[time-nuts] WWVB Now a Monopoly

[Bob Camp]

Hi

It turns out that what *should* be locked isn't always indeed locked.
Symmetricom made a bunch of boxes based on CDMA locking. They found out
about the nasty details after the fact. Made for a great bunch of stuff on
eBay though...

Bob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of bg at lysator.liu.se
Sent: Friday, September 28, 2012 1:38 AM
To: jfor at quikus.com; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Now a Monopoly

Dont you have GPS/Cs locked cell networks anymore in the US?

http://www.endruntechnologies.com/cdma.htm

--

    Björn

> In the real world, if GPS does not work, the WWVB change means you either
> have to buy the XW stuff or go do something else.
>
> YMMV
>
> -John
>
> =================
>
>
>
>> On 9/26/12 7:11 PM, J. Forster wrote:
>>> But if someone here designed and built a $100 receiver and offered it
>>> to
>>> the group, that could well violate some of their IP.
>>>
>>> As to building a home brew receiver and certifying a onsie so your
>>> lab's
>>> cal is traceable, I'd certainly not trust a cal done that way.
>>>
>>> Doing spacecraft communications is hardly the same thing.
>>>
>>
>>
>>
>> Well..if you're trying to do NIST traceable cals in a legally acceptable
>> way, then it's very unlikely that any homebuilt receiver that infringed
>> the patent would be acceptable, from a patent standpoint. The general
>> exemption to practice the invention is for development of a new
>> invention, not to make use of it for other reasons (otherwise, the
>> patent wouldn't be particularly useful in terms of exclusivity).
>>
>> OTOH, if you cobble up a (non-infringing) receiver and validate its
>> performance analytically, why wouldn't that be acceptable for a
>> traceable calibration.  It's no different than using a homebuilt quartz
>> oscillator as a transfer standard, is it?
>>
>> Now, if you're selling calibration services, it would be a tougher sell
>> to your customers: they'd have to believe in your analysis or oscillator
>> building. This is in the sense that if I use a HP 105, the long history
>> and tradition of HP is essentially standing behind the design and the
>> published performance standards; a homebuilt standard has a higher bar
>> for the great unwashed public.
>>
>> If you want traceability for, say, a journal article, then I think the
>> bar is set differently.  For state of the art stuff, the article usually
>> describes the calibration approach, and it's up to the reader to decide
>> if you did it adequately.
>>
>>
>>
>>
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>
>
>
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