[time-nuts] Beginner's time reference

[Justin Pinnix]

I'm hearing a lot of recommendations for types of oscillators, but noone has
asked the question - what is the desired performance?

For me, I wanted a clock that stays within a second of UTC for a year.  I'm
pretty sure the LPRO I bought will exceed that, (though I guess I won't know
for another 12 months).  Of course, I needed a way to evaluate what I built,
so I also picked up a Thunderbolt.  What was that about a tar pit? :-)

I built my own clock/counter circuit, but it was a lot of work.  I see a lot
of Datum 9100s for sale on eBay for under $50.  Has anyone tried out one of
those?

I still need to write up my circuit, but it is similar to (but not based on)
this:  http://www.qsl.net/zl1bpu/MICRO/CLOCK/

Thanks,
-JP

On Fri, Dec 11, 2009 at 8:42 AM, John Miles <jmiles at pop.net> wrote:

> > Bill,
> >
> > he was planning to spend 100 USD on a used Rubidium, I think a Cs is way
> > over his budget ;-)
>
> Luck has more to do with that than money.  My cheapest cesium standard, at
> $500, also turned out to be the only one out of three with a healthy tube.
>  You have to plan on buying a few turkeys.
>
> If you're shopping for a cesium standard on eBay especially, where the
> sellers don't tend to know what they're selling or how to test it, it makes
> sense to bid low and wait until you get lucky.
>
> > But I agree that a Rubidium has a shorter life span and if you get one
> > for 100 USD on eBay, I would expect it to be "worn out" already.
>
> The LPRO-101 I bought from China recently for ~$100 is in good shape (it's
> the dotted blue trace in the plot I posted earlier, measured against the
> aforementioned $500 Cs.)  It locks up quickly, and its lamp voltage is right
> in the middle of the normal range.  Others have had good results from the
> same seller, so I think they're actually pretty safe.
>
> -- john, KE5FX
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>