[time-nuts] HP Z3801A Communications

Hal Murray hmurray at megapathdsl.net
Sat May 17 23:03:52 EDT 2008

magnus at rubidium.dyndns.org said:
> It is not that much work really, and it becomes much more usefull
> afterwards. 

What fraction of the people on this list are geeky enough to take the cover 
off just for the hell of it?  :)

> You can do quite alot once you have in online. There are even more
> than the manual would make you beleive. 

Is there a list of the other commands available?  What are they good for?


Aside from taking it apart, you need to remove a handful of 0R SMT jumpers 
and put 3 of them back on different places.  I think they are 0805.  My eyes 
are pretty old, but I can do 0604 if I have two good soldering irons.  0805s 
are a piece of cake.  Removing them is harder with only one iron, but it's 
not a big deal (IMHO) if there isn't anything complicated like a connection 
to a plane that sucks a lot of heat.

If you want a PPS signal via RS-232, things get more complicated.  The first 
step is to lift a pin to free up a driver.  If you want it on the normal DCD 
pin, you have to cut a trace.  I avoided that by using a convenient unused 
pin on the DB-25 because I was making my own 25-9 adapter so it was easy to 
customize it.

Here is another set of pictures, ideas, and directions (thanks to Jeff Mock):

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

More information about the time-nuts mailing list