On Sun, Jul 08, 2012 at 09:02:53PM -0400, Bob Camp wrote:
> Hi
>
> The gotcha is that they may change the sync word based on test data.
> They may also tweak other vague points in the spec based on the troubles
> they run into in their tests or with their silicon.
I finally read the wwv
Could not the phase modulation be made +/-90 degrees, with the appropriate
number of stuff bits being added so that the average phase remains constant?
Would the older receivers simply average out the phase variation over a
longer period?
David GM8ARV
--
SatSignal Software - Quality software w
There is not an infinity of good sync words. A typical good sync word has
a high positive autocorrelation when synced, sloping downwards
monotonically.
Thus the cross-correlation of the received word with a locally stored
reference can be used to steer the loop using a small dither and a lock-in
t
If you have a deep fade every few hours or minutes, as is common, relock
time becomes an issue.
-John
==
> Hi
>
> The clocks we would be using are *much* better than what most military
> systems use
.
>
> I also *assume* that an initial lock up that takes a hour is perfectly
> accep
Hi
The gotcha is that they may change the sync word based on test data. They may
also tweak other vague points in the spec based on the troubles they run into
in their tests or with their silicon.
Bob
On Jul 8, 2012, at 8:07 PM, Magnus Danielson wrote:
> On 07/09/2012 12:46 AM, paul wrote:
>
Hi
The clocks we would be using are *much* better than what most military systems
use….
I also *assume* that an initial lock up that takes a hour is perfectly
acceptable in this application. You will still need a lot of hours / days /
what ever of data to get useful stability off of WWVB, spen
>"Ei
>Sorry if I have your name reversed. By taking this approach it
>eliminates the ability to use wwvb as a frequency reference because it
>destroys that traceability.
>Thats what we are trying to preserve. Or at least re-establish for the
>older phase measuring receivers.
>Regards
>Paul"
Are yo
On 07/09/2012 12:46 AM, paul wrote:
Peter indeed there could be
But it should not need to be decoded to undo the psk.
Plus documentation lacks some of the details I think to actually do it.
But that would be a significant project since the formats not been
settled completely yet.
I have looked
A risky assumption, and a cold start could be tricky.
Equatorial took many minutes to lock up, with a much higher data rate, and
it did it by slowly sweeping the local clock.
Aside: That's why military spread spectrum systems like good local clocks.
They lock up a whole lot faster that way.
-Joh
Hi
In this case the data format and it's contents are highly "computable". If you
have a good local clock *and* an initial lock, the rest of what follows is
predictable. That of course assumes we know the real format ….
Bob
On Jul 8, 2012, at 6:58 PM, J. Forster wrote:
> Hi Peter,
>
> That's
Hi Peter,
That's be the hard way, but yes, if the message BPSK coded is computable
and of a known format. If the message contained more than time, like solar
flux, it gets more complicated very rapidly.
A similar thing was done with the Equatorial system 30+ years ago. In that
case, each data bit
Peter indeed there could be
But it should not need to be decoded to undo the psk.
Plus documentation lacks some of the details I think to actually do it.
But that would be a significant project since the formats not been
settled completely yet.
Regards
Paul.
On 7/8/2012 6:40 PM, Peter Gottlie
Any possibility of using the decoded signal to un-do the modulation and
feed the reconstituted signal to the older receiver?
On 7/8/2012 12:56 PM, paul wrote:
Ei
Sorry if I have your name reversed. By taking this approach it
eliminates the ability to use wwvb as a frequency reference because
They lie anyway.
Hope you get your power back and not lose it again tonight.
Regards,
Tom
- Original Message -
From: "Brian, WA1ZMS"
To: "Time-Nuts"
Sent: Sunday, July 08, 2012 4:50 PM
Subject: [time-nuts] [OT]: HP-5061A and a dust bunny.
BTW….All 3 cats have been interviewed
I understand this event perfectly. Our feline owners leave us presents on an
occasional basis. Usually we find them straight away, but when we can't, ninja
nose wife takes over.
For some reason, however, they tend to only leave the back half of the dead
rabbit. My spouse says it is because the
This was such a crazy event that I have to share this with somebody.
I started to notice an odd smell in the ham shack/lab yesterday night.
Now we had a bad weather storm and was one of 2.5 Million homes
without AC power for 5 days. So the generators were pressed into
service and kept the l
Ei
Sorry if I have your name reversed. By taking this approach it
eliminates the ability to use wwvb as a frequency reference because it
destroys that traceability.
Thats what we are trying to preserve. Or at least re-establish for the
older phase measuring receivers.
Regards
Paul
On 7/8/2012
If the changeover you are talking about is this one:
http://www.nist.gov/pml/newsletter/radio.cfm as a proof of concept a DVB-T
dongle/upconverter combo could almost certainly handle PM easily to output
whatever it encodes, when paired with gnuradio..
The RTL2832U chip might also be able to handl
>> Further maybe even obtain better performance. But thats far from my
>> concern right now. I simply want to get the systems back online to watch
>> propagation behaviors as I have for years.
>
(DVB-T dongles could excel at that.. automated digitally tuned reception..)
> I don't see how. The time
IMO, a better way to provide the service would be to just turn a couple of
LORAN-C stations back on.
But that would be a tacit admission of another stupid government screwup.
This WWVB scheme can possibly be spun as an 'improvement'- hence
politically less distasteful, even if more expensive for
Hi
I'd bet at least a cold order of fries that what ever chip comes out of this is
going to be a cheap one. At least that will be true after a couple years. The
target market is wall clocks…
Bob
On Jul 8, 2012, at 10:29 AM, paul wrote:
> To be very clear here.
> There is not a box coming from
Demian Martin schrieb:
>If you don't want a delta sigma ADC you can substitute a different
kind >but
>there will be tradeouts. Usually bit depth vs sample rate vs. accuracy.
Any market overview available?
A simple way to discipline a 22.5792 and a 24.576 VCXO to a 10 MHz reference
would be
To be very clear here.
There is not a box coming from NIST.
They do not want the responsibility to maintain what ever it would be.
The reason to make the change to the format is for better frequency and
time distribution by this channel.
It seeks to improve overall system gain and attempts to ne
Here the modified VHDL with the 48KHz and 96KHz clock out:
LIBRARY IEEE;
USE IEEE.std_logic_1164.ALL;
USE IEEE.std_logic_unsigned.ALL;
ENTITY FRSync IS
PORT (ClkIN, RefIN: IN std_logic; -- ClkIN is 24.576MHz/1536->16KHz, RefIN
is 10MHz/625->16KHz
PWMOut, F48KHz, F96KHz: OUT std_logic);
END ENTITY
Hi
On Jul 8, 2012, at 1:17 AM, David J Taylor wrote:
> As an observer from across the pond:
>
> - presumably, the vast majority of users would not be affected.
Yes, the wall clock and wrist watch people (I use both) would not be impacted
according to NIST. I have seen no reports of, and not o
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