[time-nuts] Is there any IRIG-B hardware decoders available?
paulswedb at gmail.com
Tue May 14 16:43:41 EDT 2013
Boy Chris I don't know what to say here I use IRIG B decoder displays and
they have been happy with my free running xtal oscillator for 12 years. I
do not recall IRIG B making phase lock a requirement. I use gps to get a
time stream then a SXB micro to convert that to IRIG B...
On Tue, May 14, 2013 at 1:35 PM, Chris Albertson
<albertson.chris at gmail.com>wrote:
> OK the 555 timer is not so good of an idea. You need a phase locked
> 1KHz oscillator.
> You can also buy IRIG cards for the PCI bus. We used them where I
> used to work. They are not cheap. Almost any company that working in
> timing or telemetry will have these cards.
> But still if the goal is to have the computer's system time track
> irig, use NTP. It should be easy to build a phase locked 1KHz
> oscillator. 1K is such a low frequency. I'd thing a 4046 chip would
> do the job.
> On Tue, May 14, 2013 at 10:04 AM, Esa Heikkinen <tn1ajb at nic.fi> wrote:
> > Chris Albertson kirjoitti:
> >> NTP will so this. There is an IRIG reference clock. You really do
> >> want to use NTP to discipline the PC's clock. Almost every other
> >> method is worse and causes time discontinuities.
> >> If you happen to have TTL level IRIG it s very easy to convert it to
> >> amplitude modulated IRIG. The standard is a 1KHz tone.
> >> Build a cheap 1KHz oscillator. A 555 timer is good enough. Then you
> >> a single transister if IC time switch to modulate the amplitude of the
> >> signal. The details are not critical.
> > That's good idea if the phase of the 1 kHz signal is not critical?
> > I checked the IRIG-B signal with oscilloscope and looks like the 1 kHz
> > signal's phase is locked to the time signal. The bits will always start
> > stop at exactly same phase. That makes sense because with phase detector
> > could be possible to get very accurate timing from the 1 kHz signal -
> > better than following the amplitude only. That's one reason why I was
> > interested about chipsets; if they can follow the phase also. I think if
> > design any hardware for that it should follow the phase also? It may be
> > complex...
> > Does anyone know if the soundcard based IRIG decoder will follow the
> > also, or only the amplitude (?)
> > --
> > 73s!
> > Esa
> > OH4KJU
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> Chris Albertson
> Redondo Beach, California
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts