[time-nuts] Lady Heather's Tbolt oscillator auto-tune function

Lars Walenius lars.walenius at hotmail.com
Tue Sep 13 16:57:17 EDT 2016

Can anybody say more about the integrator term in the Tbolt? In the Arduino GPSDO I have, I use 1/TC/TC/damping and use damping = 2. I see Nick Sayer do the same but use damping 1.75. Simulations I have done in Excel seems to indicate that a damping in my sense of about 3 could be better to minimize overshoots.

Having looked at old data I have found on Time nuts seems to indicate that the Tbolt uses 1/TC/TC/damping/damping/2?


>Warren wrote:

>If you have a good antenna setup and a constant temperature environment:

>The way to get the lowest noise over short time periods on a TBolt is to set
the TC setting as high as you can (typically 500 to 1000+), and set the
Damping factor as fast as you can (typically 0.7 to 1).

>The reason is that the Tbolt has a simple basic PI phase lock loop
>The Proportional gain is a function of 1/TC and the Integrator gain is a
function of the damping.

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