[time-nuts] z3801a - serial help and for sale

David Andersen dga at pobox.com
Thu Jun 11 16:39:23 EDT 2015


Thanks for the suggestions!

It turns out the answer was.... my serial dongle was failing.

*head bonk*  I swapped it out for another FDTI-based dongle and suddenly
there's a happy working z3801a.

Before I throw it on eBay, would anyone like a working (yay!) z3801a
modified to take mains power?  I'll throw in a little puck antenna and a
homebrewed rs232 db25-to-db9 cable.  Pictures as per my previous email
about it.

(please CC: me on reply -- I'm stuck in digest subscription and having
issues.)  ((No 'issues' jokes, please. :))

I'll note there's a risk that putting the switcher in it causes added
noise.  I haven't measured it precisely enough to tell.  I didn't need
nanoseconds for what I was using it for, but I did want it to be pain-free
to plug in and use.

 -Dave


…
On Thu, Jun 11, 2015 at 1:18 AM <time-nuts-request at febo.com> wrote:

> ---------- Forwarded message ----------
> From: James C Cotton <jim.cotton at wmich.edu>
> To: Discussion of precise time and frequency measurement <
> time-nuts at febo.com>
> Cc:
> Date: Wed, 10 Jun 2015 16:26:17 -0400 (EDT)
> Subject: Re: [time-nuts] z3801a - serial help and for sale.
>
> David,
>
> Using a USB dongle with an Apple Mac Laptop works fine for me.
>
> The chip is a FTDI FT232BL.
>
> Drivers from the FTDI site.
>
> In "terminal or console" use one of the following commands:
>
> [generic $5 dongle with no serial number]
>
> cd /dev
> screen tty.usbserial
>
> [xs880 with a serial number,
> http://www.usconverters.com/usb-serial-adapter-xs880]
>
> cd /dev
> screen tty.usbserial-A101OFXZ
>
> Having one (or more) with a serial number(s) allows several to work at the
> same time...
> I use the same USB-serial converters on windows PCs too.
>
> Jim
>
>
>
> ---------- Forwarded message ----------
> From: Scott McGrath <scmcgrath at gmail.com>
> To: Discussion of precise time and frequency measurement <
> time-nuts at febo.com>
> Cc:
> Date: Wed, 10 Jun 2015 16:50:51 -0400
> Subject: Re: [time-nuts] z3801a - serial help and for sale.
> Try going through all the speeds starting at 300.  Sounds like a baud rate
> mismatch to me from the symptoms
>
> Also try 8 bits 1 stop no parity
>
> Content by Scott
> Typos by Siri
>
> > On Jun 10, 2015, at 10:28 AM, David Andersen <dga at pobox.com> wrote:
> >
> > I'm throwing my hands up in the air - I don't have the time to wrestle my
> > silly mac into trying to talk to the box, unless someone has quick advice
> > on something I might be doing wrong.
> >
> > z3801a, jumpered to RS232, modified with an internal switching power
> supply
> > (see photos below).  Power light comes on, unit is outputting stable
> > 10MHz.  Doesn't GPS lock, but that makes sense, since I haven't been able
> > to issue a SURVEY command and I don't live where I used to.
> >
> > The internal green status light is blinking (as normal), suggesting that
> > it's probably happy and I'm an idiot for not being able to make it work,
> > but I don't vouch for anything about it past the 10mhz being there.  The
> > double-oven oscillator is clearly happy given the 10mhz (compared
> against a
> > working Thunderbolt).
> >
> > Hooked up a serial cable at 19200, 7, O, 1, but only got a garbled little
> > prompt back - no response to standard z3801a commands.  I *think* I have
> > the cable configured properly.  I opened it up and checked the RS232
> > jumpers and they're correct.
> >
> > I'm open to advice on getting the serial working under my Mac or Linux,
> or
> > anyone who wants to relieve me of the burden of z3801a ownership and
> take a
> > risk that it's a fixer-upper. :-)  I suspect that in some previous life,
> I
> > switched it over into a binary mode of some sort while using it to sync
> > something, but I can't for the life of me remember what I might have
> done.
> >
> > Some reasonable price plus shipping and it's all yours... I'm trying to
> > de-clutter in preparation for a sabbatical on the other side of the
> country.
> >
> > Pictures:
> >
> > https://www.dropbox.com/s/ursszjgie8m1xj8/2015-06-09%2011.57.16.jpg?dl=0
> > https://www.dropbox.com/s/it8d2f65ztn4rkq/2015-06-09%2011.57.24.jpg?dl=0
> > https://www.dropbox.com/s/1p1g6xrapzdmvzh/2015-06-09%2011.59.56.jpg?dl=0
> >
> > Thanks!
> >
> >  -Dave
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
>
>
>
> ---------- Forwarded message ----------
> From: Bob Camp <kb8tq at n1k.org>
> To: Discussion of precise time and frequency measurement <
> time-nuts at febo.com>
> Cc:
> Date: Wed, 10 Jun 2015 17:27:36 -0400
> Subject: Re: [time-nuts] z3801a - serial help and for sale.
> Hi
>
> Normal drill for this sort of thing:
>
> 1) First connect the serial dongle back to back (output to input) and make
> sure
> it gives you back what you type in. If not, find another dongle.
>
> 2) Check the output levels from the Z3801 with a scope. It should be
> swinging at least
> +/- 5V and more like +/-12. The key thing here is that the swing is the
> same in both directions.
>
> Then, in combination, try each of the following:
>
> 3) Try the usual suspects in terms of parity: 8N1, 7E1, 7O1
>
> 4) Try the usual speeds: 4800, 9600, 19200
>
> A quick power cycle between each of the 9 possibilities should get it
> feeding
> out something that you can recognize. Yes this is a generic approach, but
> sometimes
> the generic one is quicker than doing a bunch of research, looking for
> notes on how you
> switched the thing around back months ago ….
>
> Bob
>
> ---------- Forwarded message ----------
> From: Hal Murray <hmurray at megapathdsl.net>
> To: Discussion of precise time and frequency measurement <
> time-nuts at febo.com>
> Cc: hmurray at megapathdsl.net
> Date: Wed, 10 Jun 2015 18:50:11 -0700
> Subject: Re: [time-nuts] z3801a - serial help and for sale.
>
> kb8tq at n1k.org said:
> > 2) Check the output levels from the Z3801 with a scope. ...
>
> > A quick power cycle between each of the 9 possibilities should get it
> > feeding  out something that you can recognize. Yes this is a generic
> > approach, but sometimes the generic one is quicker than doing a bunch of
> > research, looking for notes on how you switched the thing around back
> months
> > ago ….
>
> If you have the scope out, you can easily check the baud rate and with a
> bit
> more work you can probably get the parity.



More information about the time-nuts mailing list