On Thu, Mar 15, 2012 at 2:51 PM, Attila Kinali att...@kinali.ch wrote:
After the discussion here, i had a similar idea. I want to use the
STM32F4xx for something bigger and bought two discovery boards to get
used to them. But i didn't know what i want to do... it should be something
usefull..
In message Pine.LNX.4.64.1203152001370.3542@tesla, Marek Peca writes:
Yes, it should work on any USB audio capable OS, ie. Linux, Windows, MacOS etc.
I would like to recommend against this approach for a number of reasons.
First, yes, while you can do undersampling and such, it puts very high
On Thu, 15 Mar 2012 22:27:53 +
Poul-Henning Kamp p...@phk.freebsd.dk wrote:
If I, based on my design, were to design a gadget for doing VLF
time-nuts stuff, it would be:
Floating Input trafo with center-tap for powering antenna
16 bit 1MSPS ADC
ARM chip
10MHz clock input
1PPS sync
On Thu, Mar 15, 2012 at 3:13 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message 20120315152620.8347488e049854218aed4...@kinali.ch, Attila Kinali
w
rites:
Do you need 16 bits or can you get by with a 12 bit ADC?
In general: The more the merrier, for a digital dude like me, having
PHK,
I'm interested in your circular averaging buffer: suppose 1K long, the 1st
sample goes into position 0, the 2nd into 1 ... the 1000th into 999 or, the
1st gets scaled and then summed with that already present in position 0
then the result back in position 0? And so on, of course, for position
That would be big expensive filter. All you really need is the
average of the last N samples.
But with WWVB the bits are amplitude modulated at one bit per second.
so you want a big time constant on any AGC, maybe 100 seconds. If
you are sampling at 192K that would use way to much memory if
On 3/15/12 8:10 AM, J. Forster wrote:
Why make it simple when complicated also works?
-John
Can't get your doctorate doing something someone else has already
done...grin
Enormous literature out there on this, and it's been grist for many a
Master's or PhD dissertation.
All in a quest
On 3/15/12 3:24 PM, Chris Albertson wrote:
On Thu, Mar 15, 2012 at 2:51 PM, Attila Kinaliatt...@kinali.ch wrote:
After the discussion here, i had a similar idea. I want to use the
STM32F4xx for something bigger and bought two discovery boards to get
used to them. But i didn't know what i want
On 3/15/12 3:27 PM, Poul-Henning Kamp wrote:
In messagePine.LNX.4.64.1203152001370.3542@tesla, Marek Peca writes:
Yes, it should work on any USB audio capable OS, ie. Linux, Windows, MacOS etc.
I would like to recommend against this approach for a number of reasons.
First, yes, while you
On 3/15/12 9:41 PM, Chris Albertson wrote:
On Thu, Mar 15, 2012 at 8:45 PM, Jim Luxjim...@earthlink.net wrote:
http://dttsp.sourceforge.net/
documentation for dttsp is less than wonderful
Frankly, my dear, I'd rather be a generalist.
-John
On 3/15/12 8:10 AM, J. Forster wrote:
Why make it simple when complicated also works?
-John
Can't get your doctorate doing something someone else has already
done...grin
Enormous literature out there on this, and it's
In message 4f6116ce.7080...@pacific.net, Brooke Clarke writes:
I sure would like a WWVB BPSK receiver for the new modulation.
I've been playing with SDR and VLF signals for ages. What you
want is an antenna, a 1MSPS ADC and a fast-ish CPU.
One very interesting thing you can do with that, is
The first move will be to familiarize with this new modulation format. Of
course I can't receive the WWVB but the DCF77 maybe a good test for me.
On Wed, Mar 14, 2012 at 11:08 PM, Brooke Clarke bro...@pacific.net wrote:
Hi:
I sure would like a WWVB BPSK receiver for the new modulation. The
Dear Time-Nuts,
(new at this list, but reading for long time excellent timekeeping
oscillator articles)
I sure would like a WWVB BPSK receiver for the new modulation. (..)
