> As you go deeper you get a delayed history of the surface temperature.
Right. Skin depth.
> A good oven runs rings around deep earth stability.
But a hole in the ground doesn't take any power.
Suppose you had a crystal in a stable temperature environment as part of a
PLL, but the tempera
Hi John,
Thank you for clarifying the openness of the transmission format.
Could I ask whether there is any scenario under which aspects of the
signal transmission design might be patented? If companies or
individuals wish to patent aspects of receiver design, that's fine,
but I'd be uncomfortabl
> I'm not sure about residual carrier aiding the tracking process. A Costas
> loop recovers the carrier pretty well, and a symbol aided loop (where the I
> channel has a hard limiter, for instance) does even better.
Yes, these work (and a soft tanh() limiter improves on the hard
limiter a little
On 9/26/12 9:11 PM, Peter Monta wrote:
Have you actually tried it and gotten it working, except possibly in a
very strong signal area?
This is precisely the issue. Squaring the WWVB signal results in a
significant SNR penalty. At high SNR it doesn't matter that much; at
low SNR you are in a w
> Have you actually tried it and gotten it working, except possibly in a
> very strong signal area?
This is precisely the issue. Squaring the WWVB signal results in a
significant SNR penalty. At high SNR it doesn't matter that much; at
low SNR you are in a world of hurt.
I had suggested to John
The most likely scenario is that XW has a patent pending on technology which
permits the manufacture of a very cheap dependable time-code receiver for
the mass market. Think along the lines of receiver subsystems below $5
(maybe below $1). If there were a market for WWVB timing receivers you wou
I love the inventory / owner tag
Phaxe 1 Incubator
-pete
On Wed, Sep 26, 2012 at 12:02 PM, J. Forster wrote:
> That looks to be an approximate functional equivalent of a Tracor 527E. If
> I didn't have a Tracor, I'd be standing in line.
>
> -John
>
> =
>
>
>> Hi! I've been a lurker
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
On 9/26/12 5:15 PM, Bob Camp wrote:
Hi
Last time I checked, you can build one for your own use and are allowed to use
what ever you want, regardless of it's patent status.
not precisely true..there's some restrictions on that process (e.g. you
can practise an invention in the course of mak
On 9/26/12 4:26 PM, J. Forster wrote:
And would anybody accept the results as accurate?
why not.. the transmit signal specification is published, you could
analytically prove what the receiver performance should be and verify
your implementation against it
We do this all the time with BPSK
I have one of those myself.
I have been looking for a schematic. Does anybody have one?
Better yet, a full manual!
-Brian, WA1ZMS
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Louis Mamakos
Sent: Wednesday, September 26, 2012 2:40
On 09/26/2012 07:13 PM, Tom Van Baak wrote:
For those of you who don't dare click on encrypted Yahoo URL's, the original
NIST link is:
http://www.nist.gov/pml/div688/grp40/upload/NIST-Enhanced-WWVB-Broadcast-Format-sept-2012-Radio-Station-staff.pdf
Burt,
My reading of the document(s) is that
Hi
Last time I checked, you can build one for your own use and are allowed to use
what ever you want, regardless of it's patent status.
Bob
On Sep 26, 2012, at 7:15 PM, Jim Lux wrote:
> On 9/26/12 9:46 AM, J. Forster wrote:
>> I just received this in reply to a query ablot the availability of
I've purchased some VERY cheap ones from eBay (china/hongkong). Some from
Motorola/ Trimble/ etc, Some with SiRF protocol, all with NMEA
protocol. All cheap. :-)
Just read the spec sheet on each before you buy, ...they are often in the
eBay auction, btw.
If it says the 1-pps is 't
And would anybody accept the results as accurate?
-John
==
> On 9/26/12 9:46 AM, J. Forster wrote:
>> I just received this in reply to a query ablot the availability of
>> receiver designs for the new WWVB format:
>
>
>> No sir, the government does not have a receiver design. The desig
What would annoy me is less-than-full disclosure of the transmitted
signal and its properties. For example, there's a claim in the paper
that the (31 26) Hamming code used can detect double-bit errors in the
encoded time.
