[time-nuts] Embedded NTP server ideas and feature requests

[Chris Albertson]

Features?
1) Power the thing with "power over Ethernet" then you can remove the
coaxial power input.  Also this would make it real easy to place the
server right at the antenna location.   You would simply run cat-5 up
to the roof.  The mount the antenna on top of a water proof box with
the server inside the box.  If power has to come in via the coaxel
power connection to a wall-wort then it wil be hard to mount this
server outdoors, near the antenna.

2) You really should make provision for a 5V antenna.  All it will
cost is a tiny little 78L05 to provide a few milliamps.  Put a jumper
on the board to select the antenna voltage.

With the GPS on the server using power over Ethernet makes even more
sense because peoplewill want to place the seaver very near the
antenna to make the wiring simpler.  Wha not go all the way and put a
patch antenna on the board?





On Sat, Feb 9, 2013 at 2:27 PM, Michael Tharp <gxti at partiallystapled.com> wrote:
> Greetings time-nuts,
>
> I've finally gotten the software for my NTP server project to the point
> where I'm comfortable shipping the boards I have now, so it's about time to
> spin the next revision. If you could take a minute to look over the feature
> list and let me know on- or off-list what you'd like to see, hardware or
> software, I'd really appreciate it.
>
> Here's the current product. I have 3 built and tested, so if you like what
> you see and you have a GPS to hook it up to I'd be happy to send one your
> way.
>
> https://www.tindie.com/shops/gxti/laureline-gps-ntp-server/
> http://partiallystapled.com/2013/01/laureline-gps-ntp-server/
>
> There are a few things that I will definitely be changing. For one, instead
> of a "bring your own GPS" I will be integrating a u-blox NEO-6M receiver.
> It's not a timing receiver, but from what I've been able to find on this
> list it is quite suitable for NTP. Should add about $10 to the cost but
> compared to a $30 used Resolution T or similar that's a good tradeoff. There
> will be a header where you can connect your own favorite receiver.
> Alternately, the NEO-6T timing receiver uses the same footprint and be
> soldered down instead, but is much harder to source.
>
> The 5V antenna power will also be removed so there is one less power supply
> to deal with, but if you have an antenna that requires more than 3.3V then
> you can use a header to supply any voltage that it might need. I will also
> be beefing up supply filtering. It performs well now but I want to make
> absolutely sure that EMI is a non-issue.
>
> I've heard some people say they'd like a 10MHz output from the server. I can
> break out the (digital) 10MHz clock from the VCXO, and/or provide a way to
> connect your own OCXO if people are interested. The latter will require some
> kind of adapter though as most OCXOs need more than the 3.3V VFC used here -
> a simple op-amp gain will work fine - and a limiter might also be needed to
> digitize the sine-wave coming in from the OCXO. These can be dealt with
> separately, though.Simply adding an ovenized oscillator and timing GPS one
> can turn Laureline into a pretty good GPSDO.
>
> On a semi-related note, I have two PPS Piggies in stock in my Tindie store
> as well, so anyone with a Trimble Resolution T or SMT who needs a way to
> hook them up should take a look.
>
> Happy ticking,
> -- m. tharp
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-- 

Chris Albertson
Redondo Beach, California