I suggest at least a 10-second delay.
Originally Posted by KD5SPX
Or get Glen to do it.
TOM K8ERV Montrose Colo
While having such an incredibly accurate time interval measuring device available at that really low price qould be cool, without tracibility to a reference standard to set the thing by and to occasionally check it against, it's a great conversation piece.
Sorry, I guess my PMEL is showing! LOL
"An armed society is a polite society. Manners are good when one may have to back up his acts with his life." - Robert A Heinlein
The 'Atomic Clock' you can buy from Radio Shack or Fry's does not have an atomic clock chip. It receives time sync signals from WWV. If the internal clock on the Radio Shack unit is drifty, it can be off as much as 1 second over a day. Once a day it checks the WWV signal and suddenly the clock you synced to it 10 minutes ago is off by one second. This is not important in most situations, but I have timed rally cars by time of day, and we do not use those type clocks for that reason.
Originally Posted by K5RCD
As I understand metrology, one would need a standard four times more accurate than the item being calibrated. And that is? It costs HOW much to use? Biannually, you say?
Originally Posted by KK4AMP
I propose an extraterrestrial reference: pulsar emissions. Now, about that 200 meter dish antenna...
I'm well aware of that. None of the available, reasonable priced clocks have an "atomic chip". It will synch to the nearest second with the radio time, and the time chip in the clock is accurate to less than 1 second / day drift. I have placed both my clocks where they could not receive the radio signal for 3 days, and both were still accurate within 1 second.
Originally Posted by KI6HLD
I have 2 clocks, which are always dead on accurate to each other, and have never varied from WWV time enough for me to detect by eye / ear.
Works just fine for the purpose I stated.
They look to be around $1,500 each when ordered in quantities of 100: http://www.insidegnss.com/node/2446
I'd take it with when visiting folks I didn't really like so it would tell me when to split.
I've thought it over carefully... - I would sell the atomic clock and use the money for something better, maybe a spare HF rig or a really nice VHF/UHF all mode setup w/antennas, feedlines etc..
Originally Posted by KE7HQY
73 DE Charles, N5PVL
The "S" word... It's not the socialism, it's the stupidity behind it.
I have an Efratom 10MHz rubidium frequency standard. It's a BOATANCHOR compared to the newer ones but it does work. It is housed in a Tektronics TM5006 mainframe so it takes up a lot of space around here. Currently it is out in the garage waiting for me to arrange a workbench. No more room in the shack!
Last edited by K7MH; 06-16-2012 at 05:19 PM.
"Oh what a tangled web we weave when first we practice to receive."
-Otto Watt Sept. 5 1925