[time-nuts] Best Chance GPS module

Nick Sayer nsayer at kfu.com
Sun Mar 19 01:04:09 EDT 2017

Was the LED on the PPS pin or on the FIX pin?

The FIX pin is nothing like the PPS output. Frankly, I’m not 100% sure what the rules are for it. When things are working properly, it blinks at 0.5 Hz, but the leading and trailing edges are something like 120-150 msec after the second. It’s very, very loose. My own interpretation is that the controller flips the bit when it’s got nothing better to do.

I’ve not witnessed the actual PPS pin being toggled when GPS isn’t available, but it’s not a failure mode I’ve expended a lot of effort to examine.

> On Dec 1, 2016, at 7:44 AM, David J Taylor <david-taylor at blueyonder.co.uk> wrote:
> Venus838LPX-T.   Seems to go into a non-locked state for a proportion of the time but still emits a PPS signal, which increasingly deviates from true UTC.  That's using a 25 mm square 28 dB active patch antenna, similar to the antennas on other similarly located GPS receivers.  This was indoors, on the top floor of a two-storey building, with just the power fed to it, watching the LED flash.
> Maybe I was unlucky?  I wonder what experience others have?

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