You are right. The standard Hamming code: detect and correct 1
(3,1)
(7
On 9/26/12 9:46 AM, J. Forster wrote:
I just received this in reply to a query ablot the availability of
receiver designs for the new WWVB format:
No sir, the government does not have a receiver design. The design has
been created by Xtendwave under an SBIR grant. Their design is proprietar
Do not be so sure that a deep hole will give stable temperature.
I measured a nice sinusoid of about 0.3 *C over a year in a cave about 10
metres below the surface.
The attenuation function depends on the thermal diffusivity of the soil/rock,
but that does not vary widely.
As you go deeper you ge
Hmmm SDR. Does that mean spensive darn radio?
Joking aside its clearly massive overkill.
The rf front end is very reasonable and 3-4 stages of opamps like the TL08X
class will do a very fine job and you can even use stages as active
bandpass filters etc. Have built a few over the last 6 months. Its
This has a 1PPS pin (pin 40) - don't know if it is brought out onto the
board but it's there.
https://www.sparkfun.com/products/11058
$50
> -Original Message-
> From: time-nuts-boun...@febo.com
> [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray
> Sent: Wednesday, September 2
There could well be interest on the GenRad Yahoo Group.
-John
=
> I have an old, but looks just like new, General Radio FR46/URM-18
> Frequency
> Calibrator.
>
> It is a rack mount and has a metal container that has inner box that is an
> oven. In the center of the oven is a su
Or pay XW any royalty they demand (Viz Lipitor or Xyvox).
This could well be a high hurdle any other entrants into the marketplace.
-John
=
> With all due respect;
>
> What I dislike is the pre-entry of a company that has direct knowledge of
> the format, tying up the easy (and
On 26 Sep, 2012, at 14:43 , paul swed wrote:
> Might be a bit of a cost. The SDR runs $1495.
> Regards
> Paul
The ones with the clock input options (the SDR-IP
and the NetSDR, I think) are significantly more than
that. But they are also huge overkill if all you want is
a digital LF receiver.
Th
I have an old, but looks just like new, General Radio FR46/URM-18 Frequency
Calibrator.
It is a rack mount and has a metal container that has inner box that is an
oven. In the center of the oven is a suspended quartz block, hung by spring
like devices in all directions. The front panel has a the
Might be a bit of a cost. The SDR runs $1495.
Regards
Paul
On Wed, Sep 26, 2012 at 5:36 PM, Dennis Ferguson <
dennis.c.fergu...@gmail.com> wrote:
>
> On 26 Sep, 2012, at 11:19 , Majdi S. Abbas wrote:
>
> > On Wed, Sep 26, 2012 at 10:13:22AM -0700, Tom Van Baak wrote:
> >> My reading of the docume
On 26 Sep, 2012, at 11:19 , Majdi S. Abbas wrote:
> On Wed, Sep 26, 2012 at 10:13:22AM -0700, Tom Van Baak wrote:
>> My reading of the document(s) is that the new format will in fact allow
>> WWVB to be used as a frequency standard with even greater precision then
>> before, though not with unm
With all due respect;
What I dislike is the pre-entry of a company that has direct knowledge of
the format, tying up the easy (and less expensive) methods of decoding the
time data using prior inside information and the patent system.
Let's say you find out what this PM modulation format is a
Hi
I don't have a problem with going after a known format. What I have been
worried about is the existence of a portion of the format that we simply do
not know about (yet).
Of less concern are the minor details about the actual transmission. For
instance: Added AM modulation (or not) to zero car
If they have FCC ID numbers, you may be able to find photographs of the inside
of the devices, which in turn could reveal the chipset if the photo was clear,
then with the chipset you could determine if a 1 second pulse is available.
Years ago I got a GPS board from Asin or something like that.
Thank you.
On 9/26/2012 2:34 PM, David McGaw wrote:
Hi John,
Thank you very much for the clarification.
Best regards,
David McGaw N1HAC
Dartmouth College
Dept. of Physics and Astronomy
On 9/26/12 2:29 PM, John Lowe wrote:
Dear Time-Nuts Forum,
In an attempt to quiet the discussion that has
Hi John,
Thank you very much for the clarification.
