Re: 3.22 not sending PPS to SHM

[Gary E. Miller]

Yo David!

On Fri, 15 Jan 2021 07:57:48 +0000
David Taylor <gm8arv@yahoo.co.uk> wrote:

> In this configuration, the PPS is coming over the GPIO, and is 
> independent of the serial connection. Here, ntpd type 22 driver does
> not need a serial connection.

I write the howto, I'm aware of that.

But you fail to note that the type 22 does not use KPPS, so you have
a noticable increase in jitter.

> On most of my systems I'm using that configuration, with multiple
> local stratum-1 and pool internet sources.  The PPS is a nice add-on
> for much better time-keeping, but it's not essential.  In practice
> there have been no problems - except once when a GPS-jammer equipped
> vehicle drove past!

In addition to the loss of accuracy, there will be instances of
seconds jumping.

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        gem@rellim.com  Tel:+1 541 382 8588

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