[ntp:questions] Re: WWV audio driver, FreeBSD, Can't seem to get it going
David L. Mills
mills at udel.edu
Tue Jun 7 18:18:18 UTC 2005
Danny, et al,
There is a good deal of electrical engineering theory and practice in
the WWV/H and CHU and IRIG audio drivers. In fact, I use those drivers
as examples of optimum demodulation/decoding in my course on
digital/analog communications engineering. I have no problem should
somebody send a bug report to bugzilla, but the only person to fix
problems with the audio drivers will be me. As I don't read bugzilla
reports directly, the best course is to send reports about the audio
drivers directly to me and, in particular, to this newsgroup.
> Roger, if you can file a bug report with bugzilla and attach
> your changes we can ask Dave to look at it and integrate it with
> the code base. It sounds like you did an excellent job of
> fixing things.
> ----- Original Message Follows -----
>>I haven't done an update in a week or two, so thought I would update
>>everyone on whats going on.
>>I bought an SB card, but the snd_driver load didn't even see it, so
>>I put the 'white box' special back in. After restarting, I saw lots
>>more action. Started getting wwv3 and 4 messages, but it still would
>>not quite get happy. After an hour or so, it even lost minute sync
>>and did a full restart. Never again did it get any better.
>>On a hunch, opening up the case and voila. Hot. Bad fan.
>>I replace (er, kludge) some fans. Things get better, for a while,
>>and even set the clock once, before getting unhappy. Even days of
>>running with s9+ WWV signals would not fully sync.
>>So, I start wrapping my head around the refclock_wwv driver.
>>was more like it was wrapping itself around _my_ head, but I digress.
>>At least I started understanding the sequence of the debug messages,
>>what to watch for. I even added one myself to watch the watchcat
>>The WWV docs say the 100Hz 1bps data is at 50% modulation. This does
>>not correspond to the source code, so I changed the value of DGAIN
>>from 10 to 2. I varified the levels with a scope. It is 50% of the
>>Seems better, but still not there yet.
>>Today, in frustration, I find another scrapbin audio card. Another
>>that the snd_driver load wouldn't find. :(
>>So, I put the semi-working on back in, rebooted, and I'll be damned.
>>It progressed non-stop from Minute sync (took 2 minutes) directly to
>>second sync. 3 minutes later it had all the digits. After it had
>>seen all the digits with high certainty, it set the clock and stayed
>>there. Total elapsed time about 20 minutes. It then proceeded to ramp
>>up the audio clock freq updates to 1024 and is happy as a lark!!
>>I'm writing this some 5 or 6 hours after the lock. I'm still seeing
>>clockstat output like:
>>53528 14520.008 127.127.36.0 0 2005 158 04:02:00 D -6 0 127 WV15 21
>>5 88.0 1024
>>53528 14522.016 127.127.36.0 wwv5 001f 175 4924 3207/34.4 5678/18.2
>>WV15 fe91 37 3514/40.0 WH15 0002 19 1895/33.3
>>Which is very good. It is starting to take some data hits though.
>>It is starting to fall off compared to a few hours ago. This is
>>Propagation on 15 Mhz is starting to drop off to CO. 10 would be
>>The Traconex receiver is not very agressive at checking better freqs.
>>has to really get weak.
>>Anyway, I'd like to tune the fudgetime value now to match the GPSs,
>>but it probably won't relock. Wish I knew what made it do it today.
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