[Elecraft] Subject: Re: KXBC3 clock drift

[Bill Frantz]

There is a difference of about 15 seconds between GPS time and 
UTC time. GPS time does not include the recent leap seconds. The 
GPS message includes the current difference between GPS time and 
UTC. I don't know which time the JT modes use, probably UTC.

See: 
<https://en.wikipedia.org/wiki/Global_Positioning_System#Timekeeping>, 
and <https://en.wikipedia.org/wiki/Time_standard>. For an idea 
of how complex the idea of time really is, see <https://en.wikipedia.org/wiki/Terrestrial_Time>.


The ideal programs to have automatically update the K3(S) and 
KX3 clocks would be logging programs and utilities that are 
running "all the time". RUMlogNG, N2MM, Win4K3Suite, etc.


When I built my BeagleBone Box, a low power computer using a 
BeagleBone system board, I had to add a real-time clock. I chose 
a high precision one, the ChronoDot - Ultra-precise Real Time 
Clock (v2.1) from Adafruit part# 255 = $17.50. I wanted 
precision in case I wanted to run JT modes while out in the wilderness.

I just checked it and found it 23 seconds slow compared with 
NTP. It has been at least 5 months since I synced the clock on 
that computer, and probably a lot more. Not too bad for a clock 
that runs off a button battery. (Hmmm, that describes my watch 
too, but the ChronoDot is significantly more precise.)

73 Bill AE6JV

On 8/28/16 at 2:03 PM, kl7uw at acsalaska.net (Edward R Cole) wrote:

>But if you are off the grid then some other time std is 
>needed.  GPS time is probably the answer.  I bought a GPS with 
>USB dongle for under $50 dollars which there is software to 
>update the computer time.
>
>Now a utility on my computer with access to accurate time that 
>could be downloaded to my K3 once per day or once per week 
>would be nice.  It could elicit the K3 Utility program to 
>connect and update the K3 clock, automatically.  No change to 
>the K3 clock hardware would be needed.
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