[time-nuts] How phase stable is rg59 or alternate coax
jimlux at earthlink.net
Mon Nov 21 13:33:32 EST 2016
On 11/21/16 6:38 AM, Scott Stobbe wrote:
> If you had 30 ft of rg59 outdoors seeing maybe 10 degC swings everyday,
> would the propagation time be stable to ps? ns?
Figure it's copper, so 16 ppm/deg C. velocity factor is about 2/3, so
30 ft is about 45 nanoseconds. about 1ps/degree
Really, you also need to look at the effect on the propagation velocity
of the radial expansion of the coax, too, and the change in epsilon.
You can look up a "phase vs frequency" curve for most coax which factors
all of this in.
> On Sun, Nov 20, 2016 at 7:04 PM Hal Murray <hmurray at megapathdsl.net> wrote:
>> Is that even a sensible question? Is there a better way to phrase it?
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