[time-nuts] E1938A source code/ firmware

[Richard (Rick) Karlquist]

On 7/5/2019 8:20 PM, Glen English VK1XX wrote:
> Has anyone got this , is the PIC read data prohibited ?
> 
> Is it still a closely guarded secret?, there were some very clever and 
> novel ideas used in that slab, in my opinion.
> 
> Glen
> 

Hi Glen.  I worked on this project, but am an RF/Analog
guy.  The product line was sold to Symmetricom 20 years
ago and they didn't continue the E1938A.  At that point,
there were no closely guarded secrets.  I don't know what
happened to the source code.  The last contract manufacturer
for the E1938A was Scotts Valley Magnetics.  You could
contact them and see if they have the PIC info.  In theory,
they would have had to have it to program the PIC's.

The most clever thing in the PIC (AFAIK) is the oven
controller with the double integrator.  "P, I, I^2, D".
Len Cutler was the mastermind behind this.  I believe
he leveraged his experience with double integrators used
in Cs control loops.  I remember him telling me that the
secret was to have an "anti-windup" algorithm.  Whatever
he did, the results were phenomenal.  I spent countless
days in the lab exercising the loop and it always worked
perfectly.

Rick Karlquist, N6RK