-boun...@febo.com] On
Behalf Of Jim Lux
Sent: 27 September 2012 18:26
To: time-nuts@febo.com
Subject: Re: [time-nuts] WWVB PM Receiver
On 9/27/12 7:23 AM, J. Forster wrote:
Jim,
What you are suggesting is essentially a spread spectrum system where the
chip pattern is time varient.
IMO
I am feeling a bit slow here.
There is a carrier always. Thats how the AM works. So somehow we are
speaking about a semi non coherent carrier perhaps??
So whats the nickle solution and it is not squaring in a low s/n
environment. Been there done that. Very bad results on the east coast.
Regards
On 9/26/12 10:15 PM, Peter Monta wrote:
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
Moin,
On Thu, 27 Sep 2012 08:53:03 -0400
paul swed paulsw...@gmail.com wrote:
I am feeling a bit slow here.
There is a carrier always. Thats how the AM works. So somehow we are
speaking about a semi non coherent carrier perhaps??
So whats the nickle solution and it is not squaring in a low
Why not DCF. NIH. Just joking.
Good comments that are detailed. The phase does not change every second
though it can.
There are many times when the phase sits for 3 or more seconds. The PLL TC
is about 2-3 seconds on the older receivers so they tend to jump around
never really locking or only for
Jim,
What you are suggesting is essentially a spread spectrum system where the
chip pattern is time varient.
IMO, this is an incredible kludge. And, there is no gurantee that the
algorythm for generating the chip pattern will not change down the road.
YMMV,
-John
==
On
Hello All -
I am new to this forum but have read it for a couple of years. The
present fulminations on the WWVB format change should be reconsidered
in the light of prior art. As an old RfFengineer I do not see any issue
with the format and the business about patents is not really applicable
as
John
Like your thoughts and have exactly tried all that you say over the last 6
months. The div / 2 is a big issue because of the fades and noise. It
really does not work. Now if you are in the 1000uv contour it most likely
mostly will.
By the way limiting was a nightmare.
Regards
Paul.
On Thu,
Been tried. Doewn't work. Among other things, if you multiply by 2 and
then divide by two, you can have extra flips or missed flips. A Miller
Divider has the same issue.
..
Interesting that you should bring up TV.
A REQUIREMENT of the conversion from BW to color was compatability with
johncr...@aol.com said:
So it should be possible to implement a receiver without infringing any
patents and without reams of signal processing code.
How well would your scheme work with poor signal/noise?
Some of us consider reams of signal processing code to be as much fun as
wiring up
On 9/27/12 7:23 AM, J. Forster wrote:
Jim,
What you are suggesting is essentially a spread spectrum system where the
chip pattern is time varient.
IMO, this is an incredible kludge. And, there is no gurantee that the
algorythm for generating the chip pattern will not change down the road.
In message bc97e391-7abe-413d-868a-1878a2e3a...@rtty.us, Bob Camp writes:
Given the low frequency, it's not to hard or expensive to do a DSP radio. A
true FPGA (not a CPLD) would do it pretty easily. You could probably do it
with a reasonably fast micro controller. Normally the ADC would be a
Hi,
From: Bob Camp li...@rtty.us
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
___
Have you actually tried it and gotten it working, except possibly in a
very strong signal area?
-John
Hi,
From: Bob Camp li...@rtty.us
A tuned antenna probably is going to provide all the selectivity you'd
need.
Another possibility is to modify your old circuit like
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 j...@quikus.com wrote:
Have you actually tried it and
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
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 n1...@alum.dartmouth.orgwrote:
As I read
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
That article is still alive:
www.tinaja.com/glib/WWVBexps.pdf
From: David McGaw n1...@alum.dartmouth.org
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Wed, September 26, 2012 10:58:00 AM
Subject: Re: [time-nuts] WWVB PM
: [time-nuts] WWVB PM Receiver
Have you actually tried it and gotten it working, except possibly in a
very strong signal area?
-John
Hi,
From: Bob Camp li...@rtty.us
A tuned antenna probably is going to provide all the selectivity you'd
need.
Another possibility
...@febo.com] On
Behalf Of J. Forster
Sent: Wednesday, September 26, 2012 9:18 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB PM Receiver
Have you actually tried it and gotten it working, except possibly in a
very strong signal area?
-John
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
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
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
Hi:
So how do we make a receiver to decode the PM format?
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
J. Forster wrote:
Original Message
Subject: WWVB Protocol Notification
From:
File an FOIA request?
-John
==
Hi:
So how do we make a receiver to decode the PM format?
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
J. Forster wrote:
Original Message
Hi
Given the low frequency, it's not to hard or expensive to do a DSP radio. A
true FPGA (not a CPLD) would do it pretty easily. You could probably do it with
a reasonably fast micro controller. Normally the ADC would be a significant
chunk of the cost. At 60 KHz … not so much.
Bob
On Sep
Brooke
There is indeed additional detail in the spec that we had not seen. So I
will do some reading tonight.
However I am still working on the d-psk-r and at least at this point may
have a mod that works. It does on my local home brew bpsk generator even
when I add a great deal of noise. Though
I'm actually not joking about an FOIA. It would probably be worth asking
John Lowe for the design and code first though.
YMMV,
-John
=
Brooke
There is indeed additional detail in the spec that we had not seen. So I
will do some reading tonight.
However I am still working on the
On Tue, Sep 25, 2012 at 2:18 PM, Brooke Clarke bro...@pacific.net wrote:
Hi:
So how do we make a receiver to decode the PM format?
With a transmit freq so low you could directly sample the RF with a
not-very-fast A/D converter.However I'd want some selectivity in the
front end before
On Tue, Sep 25, 2012 at 06:15:06PM -0400, paul swed wrote:
But like you I am curious is there a chip set that does the magic available
from DigiKey for $3.95? Would hope that what ever comes out might have a
phase control signal. Or does this cost an arm and a leg?
Paul,
Hi
As long as you deal with straight overload, an ADC based receiver doesn't need
as much front end selectivity as you might think. A fairly simple L/C filter
should be plenty. A tuned antenna probably is going to provide all the
selectivity you'd need.
Bob
On Sep 25, 2012, at 6:44 PM,
I have had a neat little WWVB receiver hanging around the lab that was made by
a now defunct company called Elemek out of East Syracuse, New York. It was
manufactured in 1979 and consists of a handful of discrete components for the
RF front end followed by simple CMOS logic and a few analog op
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