[ntp:questions] ntp version 4.2.7p257-o

unruh unruh at invalid.ca
Tue Feb 21 17:07:07 UTC 2012


On 2012-02-21, Mark C. Stephens <marks at non-stop.com.au> wrote:
> Oh no I have a tom tom for the Car ;)
>
> I have everything I need in place, a couple of spare 27db bullet antennii already up on the eaves, outside, I can knock up PSU's or TTL convertors as needed.
>
> Cables already run, I can crimp bnc, sma, tnc on the lab end as needed.
>
> Must have, is a GPS RX that doesn't wander halfway across town, has a regular PPS without jitter and outputs PPS and sentence the type 30 refclock can use!

Type 30?
The Sure board would seem to fulfill your needs. And it is the cheapest. 
No idea if your antennae would work with it. 
It has an antenna with about a 4m lead. 

I am not sure of the accuracy of the sure. It's pulse is of the order of
10ns in width (if you do not go through the rs232 conversion) but
whether or not it accurately corresponds to the GPS time I do not know.
It does not report the digitization error and some of the Motorola
Encore do, so if you really need ns precision, it is probably not the
right board for you. If you need us, it is probably fine. 


> Basically an accurate receiver vs. $$$. I can't do more than 100 bucks I guess.
>
> That's about it, I can't afford to buy everything available ):
>
> It's a shame I can't use the HP GPS I have now. 
> The jitter sits on 0.02 all day long but refuses to work under windows ntpd, wonderful under FreeBSD but no PPS workee under windows.
>
> Dave and I have been over, under and around everything to no avail. We thought to try another receiver.
>
> I just had a thought, try it on another windows boxen! Amazing how come I didn't think of that before!
>
> I have the same chassis and system board the freebsd is running on, I'll load windows on and see if that maketh any difference.
>
>
> Many thanks,
> Mark
>
>
>> -----Original Message-----
>> From: Chris Albertson [mailto:albertson.chris at gmail.com]
>> Sent: Tuesday, 21 February 2012 1:06 PM
>> To: Mark C. Stephens
>> Subject: Re: [ntp:questions] ntp version 4.2.7p257-o
>> 
>> On Mon, Feb 20, 2012 at 4:54 PM, Mark C. Stephens <marks at non-
>> stop.com.au> wrote:
>> > Hi Dave,
>> >
>> >
>> > Not being a mind reader you wouldn't know I am using a HP GPS.
>> > I am still looking at ordering a Sure, but I am stuck between:
>> > A Garmin 18LV, A Sure GPS Mk I or a Sure GPS Mk II or this:
>> >
>> http://www.twig.com.au/store/product_info.php?products_id=108&osCsid
>> =f
>> > 1b73789c789ab97bd81813764de5d69
>> >
>> > Someone help me make up my mind so I can order something already!
>> 
>> Make a list of "must haves" and "like to haves" and a budget and list
>> the requirements in order.   How will you physically mount the antenna
>> and route cables.  What accuracy do you need?   Can you solder you own
>> cables?   Just list this all out.
>> 
>> If you post your list here people will be able to give informed advice
>> otherwise it is as if I were to post "what kind of car should I buy"
>> --
>> 
>> Chris Albertson
>> Redondo Beach, California



More information about the questions mailing list