I'm sure in time there will be plenty of low cost ICs designed to receive the
new signal, but my guess is that many
All very nice, but if this change renders all existing receivers useless.
How does that improve things?
All it does is wipe out all the existing phase tracking infrastructure.
The only benefit is to the government who can reuse the WWVB transmitter
and frequency allocation. Everybody else will
On Wed, Mar 14, 2012 at 3:08 PM, Brooke Clarke bro...@pacific.net wrote:
Hi:
I sure would like a WWVB BPSK receiver for the new modulation. The
processing gains described in the paper John Seamons linked describes
processing gains that are tens of dB above what's possible with the old AM
Asus has a $30 Xonar PCI soundcard that should do the job.
I have two of the the more expensive pci-e versions. Some motherboards
can do a/d at 192 but not as well as the Xonar.
I made a 60 KHz antenna by winding a zillion turns on a ferrite
rod and a padder going into the gate of a FET.
I will share my few bits of worked experience. But it may seem obvious.
I'd say to go 100% SDR. In other words a simple front and that
pushes as much of the functionality into software as possible. The
carrier is only 60K. That is low enough that one can directly
digitize the RF using an
In message Pine.LNX.4.64.1203142345310.2459@tesla, Marek Peca writes:
I will share my few bits of worked experience. But it may seem obvious.
I'd say to go 100% SDR. In other words a simple front and that
pushes as much of the functionality into software as possible. The
carrier is only
Hi John:
They are going to maintain the existing AM modulation format so all the WWVB Atomic Clocks will still work. The phase
modulation is added on top of that.
Yes, I expect my HP 117 may no longer work, but I'd much rather have the
improved s/n and timing accuracy.
Have Fun,
Brooke
Brooke,
As I've said, I don't care about the Time. The time determined by the
start of TV or radio programs is plenty good enough to keep any
appointments.
My only interest is as a standard of Time Interval as a reference for
synthesizers, counters, etc.
If you think about it, unless you are
I am afraid that like John my concern is the frequency reference. Time?
Heck it comes by the internet, WWV or GPS and lastly good old watches that
do pretty well these days. No comments on celphones. So the term is
screwed. All of the sampling and computer processing may indeed loose the
primary
Brooke,
In speaking with John Lowe of NIST (Group Leader for Time Frequency service),
he stated that the absolute time recovery of
their intended new modulation scheme is 10 milliseconds. Nothing stellar there
!
BUT you are right, all of us that have hp-117 type receivers are just out of
OK thats great a maybe pic chip answer. They do cure all ill's after all.
Really scratching my head here. But I do think there is an answer as long
as the phase reversal is accurately controlled and still referenced to the
reference standard.
A I say I need to read.
Regards
Paul
On Wed, Mar 14,
In thinking about it a bit further, one might be able to take the 60 kHz
received sine at some point in the receiver, full wave rectify and HP
filter it (which doubles the frequency) then divide by two in a Flip-Flop
and heavily filter the resultant. This is a hybrid solution... analog and
John
Like your thought. I seem to remember costas loops work like that to
recover the carrier.
Paul,
It recovers a bipolar signal to steer the local VCO as well as the data..
It also needs a quadratue hybrid at the VCO frequency (although it might
be fairly easy to make a quadrature
On 3/14/12 8:07 PM, J. Forster wrote:
John
Like your thought. I seem to remember costas loops work like that to
recover the carrier.
Paul,
It recovers a bipolar signal to steer the local VCO as well as the data..
It also needs a quadratue hybrid at the VCO frequency (although it might
be
On 3/14/12 8:07 PM, J. Forster wrote:
John
Like your thought. I seem to remember costas loops work like that to
recover the carrier.
Paul,
It recovers a bipolar signal to steer the local VCO as well as the
data..
It also needs a quadratue hybrid at the VCO frequency (although it might
Bill wrote:
[BPSK] leaves all the real Timenut type people, actually
using the system for its intended purpose, out in the cold
To be fair to NIST, there really aren't many people using WWVB as a
source of laboratory-grade timing signals. As others have pointed
out, it isn't accurate
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