[time-nuts] PTTI 2012, part 3/3
paulswedb at gmail.com
Thu Dec 6 17:02:00 UTC 2012
Great comments and a good read. OK so what does the drop in replacement
Thanks lots to read here.
On Thu, Dec 6, 2012 at 10:24 AM, Tom Van Baak <tvb at leapsecond.com> wrote:
> > Still, there are always a number of talks of more general interest to us
> time nuts.
> > In the next few postings I'll give more details on a couple of topics:
> And here's the third part of my PTTI report...
> - Vendor presentations/Symmetricom/Miles
> Besides 3 days of presentations, PTTI also hosts a vendor/exhibit area.
> This includes the usual T&F suspects like FEI, Symmetricom, TRAK,
> Spectracom, SpectraDynamics, TimeTech, etc. Most of this gear is outside
> the budget of a regular time-nut but it's always nice to see and touch
> what's on display, knowing in ten years it will show up on eBay.
> Yes, that was John Miles in the Symmetricom booth showing off his, I mean,
> their new TimePod and wearing a Symmetricom shirt. We've had a number of
> time nut "graduates" over the years: Rick Hambly went on to start CNS
> Systems, Said Jackson started Jackson Labs, John Miles became Miles LLC and
> both have ties with Symmetricom. You'll see press releases like this one:
> If you have more questions, I'm sure John will be happy to answer then on-
> or off- the list.
> - M12/uBlox GPS board
> It was very nice to see Tom Clark ("grandfather" of time-nuts) at PTTI; it
> was from his work at NASA with VLBI, masers, and Motorola Oncore GPS
> receivers that a number of us caught the precise time bug in the early 90's.
> Many of you know him as the author of the often recommended paper
> "Critical Evaluation of the Motorola M12+ GPS Timing Receiver vs. the
> Master Clock at the United States Naval Observatory, Washington DC" which
> is available here:
> Anyway, this year Tom Clark presented performance results of a new GPS
> board. It is h/w and s/w compatible with the Motorola M12 receiver used in
> many existing T&F products, but it's based on a uBlox-6T chip instead of
> the Motorola or iLotus M12 chip. The trick is that Rick Hambly added a PIC
> on the board to make it talk exactly like an M12. The reason for this is to
> allow drop-in replacement of the original Motorola M12 or still-current
> iLotus M12+ with this new one. It's called the Synergy SSR-6T.
> That means that any instrument (e.g., GPSDO) that uses an M12 can be
> upgraded to the uBlox-6T. Tom's presentation contains charts showing the
> performance improvement:
> I have one to play with and hope to duplicate his results. I didn't get
> pricing/availability info but it is supposed to be "really cheap". (Tom
> Clark -- can you provide this info when you get it?)
> - Quartz in space
> With all the focus on fiber and optical and atomic clocks, it's refreshing
> to hear now and then about good old quartz. This was a fascinating talk
> about real-world (or real out-of-this-world) performance of quartz
> oscillators in space. What they did was mine recorded telemetry from many
> space missions looking to directly/indirectly measure the frequency of the
> quartz oscillator over years in space.
> Just like we use LH to monitor the EFC of a GPSDO, they monitor the EFC of
> the quartz LO in the GPS sats. In addition to normal drift there are
> effects of radiation dose and solar flares. I'll post the URL of the paper
> when it's out. Meanwhile I saw a bunch of fine papers/presentations at the
> FEI site:
> - ION/PTTI 2013 in Bellevue, WA (!)
> After 44 years, PTTI is changing "management". Instead of being organized
> by the US government (USNO, NASA, JPL, and DoD) it will now be run by ION
> (Institute of Navigation). This keeps the government out of the hospitality
> and conference business.
> The next ION/PTTI will be held in Bellevue, WA. If you haven't considered
> attending an ION or PTTI conference before, this might be a good one to
> try. Also, since that's my hometown, I plan to have an "open house" during
> the conference. That means I have a year to clean up the lab so more than
> one person can walk in it...
> A number of people continued to comment on the relativity experiment I did
> a few years ago. I have now posted the original (190 page) power-point
> presentation I gave at PTTI that year:
> - The state of Time-Nuts
> Lastly, I wanted to make a note about time-nuts. I was pleasantly
> surprised how many professionals already know about the time-nuts list or
> lurk here. This group has really done well. Perhaps propelled by advances
> in the telecom/optical world or neutrino experiments, there's a whole new
> crop of scientists in the precise time field. Formal technical journal
> articles by PhD's tend not to deal with the mundane details of precise time
> measurement and lab equipment so people turn to google, and find us here.
> As the list grows we face some issues about posting bandwidth, focus, and
> repetition. The list is mostly unmoderated, so it's completely up to you to
> keep the list relevant and interesting. Please resist too off-topic posts
> or low-content postings. For now at least, the archived list is rich enough
> that it acts like a wiki or faq.
> As usual, if you have suggestions on how to make the list better please
> send them to me (tvb at LeapSecond.com) and John (jra at febo.com).
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