LOL here we go. The answer is actually “none of them”. This is why I have a GPSDO and that’s not even the truth but a well formed opinion.
The actual truth is too complicated for our primitive instrumentation.
Notice I said that the 7260A was "most likely" the most accurate.
For my purpose it will be my "standard" ![Tweak :-/O](https://www.eevblog.com/forum/Smileys/default/smiliey_cal.gif)
As of right now I have no intention of going any further with this time nut stuff. It makes my head hurt.
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif)
geeeeeze med......yer killin' me!
have you been pickin' your feet in Poughkeepsie?
if you own more than 2 counters are you ARE a time nut. but the .5ppm xtal in that 7260a is not gonna cut it. (250 Hz off at 500 Mhz is crap)
not that i am an enabler.....but if you had a decent ocxo like this one you would be confident of only being 5 Hz off at 500 Mhz. (sure...ya' gotta' let it warm up for an hour to get to 1 part in 10^8).
in the pic the 5335a is referenced from a rubidium that measured -1.5 x 10^-11 when compared to the gps standard.
the ocxo occasionally bounced to 10,000,000.01
go ahead....dare me to put that ocxo in a usps box.