Best regards,
David McGaw N1HAC
Dartmouth College
Dept. of Physics and Astronomy
On 9/26/12 2:29 PM, John Lowe wrote:
Dear Time-Nuts Forum,
In an attempt to quiet the discussion that has started, I will take
the unusual step and address t
d...@montana.com said:
> Have any of the 'nuts hacked one of the very simple very cheap GPS USB
> devices for your car top to see if there is an available 1 sec tick inside
> one of them somewhere?
I took one apart. It had a GPS module with a part number that was easy to
look up on the web. Ye
The pulse per second output on the Garmin serial/CMOS interface units
is only specified to be within 1 microsecond. I guess they are
commonly used to synchronize NTP servers where any extra precision
would be lost in network transport anyway.
I have been thinking of picking one up cheap to test s
albertson.ch...@gmail.com said:
> I figure the thermal mass of many tons of concrete and soil must be, well a
> lot.
The concept you want is skin depth. It's not the thermal mass, it's the
ratio of mass to conductivity.
I haven't found a good web page. This one has a table on page 27. It
de
Have any of the 'nuts hacked one of the very simple very cheap GPS USB
devices for your car top to see if there is an available 1 sec tick
inside one of them somewhere? I have one that I intend to look at, but
I'll have to get a scope and teenyweeny probe outside to do it, so, if
there is a readily
On Wed, Sep 26, 2012 at 11:59 AM, Majdi S. Abbas wrote:
> On Wed, Sep 26, 2012 at 11:38:10AM -0700, Chris Albertson wrote:
>> The first stepis to simply use a regular PC, maybe running Linux.
>> This is the easiest and fastest platform to develop on. It gets
>> harder and takes longer if you use
Keeping a "GPSDWW" buried in a deep hole in ground make me feel like a
graveyard, since the "wrist" should be buried as well...
I'm not sure that even time-nuts need precise time in after-life?
(Sorry, I didn't resist :-) )
Jean-Louis Oneto
Le 26/09/2012 04:48, Chris Albertson a écrit :
On Tue,
That looks to be an approximate functional equivalent of a Tracor 527E. If
I didn't have a Tracor, I'd be standing in line.
-John
=
> Hi! I've been a lurker on time-nuts for some years now, largely because
> of an unhealthy preoccupation with time synchronization with NTP over the
On Wed, Sep 26, 2012 at 11:38:10AM -0700, Chris Albertson wrote:
> The first stepis to simply use a regular PC, maybe running Linux.
> This is the easiest and fastest platform to develop on. It gets
> harder and takes longer if you use a smaller and more esoteric
> platform like a DSP or FPGA. Us
This is a job for Raspberry Pi...
Don
Majdi S. Abbas
> On Wed, Sep 26, 2012 at 10:13:22AM -0700, Tom Van Baak wrote:
>> My reading of the document(s) is that the new format will in fact
>> allow
>> WWVB to be used as a frequency standard with even greater precision
>> then
>> before, though not wi
On Wed, Sep 26, 2012 at 06:05:14PM +, Poul-Henning Kamp wrote:
> Class action suit because they *improve* your VLF time/freq reference
> signal and document the new format ?
Speaking for myself, I'm mostly annoyed that our government was
lobbied with its own money for this*.
Hi! I've been a lurker on time-nuts for some years now, largely because of an
unhealthy preoccupation with time synchronization with NTP over the last couple
of decades.
A buddy of mine is clearing out a bunch of hardware he's accumulated over time,
and has an Austron Model 6016 "Frequency Mul
> DSP would be good, although I also think an microcontroller
> implementation could be interesting. Atmel's ARM MCUs look like they'd
> be good candidates for this sort of thing.
The first stepis to simply use a regular PC, maybe running Linux.
This is the easiest and fastest platform t
Dear Time-Nuts Forum,
In an attempt to quiet the discussion that has started, I will take the
unusual step and address this forum.
NIST is providing full disclosure of the WWVB PM format. There are no
hidden bits or protocols. We will continue to be entirely forthcoming
with the WWVB broad
If the company that developed the format has a lead on tying up the IP for
marketing the new format so that others cannot play, then yes, there is a
problem. Really!
