server.

Yes, the Symmetricom people are very hush-hush when you ask them questions
about the inner workings of their stuff. While there is only one firmware
version on the Symmetricom site, it is possible they have a second chip that
doesn't get updated via the flash but does store extra info. Hopefully it is
all generic though as you mention and if the signal is there, then it uses
it.

I would not think you would need to remove the onboard VCTCXO, I'm sure it
would just bypass or use it as a backup.

Probe the 10pin headers and see what you get. I don't think they would send
the signal through the ribbon cable, but you never know. There could of also
been an adapter on the LPRO that did various bits.

Jason


> I have a 2100-I (IRIG only model I think) that I retrofitted 
> with a Trimble ACE-ii GPS module which is quite nice. In a 
> examination of the manual I see that a LPRO Rb oscillator was 
> offered for this unit. I handily aquired a few of these via 
> the Lucent mis-cue a few weeks back (I got mine for the 
> 130.00 BIN- I hit the auction within minutes of the post).
>  
> At any rate, Symmetricom is exceptionally close mouthed about 
> any details- much less any info on the interconnection of an 
> LPRO. Sooo this is going to be a DIY project.
>  
> Things I have gleaned so far from a cursory examination: The 
> LPRO module fits handily via six countersunk screw holes in 
> the left front of the case, by the GPS module. Of couse the 
> Rb will require a second power supply module- which is 
> prepared for with additional screw holes and the AC harness
> has another Molex connector on it. 
>  
> I also believe the firmware for a unit with the Rb option is 
> the same as a basic unit, because there is no reference to a 
> different version for ANY 2100 option. I suspect that either 
> a jumper is made or the presence of the 24Volt supply (which 
> preliminary assesment would conclude being connected to 
> un-used Molex header 'POWER2') would cause the unit to be 
> aware of the Rb module. I also would expect to remove the 
> Crystek 10 Mhz DIP oscillator (U24).  I see a PGA on the 
> board so I hope it doesnt contain any logic relating to the Rb.
>  
> Finally, there are a few .100 10 pin headers- it cant be as 
> simple as a ribbon to one of those headers- the 10Mhz must 
> surely pass thru a coax assembly to one of the 2 SMB type 
> connectors (SMB1, SMB2)? 
>  
> I plan to pull the board and trace out the un-used headers 
> and power2 connector this coming weekend.




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