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From: davew@gvgpsa.GVG.TEK.COM (David C. White)
Newsgroups: sci.electronics,sci.astro,comp.dcom.modems,comp.misc,rec.ham-radio
Subject: Re: N.B.S. Time Service
Keywords: Time Ticks
Message-ID: <918@gvgpsa.GVG.TEK.COM>
Date: 8 Jun 88 05:32:57 GMT
References: <455@trane.UUCP> <4691@watcgl.waterloo.edu> <585@otto.COM> <3335@phri.UUCP>
Reply-To: davew@gvgpsa.GVG.TEK.COM (David C. White)
Organization: Grass Valley Group, Grass Valley, CA
Lines: 23

In article <3335@phri.UUCP> roy@phri.UUCP (Roy Smith) writes:
>	If I call Colorado from New York and get a land line, I'm going over
>maybe 3-4000 miles of path (doesn't make much difference if it's copper
>wire, microwave, or fiber; in reality it's probably a combination of all
>three).  For a 3000 mile path at 300,000 miles/second, that's a 10 msec
>delay.
 
>	The kicker is that commsats are in geosynchronous orbit.  If I
>remember correctly that means an altitude of 23,000 miles, making the path
>length twice that (uplink + downlink) or 46,000 miles.  That's about 150
>msec.

Did I miss something, or were some basic laws of nature
changed when I wasn't looking?  I think we have the classic
apples and oranges comparison case here.  What I think Roy meant
was that the speed was 300,000 km/sec rather than miles/second.
The rest of the conversion from miles to kilometers is left as
an exercise for the student.


-- 
Dave White	Grass Valley Group, Inc.   PHONE: +1 916.478.3052
P.O. Box 1114  	Grass Valley, CA  95945    davew@gvgpsa.gvg.tek.com