- Original Message -
From: "Poul-Henning Kamp"
To: "Discussion of precise time and frequency measurement"
Sent:
On Wed, Sep 26, 2012 at 10:13:22AM -0700, Tom Van Baak wrote:
> My reading of the document(s) is that the new format will in fact allow
> WWVB to be used as a frequency standard with even greater precision then
> before, though not with unmodified legacy WWVB carrier receivers. My hope
> is that
In message <50633bf8.9050...@ussc.com>, Clint Turner writes:
>In reviewing the NIST document, I don't see anything particularly
>difficult about the new format - either in terms of extracting the time
>or phase/frequency information from the transmissions.
As a somewhat seasoned VLF SDR radio-
Two comments:
First is a matter of principle... the 'upgrade' was done with public
money, taxpayer money. We bought and paid for it. It should be freely
available. Xtendwave is essentially taxing a public service.
If Xtendwave wants a monopoly on time, they should build their own
transmitter, ra
Paul, I have a couple of Spectracoms running and have pretty decent WWVB
signal strength here. I'd be happy to test the hack.
John
On 9/26/2012 1:32 PM, paul swed wrote:
I may have at least the spectracoms figured out. Its a hack and at least
using my homebrew wwvb psk encoder seems to w
On 26 Sep, 2012, at 10:03 , J. Forster wrote:
> You go after everything. Soup to nuts, including the contract agreements.
>
> IMO, this is potentially very, very big money, because Xtendwave may also
> have patent protection, and henceforth control all the precise digital
> clock market. This is
I may have at least the spectracoms figured out. Its a hack and at least
using my homebrew wwvb psk encoder seems to work. But its not a general
purpose design. It will work with the fluke 207 and HP 117s but you have to
have a base spectracom to hack.
Technically speaking unattractive.
But that sa
In reviewing the NIST document, I don't see anything particularly
difficult about the new format - either in terms of extracting the time
or phase/frequency information from the transmissions. With
undersampling, carrier recovery (to determine phase and amplitude
information) should be do-able
Tom,
Thanks you for that file. Somehow I missed it. I think the real
answer to my question is for the FCC to add GPS to their accepted
standards for Frequency Measurements in the broadcast related rules.
Thanks,
Burt
From: "Tom Miller"
Subject: Re: [time-nuts] New WWVB format...
See
For those of you who don't dare click on encrypted Yahoo URL's, the original
NIST link is:
http://www.nist.gov/pml/div688/grp40/upload/NIST-Enhanced-WWVB-Broadcast-Format-sept-2012-Radio-Station-staff.pdf
Burt,
My reading of the document(s) is that the new format will in fact allow WWVB to
be
You go after everything. Soup to nuts, including the contract agreements.
IMO, this is potentially very, very big money, because Xtendwave may also
have patent protection, and henceforth control all the precise digital
clock market. This is tens of millions of units, at least.
-John
Better yet, it's election season. Anybody feel like researching the
management of Xtendwave and their political connections?
-John
===
> Class action suit anyone?
>
> - Original Message -
> From: "J. Forster"
> To:
> Sent: Wednesday, September 26, 2012 12:46 PM
> Subject:
Hi
I still think the original idea about a FOA filing is a *very* good one.
Don't go after the receiver. Go after all the details about the transmit
format.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Tom Miller
Sent: Wednesday
Class action suit anyone?
- Original Message -
From: "J. Forster"
To:
Sent: Wednesday, September 26, 2012 12:46 PM
Subject: [time-nuts] WWVB Now a Monopoly
I just received this in reply to a query ablot the availability of
receiver designs for the new WWVB format:
-
Hi
At least from here, that link appears to be broken. If it's the same details
as on the NIST web site, they are already part of a thread here.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Burt I. Weiner
Sent: Wednesday, Septem
You have not answered my question. Yes or no, do you have it working on
the new WWVB format?
-John
=
> Hi
>
> The issue is dithering the input to the ADC. If you filter "to much" you
> get
> to the point that you are not dithering very much. That actually reduces
> the
> lineari
Hi
Yup, SBIR fund the monopoly and we switch around WWVB for them for free...
