[time-nuts] The Trimble NTPX26AB-06 / Z3801A

Hal Murray hmurray at megapathdsl.net
Fri Nov 21 21:27:49 UTC 2008


> I have the Trimble NTPX26AB-06 and I have established that the I/O
> port (25 way D connector) has the same pin-outs as the Z3801A. Can any
> owners/users of these units advise me on a suitable (proved to work)
> interface adaptor from the RS-422  to RS-232. The unit works fine and
> is producing its 10 MHz output with very good accuracy, but I am
> looking forward to "seeing it" through its interface with TBolt Mon.  

The Z3801A has both RS-422 and RS-232 level conversion chips inside.  What 
gets routed to to the connector is determined by either some jumpers on a 
header or some zero ohm resistors.  So it's easy to modify the unit to 
directly speak RS-232.

I don't know what's in the NTPX26AB, but looking to see if there is an RS-232 
chip seems like a good excuse to open it up and look around.  :)  (If you 
haven't done it already.)

If you want to build an external converter box, I have schematics I found on 
the web many years ago.  They use LTC1318 or MAX3162.  I'm sure there are 
many other chips, but those are probably a reasonable place to start.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.






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