[time-nuts] Chronometer contest sponsored by IEEE Spectrum
Hal Murray
hmurray at megapathdsl.net
Fri Nov 30 00:58:58 EST 2007
> Are surplus parts such as Ebay OCXOs OK? (That's an 'open market' to me!)
I got eight 3 MHz OXCOs for $32. They don't have electric tuning, but the
one I played with seems pretty stable. It takes a significant dip if I grab
the can with my fingers but there isn't any obvious 24 hour pattern.
Maybe there should be several categories:
Sync to WWVB
Sync to 60 Hz from the wall.
Sync to GPS (you can get USB GPS units well under $100)
Watch crystal - 32 KHz
Other crystal
Good local osc (TCXO, OCXO, ...)
External frequency source - focus on display
Say 10 MHz coax with power over the coax.
Longest battery life (lowest power)
Best accuracy per dollar
measured over a month
using Digikey's one-off pricing (or any major supplier)
????
Coolest as determined by judge's whimsy.
Any other categories the judges think appropriate.
Built out of stuff in your junk box
Only "junk" allowed
Cesium OK if you already have one :)
> Display should be seven-segment LEDs
That seems like a strange restriction. It cuts out a lot of innovation that
could be done on the display. It also mostly eliminates the battery powered
area.
Using the eye-ball to measure goodness of a clock seems like the wrong
approach. How about adding a PPS test point to the requirements?
> we're looking for a usable appliance, not just a science project.
What's wrong with science projects? DIY stuff is inherently a project.
Sometimes it's science, sometimes art, sometimes engineering, sometimes just
fun.
--
These are my opinions, not necessarily my employer's. I hate spam.
More information about the time-nuts
mailing list