[time-nuts] WWVB D-PSK document

paul swed paulswedb at gmail.com
Sun Mar 31 22:17:53 EDT 2013


Bob and Magnus no offense taken at all good comments and thats why I
shared. Needs other eyes then just mine. I captured the text in a seperate
document reread tomorrow.
Easy stuff first. Magnus the concerns on the channel are very real and it
really does shift phase significantly. I do see this sometimes at sun rise
and set. When I went to the 22K instead of the 474 K that seemed to allow
things to track the dynamics better. I actually do not believe 22K is the
answer. I believe its at the other end actually of the possible integration
solution. 1M was definitly out.
bob you have numbers of comments I need to chew on. The TL072 cutoff well
below the broadcast band. The other thing noted (Darn good eyes) is the
arrangement of the 2 Xformers. Yes they are what they are its what was in
stock at mouser. No one make IF xformers anymore. So the z is high and the
other side is higher. Great choices. Is what it is.
What are you going to do no one does DC anymore.
Thanks everyone for the comments and John for posting.
Regards
Paul
WB8TSL


On Sun, Mar 31, 2013 at 9:23 PM, Magnus Danielson <
magnus at rubidium.dyndns.org> wrote:

> Hi,
>
> True. The station itself doesn't swing +/- 100 ppm, but the channel you
> recieve it from can alter delay quick enough to annoy you. But the
> phase-change needs to put in context with the time it takes to make the
> phase-change in order to come up with a frequency error.
>
> However, if it shifts a cycle in say 60 s, then it will be 1/(60000*60)
> about 2.77E-7 in relative frequency, which is small enough that an
> unregulated XO variations become a larger issue.
>
> Cheers,
> Magnus
>
>
> On 04/01/2013 02:29 AM, Bob Camp wrote:
>
>> Hi
>>
>> But can you ignore the WWVB signal swing? The beast flips a cycle (or
>> more) as you hit sunrise or sunset. A cycle at 60 KHz is a lot of ppm.
>> Weather this happens fast enough to actually turn it into a tuning issue is
>> the question.
>>
>> Bob
>>
>> On Mar 31, 2013, at 7:36 PM, Magnus Danielson<magnus at rubidium.**
>> dyndns.org <magnus at rubidium.dyndns.org>>  wrote:
>>
>>  Hi,
>>>
>>> Uhm, yes. You want your pulling-range to handle all the drift and tempco
>>> you reasonably can assume, and also that of the application and signal.
>>> Since the signal is WWVB in this case, we can ignore that factor. Also, you
>>> don't want to be completely de-tuned from start either. I'm sure John knows
>>> this already.
>>>
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