[time-nuts] Adafruit (MT3339) problems today

Chris Albertson albertson.chris at gmail.com
Fri Apr 11 16:11:28 UTC 2014


On Thu, Apr 10, 2014 at 2:48 PM, Bob Stewart <bob at evoria.net> wrote:

> .... The only particular anomaly I can see is that it uses satellites
> close to the horizon for position fixing.I'm getting a reported SNR of 39
> at 5 degrees elevation and 37 at 3 degrees, though I notice the sat at 3
> degrees is not being used to calculate position.  I never got around to
> finishing the choke ring antenna with those pie pans.  Maybe that needs to
> move higher on my priority list.
>

Does the GPS' command set allow you to set a horizon mask?   Some of them
have a setting where you can specify a minimum elevation angle.  10 degrees
is reasonable.  So nothing within 10 deg. of the horizon is used.

I don't think WAAS is going to help with 150ft jumps.  It is more for "fine
tuning"

What you really need to do is spend $20 on a timing mode GPS, even an older
Motorola Oncode has a self survey and fixed location mode.  Pick a really
good spot for the antenna



-- 

Chris Albertson
Redondo Beach, California



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