[amsat-bb] Re: PC clock

Greg D. ko6th_greg at hotmail.com
Mon May 10 22:47:23 PDT 2010

Hi Larry,

Ok, I understand the need for an accurate clock, though I believe you're expectations for being able to track an overhead pass is pushing the limits of orbital prediction pretty hard.  Another ham I know locally tried this, and ultimately gave up.  His issue was not one of clock accuracy, but of Keps and the mathematics behind them.

But, you've still got a PC that isn't working right, and that bugs me.  I just checked my PC, and it was spot on with WWV (clock changed at the chime).  So, a question...  Did the clock drift before the serial port was installed?  Perhaps what you need is a new driver or a different type of serial port, if you haven't exhausted that route already.  

Greg  KO6TH

Date: Sun, 9 May 2010 21:23:58 -0600
From: W7IN at montana.com
To: ko6th_greg at hotmail.com
CC: amsat-bb at amsat.org
Subject: Re: [amsat-bb] Re: PC clock



During the process of getting a serial port interface that worked
properly with W7-64b, I experienced a myriad of system crashes.  This
is possibly why my clock got off by about +30 seconds.  I often check
my PC's clock against the WWV clock on my wall, especially when
tracking birds.  It's now on to within a second.  If it got off by more
than 2 or 3, I'd want to corrected it; the problem is not Doppler, it's
a near overhead pass (that's when I discovered the PC time error). 
Plus, I want correction automatic and not have to mess with it for a
long time.  I believe the once-a-week default in Win7 for syncing PC
time with Internet server time is too loose.  Once a day or even once
an hour seems better to me.

73, Larry W7IN

On 5/9/2010 7:05 PM, Greg D. wrote:



I know PC clocks are not all that accurate, but we're talking seconds
per month.  Needing to update a clock more often than that probably
isn't due to the PC hardware.  I've never had one be off this much
unless the clock battery was dead, and any PC new enough to run Win-7
isn't going to have that issue.  I would suspect that there is a some
software you are running that is messing it up.  Back in the DOS days,
this was a common occurrence, and I'm surprised to hear about it under
something more modern, but my gut feel tells me that is what is


Maybe a device driver or something else low-level.  Try booting
something else (a "Live" CD of Linux, for example) to prove the
hardware is good.  Go back to Windows piece by piece.  If you can
figure out which it is, then this whole idea of applying bandaids can
go away.


Just a thought,


Greg  KO6TH


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