[time-nuts] FE-5680A Mechanical Question

Chris Albertson albertson.chris at gmail.com
Fri Jan 13 11:15:42 EST 2012


On Fri, Jan 13, 2012 at 3:19 AM,  <EWKehren at aol.com> wrote:
> What we know is that you can set the Rb in 7 E-13. Dithering would allow
> even closer setting, the question is what rate will the Rb accept with out
> loosing lock or deterioration of the performance. Some one should explore
> that.  I am still waiting to se some aging. Taking the 10 MHz output and than
> use an  analog loop and something like a Morion OCXO and you have the best of
> all.
> Digitally controlling the Rb will cut the cost of the control loop in half.
>  For $10 in parts and a PC board for less than $10 using Shera like
> controller  can be realized. What is needed is some one able to do the PIC.
> If some one is interested and able, please contact me off list. A low cost
> GPS or a 1 pps output of a Tbolt be perfect source.
> Bert Kehren

Don't use a PIC for the prototype.  A desktop PC could work as well
and everyone here already has one.   Connect the FE5680 to the PC's
serial port and send commands to adjust it.  The PC also needs to be
able to read a voltage.   Many already have audio input with 24-bit
ADC chips.

Later you can move the C code from the PC pretty much directly to an
AVR.  PICs typically use assembly language, that is harder and limits
the number of people who can contribute changes to the code.  But you
can start with a PC, maybe running Linux or BSD.
Chris Albertson
Redondo Beach, California




More information about the time-nuts mailing list