[time-nuts] Clean 10 MHz ref

Wes wes at triconet.org
Wed Sep 14 16:44:50 EDT 2016


On 9/14/2016 2:59 AM, David J Taylor wrote:
> It is non-trivial to set other than a few embedded frequencies with the existing
> software.  There has been a veiled promise of improved software that remains
> unfulfilled.  It is a GPSDO, although the internal oscillator is a TCXO, not an
> OCXO.  Mine runs on even a laptop USB port.
>
> Wes
> ======================================
>
> Folks,
>
> Mine's running of a standard PC USB port, and the power consumption measures 
> between 220 and 240 mA.
>
> With the supplied software (mine dated 2016-May-10, but that may have been the 
> install date) setting the frequency is simply typing in the frequency in Hz, 
> clicking "Find" and clicking "Update". I've tried a whole variety of random 
> frequencies (e.g. 123.456789 MHz) and the device locks within a few seconds.
>
> One limit is that the second output frequency needs to be related to the 
> first, as far as I can tell.
>
> Cheers,
> David

True for the first frequency.  The second statement may or may not be true, it 
was not clear in the original description of the device.  When I wrote Leo and 
asked about a specific second frequency he did a manual calculation and sent me 
the parameters. From another email reply:

    "Sorry, did not catch your email first time.  Thank you for your custom!

    The numbers are internal settings of PLL chip Si5328 and you can find more
    details here:
    https://www.silabs.com/Support%20Documents/TechnicalDocs/Si53xxReferenceManual.pdf

    You can set other frequencies just by typing them into Output 1 box and
    clicking "Find"  This will find and program the new frequency.

    If you want two separate frequencies at the same time it gets a bit tricky
    and often need manual setup.  In such case let me know what combination you
    would like and i will try to find the correct settings."

While this is process is helpful, it is hardly convenient and frankly me 
deciphering the doc without a Rosetta Stone isn't going to happen.

Wes, N7WS




More information about the time-nuts mailing list