That said, it's not a very hard format to work with *provided* you get the
details of what they are transmitting. There's still the "further details to
be published in the first part of 2013".
Bob
-Original Messag
Hi
The issue is dithering the input to the ADC. If you filter "to much" you get
to the point that you are not dithering very much. That actually reduces the
linearity of many ADC's (ie spurs go up). It very much impacts your ability
to pull out low level signals.
Done that? yes lots of times. Go
I just received this in reply to a query ablot the availability of
receiver designs for the new WWVB format:
Original Message
Subject: Re: WWVB Protocol Notification
From:"John Lowe"
Date:Wed, September 26, 2012 9:13 am
To: "j
See:
http://www.nist.gov/calibrations/upload/1424.pdf
Re. GPS traceable to NIST.
- Original Message -
From: "Burt I. Weiner"
To:
Sent: Wednesday, September 26, 2012 11:49 AM
Subject: [time-nuts] New WWVB format...
I'm sure most of this group has seen the information put out by NI
I'm sure most of this group has seen the information put out by NIST
regarding the changes to the WWVB format. But, for those who may not
yet have seen this, here's a link to it:
http://f1.grp.yahoofs.com/v1/cBhjUH41xVccWM9P8EU4JqzmFNevFgDUFkRcgfLyry1Rn3HqMV5iDqYDgsd2pM1-Vq3nhF9WERTjVF_WmRjAez
That article is still alive:
www.tinaja.com/glib/WWVBexps.pdf
From: David McGaw
To: Discussion of precise time and frequency measurement
Sent: Wed, September 26, 2012 10:58:00 AM
Subject: Re: [time-nuts] WWVB PM Receiver
It's not a commercial unit. As it s
Hi Ulrich;
I just used a pin removeal tool and made that slave DB9 match straight through.
Best Wishes;
Thomas Knox
> From: df...@ulrich-bangert.de
> To: time-nuts@febo.com
> Date: Wed, 26 Sep 2012 11:07:50 +0200
> Subject: Re: [time-nuts] Question on OSA8600 Oscillators
>
> Tom,
>
> many tha
It's not a commercial unit. As it says at
[1]http://www.maxmcarter.com/rubidium/index.php, " Almost 30 years ago,
I built a receiver for WWVB roughly based on a Don Lancaster design."
Apparently this refers to an old article, " Don Lancaster,
Experimenting with WWVB, Radio Electroni
Thats what I was reading. But have to say I have never seen a commercial
divider chain that could be changed. The spectracoms divide to 20 Khz and
mult by 3. So would like to see that circuit.
Regards
Paul
On Wed, Sep 26, 2012 at 10:00 AM, David McGaw wrote:
> As I read it, the feedback divider w
As I read it, the feedback divider was reprogrammed.
David
On 9/26/12 9:49 AM, paul swed wrote:
Also curious on the rcvrs doubling to 120 KHz another multiplier or did the
rcvr happen to have a way to change that frequency? The note says that the
rcvr local carrier doubled.
Regards
Paul
On We
Also curious on the rcvrs doubling to 120 KHz another multiplier or did the
rcvr happen to have a way to change that frequency? The note says that the
rcvr local carrier doubled.
Regards
Paul
On Wed, Sep 26, 2012 at 9:18 AM, J. Forster wrote:
> Have you actually tried it and gotten it working, e
Have you actually tried it and gotten it working, except possibly in a
very strong signal area?
-John
> Hi,
>
> From: "Bob Camp"
>
>> A tuned antenna probably is going to provide all the selectivity you'd
>> need.
> Another possibility is to modify your old circuit like that:
Hi,
From: "Bob Camp"
A tuned antenna probably is going to provide all the selectivity you'd need.
Another possibility is to modify your old circuit like that:
http://www.maxmcarter.com/rubidium/2012_mod/index.html
Bye,
Jean-Louis
___
time-nuts mai
Tom,
many thanks! This is enough info. I will open the box and connect to the
"original" plate. Had no idea that it is something like these Russian
puppets.
Best regards
Ulrich Bangert
> -Ursprungliche Nachricht-
> Von: time-nuts-boun...@febo.com
> [mailto:time-nuts-boun...@febo.com] Im
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