[ntp:questions] how do you like the Trimble Resolution T

Chris Albertson albertson.chris at gmail.com
Wed Feb 29 23:12:50 UTC 2012


On Wed, Feb 29, 2012 at 2:29 PM, Bruce Lilly <bruce.lilly at gmail.com> wrote:
> On Wed, 29 Feb 2012 14:16:23 +0000, Ron Frazier (NTP) wrote:
>
>> Other than the Sure board which has been mentioned, are there any other
>> modern, hi sensitivity, timing GPS's which cost less than $ 100.  Many
>> of the ones mentioned seem to be older technology like this Trimble.

Don't worry.  Even the UT+ which is well over ten years old is
fantastically good compared to what NTP needs.   It  has better specs
then many newer units and for timing, I'd say better specs then MOST
new units.    $100 is a good budget.  You can buy a $25 antenna and a
$20 GPS receiver and some cables and a power supply.     I can safely
say that anything with the "trimble" name on it, if it was designed
for timing is almost "overkill" for use with NTP.

As long as it is a timing (not a nav) GPS and you plu the PPS into a
real serial port (not USB) you will be good to go with accuracy as
good as NTP can handle.    But those are importent: (1) timing not nav
and (2) real rs232 serial.    Once you have those two the rest is just
personal preferences and what you were about to find on eBay that day.

Now if you needs included precision timing (something NTP can't do)
and you cared about nano and pico seconds and frequency standards at
the 1E-13 level then yes things that NTP can't notice become
important.

The lowest cost, good units are the UT+ and then search eBay for 26dB
antenna.  And yo'll find a bullet shape white one.   These will fit on
a standard American 3/4" iron pipe flange with 4 bolts.   That would
be the lowest cost profesional level setup and will run with the PPS
at about 50nS (1 sigma)  But there are many other good setups.
Don't worry about if they are "new" tech.   It's like worrying if a
1968 Chevy Corvett is fast enough to get  you to work in the morning.


Chris Albertson
Redondo Beach, California


More information about the questions mailing list