[time-nuts] Re: James Miller/Brooks Shera GPSDO 10 MHz

[Lloyd Blythen]

Great outcome Merv. Pleased to hear it, and thanks for your feedback to the
list.

Regards,

Lloyd
ZL2LEB

On Thu, 22 Sept 2022 at 01:17, Mervyn Thomas via time-nuts <
time-nuts at lists.febo.com> wrote:

> Hi All,
>
> An update on the resolution of my problems with my unit.
>
> I had a component value in the R5, R6 divider on the DAC output wrong -
> 4.7K instead of 470R and while this had not caused any noticeable
> difference over the many years it had run properly it obviously became a
> problem in that it would no longer allow an EFC control voltage to the
> oscillator sufficient to keep it disciplined.  I inserted a 470R and
> also changed the DAC from the AD1861 that had been in for years and
> replaced it with a PCM61P which may or may not have been part of the
> solution.
>
> I also, with the help of my Son-in-law, copied the PIC16F867A
> microprocessor using Matlab and a Pickit 3 on to another spare PIC so
> now have 2 PIC's with the Auto-N function.
>
> My SIL also wrote a Terminal program that utilizes the three 5 digit
> numbers available from the DB9 ASCII I/O to a Terminal program.  I have
> attached a pic taken on my phone (not a very good one) showing just the
> "plot" tab results of the DACvalues and Phase detector values for each
> 30 second.   It shows the fairly wild gyrations at turn on of the unit
> and how it eventually settles down to lock.  He still has a few further
> enhancements to make but I found it was a very useful program.
>
> Merv  VK6BMT
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe send an email to time-nuts-leave at lists.febo.com



-- 
Please consider supporting the EFF to keep the Internet open and neutral
<https://www.eff.org/files/2021/12/20/member-badge-2022b.jpg>