K3 RTC accuracy

[Arnie Grubbs]

Hello,  I was wondering if anyone has noticed the accuracy of the
real time clock in their K3?

Mine seems to be loosing about 1 sec. for every min. that goes by
as compared to WWV on 2.5 Mhz if left on.  If I shut the rig off
and re-power it, jumps to some goofy time and date. Today the
date shows up as 19.36.41 and the time jumped 3 hours and 40 min.
ahead of where it was set when I cycled the power.

Anyone else have something similar happening or is it just my rig?

Thanks in advance for any info you can share.

73 - Arnie KA0NCR
K3 #185



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[M0XDF]

Yes, mine too looses seconds, but not sure how much, less that you are
seeing (about 30 seconds in a week or so), I'll note it now.

It doesn't come up with a bad time or date when powered on - check your
internal battery is ok and installed the correct way around.

On 24/1/08 11:53, "Arnie Grubbs" <[hidden email]> sent:
> Hello,  I was wondering if anyone has noticed the accuracy of the
> real time clock in their K3?
> Mine seems to be loosing about 1 sec. for every min. that goes by
> as compared to WWV on 2.5 Mhz if left on.  If I shut the rig off
> and re-power it, jumps to some goofy time and date. Today the
> date shows up as 19.36.41 and the time jumped 3 hours and 40 min.
> ahead of where it was set when I cycled the power.
> Anyone else have something similar happening or is it just my rig?
> Thanks in advance for any info you can share.
--
Many ideas grow better when transplanted into another mind than in the one
where
they sprang up. -Oliver Wendell Holmes, Jr., US Supreme Court Justice
(1841-1935)


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[Julian, G4ILO]

Arnie Grubbs wrote

Hello,  I was wondering if anyone has noticed the accuracy of the
real time clock in their K3?

Mine seems to be loosing about 1 sec. for every min. that goes by
as compared to WWV on 2.5 Mhz if left on.  If I shut the rig off
and re-power it, jumps to some goofy time and date. Today the
date shows up as 19.36.41 and the time jumped 3 hours and 40 min.
ahead of where it was set when I cycled the power.

Anyone else have something similar happening or is it just my rig?

Thanks in advance for any info you can share.

Mine loses about a second a day, compared to my radio-controlled clock or my NTP-regulated computer. I have not observed any other problems with it..

[Leigh L. Klotz Jr WA5ZNU]

A feature for the K3 firmware updater to set the clock to the computer's
time might be nice.
Leigh/WA5ZNU
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[Carl Clawson]

Oooohh this brings back painful memories, but thankfully they are somewhat
vague after a couple decades. MS-DOS could show similar problems because 1)
it only read the (fairly accurate) RTC at boot and used the much less
accurate CPU clock to keep time thereafter, and 2) if you used the clock
interrupt for your own purposes -- driving stepper motors in our case -- you
could lose additional clock time if you dawdled too much. We dawdled -- a
lot. Eventually there came available aftermarket clock drivers that would
read the RTC for everything and not depend on an inaccurate and potentially
unreliable clock. I think we ended up writing our own driver after first
discovering several other ultimately flawed "solutions".

A typical spec for a CPU clock used to be 0.01%, but that would only have
you off by at worst about 9 seconds per day. This is still far worse than a
typical quartz watch which is good to more like one second a week.

73, Carl WS7L

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[Alan Bloom]

Wow, a second per minute is 16,667 ppm error.  That can't be due to the
accuracy of the 32 kHz resonator - there's no way it could be off that
much.  It sounds like a programming error where it's counting the
seconds incorrectly, but I doubt that could be the problem since it
would have shown up before this.

> If I shut the rig off
> and re-power it, jumps to some goofy time and date. Today the
> date shows up as 19.36.41 and the time jumped 3 hours and 40 min.
> ahead of where it was set when I cycled the power.

Sounds like the 3V battery is dead or disconnected.  I would check the
power to the real-time clock chip (U16 pin 8 on the front panel board)
while flexing the board and see if perhaps it's intermittent.  Do that
both with and without power turned on.  You shound measure almost 5V
with power on and 3V with power off.

Al N1AL


On Thu, 2008-01-24 at 03:53, Arnie Grubbs wrote:

> Hello,  I was wondering if anyone has noticed the accuracy of the
> real time clock in their K3?
>
> Mine seems to be loosing about 1 sec. for every min. that goes by
> as compared to WWV on 2.5 Mhz if left on.  If I shut the rig off
> and re-power it, jumps to some goofy time and date. Today the
> date shows up as 19.36.41 and the time jumped 3 hours and 40 min.
> ahead of where it was set when I cycled the power.
>
> Anyone else have something similar happening or is it just my rig?
>
> Thanks in advance for any info you can share.
>
> 73 - Arnie KA0NCR
> K3 #185

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