[ntp:questions] Re: CHU time source?

Steve Kostecke kostecke at ntp.isc.org
Thu Dec 30 18:33:14 UTC 2004

On 2004-12-30, David Magda <dmagda+trace040726 at ee.ryerson.ca> wrote:

> Reading a bit about CHU service offered by the NRC up here in Canada
> and NTP.
> I borrowed a Sun Sparc 5 (Solaris 8) in relation to other work I'm
> testing, and was curious whether it's as simple as plugging in a
> shortwave radio into the microphone jack and telling NTP (4?) about
> it with 'driver 7' (127.127.7.x).

And you'll need a few symlinks in /dev 

# For audio input:
ln -s /dev/audio /dev/chu_audio

# For serial control of your ICOM (or TenTec RX-320) radio:
ln -s /dev/ttyS0 /dev/icomx       # where x is from 127.127.7.x

The error messages in the log will help you see what you need.

> Has anyone used CHU?

I am on a Pentium90 (24MB) laptop with a TenTec RX-320 radio. I'm using
Tim Shoppa's modified icom.{c|h} files to allow ntpd to control my

These stats are not as good as they might be because I have the serial
control link for the radio temporarily disconnected.

     remote     refid      st t when poll reach   delay   offset  jitter
*CHU_AUDIO(0)  .CHU1.       0 l  115   64  377    0.000    0.229   0.321

ntpdc -c kerninfo

pll offset:           -0.000205 s
pll frequency:        87.072 ppm
maximum error:        0.019299 s
estimated error:      0.00024 s
status:               0001  pll
pll time constant:    2
precision:            1e-06 s
frequency tolerance:  512 ppm
pps frequency:        0.000 ppm
pps stability:        512.000 ppm
pps jitter:           0.0002 s
calibration interval: 4 s
calibration cycles:   0
jitter exceeded:      0
stability exceeded:   0
calibration errors:   0

ntpdc -c sysinfo

system peer:          CHU_AUDIO(0)
system peer mode:     client
leap indicator:       00
stratum:              1
precision:            -18
root distance:        0.00000 s
root dispersion:      0.00250 s
reference ID:         [CHU0]
reference time:       c57ec79c.704b3c3e  Thu, Dec 30 2004 13:29:48.438
system flags:         auth monitor ntp kernel stats 
jitter:               0.000198 s
stability:            0.000 ppm
broadcastdelay:       0.003998 s
authdelay:            0.000000 s

Steve Kostecke <kostecke at ntp.isc.org>
NTP Public Services Project - http://ntp.isc.org/

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