[time-nuts] Re: Isotemp OCXO question

[Robert DiRosario]

This is just a little "fun" project.  I"m sure any of my GPS receivers 
will be more accurate by several orders of magnitude.

So does anyone know how to "decode" the Isotemp model numbers, assuming 
there is some pattern to them?

Robert


On 08/19/2021 09:19 PM, Bob kb8tq wrote:
> Hi
>
> The issue you run into is that the fancy devices tried to derive information from
> the phase of the WWVB signal. With an “AM only” receiver accuracy in the 10’s
> (or 100’s … yikes ….) of ms was pretty common. With a phase oriented approach,
> you could get into the 100’s of us. Indeed there is a lot of fine print involved with
> any WWVB claims.
>
> The change over did not impact the typical WWVB watch or an AM based receiver.
> It very much messed up any of the fancy timing stuff.
>
> Bob
>
>> On Aug 19, 2021, at 9:09 PM, Robert DiRosario <ka3zyx at comcast.net> wrote:
>>
>> I have a MAS6180C AM receiver chip, on a board with a few other parts to complete the receiver.  I did not make the board, it came from
>> Universal-Solder Electronics in Canada.  The date on the chip datasheet is 2014 and on the receiver board 2016, so after NIST messed up WWVB in 2012.
>>
>> Robert
>>
>>
>> On 08/19/2021 07:23 PM, Bob kb8tq wrote:
>>> Hi
>>>
>>> It’s a good bet that whatever the spec on that Isotemp OCXO, it’s way better in terms
>>> of temperature and aging then the DS3231. Is it still on frequency (however many years
>>> later …..) who knows ….
>>>
>>> Many of the “time oriented” WWVB devices stopped working when they put in the new
>>> modulation scheme. It’s a pretty good bet that this applies to the device you have.
>>>
>>> Bob
>>>
>>>> On Aug 19, 2021, at 6:55 PM, Robert DiRosario <ka3zyx at comcast.net> wrote:
>>>>
>>>> I got a  Trak Systems "Time Code Translator" from ebay.  It's a 1U box with large LEDs for DOY and H/M/S that translates IRIG-A to NASA-36 time code.  I plan on using the case for my WWVB clock.
>>>>
>>>> Unexpectedly it has an Isotemp OCXO in it, model OCXO59-11-2, frequency marked as 1.000 MHz  The Isotemp website is more or less dead, it has no information on it.  Does anyone have any information on this model, like how accurate it is?  It has only three wires, which I assume are power, ground and output, with no EFC input.
>>>>
>>>> One thing that I'm sill note sure about is what to do when the receiver is not receiving WWVB.  I was thinking of using something like the DS3231 RTC module.  If this OCXO is better, I may use it.
>>>>
>>>> Thanks
>>>>
>>>> Robert
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