If I could suggest a shorter and perhaps simpler solution. Rather than
reinventing the wheel, simply insert each value as read into a SQL database
engine, there are numerous free ones available, i.e. MySQL or Postgresql. You
could include a timestamp either with your code or the system can do
On Sat, 26 Mar 2011 17:48:12 -0700
Hal Murray wrote:
> Does anybody have any ideas on how much better you could do with an ADC and
> DSP?
There are many. From simple high-tap filters to sofisticated methods
like maximum likelyhood decoders.
The field is vast and quite well worked on. The book
for i/o with simple tools built-in.
> Check it out.
> Don
>
> - Original Message - From: "paul swed"
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Tuesday, March 29, 2011 7:57 AM
> Subject: Re:
ency measurement"
Sent: Tuesday, March 29, 2011 7:57 AM
Subject: Re: [time-nuts] WWVB Measurements using DSP recovery
Now you see I like these up to date solutions with cheap components. I
recently home brewed "YAGPSDO" yet another GPSDO, just to see how its
done.
When I loo
In message , paul
swed writes:
>I have read the high level comments. But can we get deeper detail. Can it be
>done lets say in basic language etc. The comment I read that struck a cord
>was that all you did was sample and put the information in roughly 1000
>bins. Then I assume look for the bin w
Chris Albertson wrote:
On Tue, Mar 29, 2011 at 7:13 AM, J. Forster wrote:
Even if you can build a perfect receiver I don't see how you can get
around the variable path length issue short of averaging WWVB for days or
weeks.
Yes but you only have to wait once as long as you don't turn
On Tue, Mar 29, 2011 at 7:13 AM, J. Forster wrote:
> Even if you can build a perfect receiver I don't see how you can get
> around the variable path length issue short of averaging WWVB for days or
> weeks.
Yes but you only have to wait once as long as you don't turn it off.
This is OK if the use
That is pretty much the way that it has always been done.
I just assumed that that was a given.
Greg
On 3/29/2011 8:13 AM, J. Forster wrote:
Even if you can build a perfect receiver I don't see how you can get
around the variable path length issue short of averaging WWVB for days or
weeks.
-
Even if you can build a perfect receiver I don't see how you can get
around the variable path length issue short of averaging WWVB for days or
weeks.
-John
> Now you see I like these up to date solutions with cheap components. I
> recently home brewed "YAGPSDO" yet another GPS
Now you see I like these up to date solutions with cheap components. I
recently home brewed "YAGPSDO" yet another GPSDO, just to see how its done.
When I look at things like a frontend and maybe a mixer thats easy stuff.
Even adding a nice A/D converter etc is easy if you can solder the darn
thin
In message <4d9129d8.4060...@comcast.net>, Greg Broburg writes:
>Can you show a circuit of what you have done?
Basically I have a 20MSPS PCI card in a PC and do it all in
software.
I did use similar principles to implement a LORAN-C receiver
in a aduc7216 (http://phk.freebsd.dk/AducLoran/) but t
Yes, your idea is very nice.
So, many basement engineers have not moved
into the world of programmable DSP concepts, missing
some basic breadboard circuit and some example
demonstration software to try out. Perhaps your idea
would be the perfect tool to inspire and learn from. The
general nature
In message <4d90b859.2080...@comcast.net>, Greg Broburg writes:
>There is a method to recover a very weak signal
>out of the mud that is fairly easy to build.
I did this slightly differently:
Take a 1MSPS ADC and average it into 1000 buckets in round
robin form, one after the other.
This can b
There is a method to recover a very weak signal
out of the mud that is fairly easy to build. It uses
a multiplying DAC run by a local reference look
up table that is phase locked into the noise. BW
can be effectively 1 Hz. Output of the DAC would
be integrated to a DC value to control the LO.
Onc
Living in Miami probably as far away as possible in the continental US I
have no problem receiving WWVB. When I moved here in 1993, 60 KHz was my main
reference source. I used a Tracor 599 and a HP 117 along with a 4 foot
commercial loop. The 599 showed clearly superior performance. Later Aus
> Pretty much before all these switching power supplies and cpfls etc.
Does anybody know what frequency CPFLs are using today?
I remember that we had some (non-compact) ceiling fluorescents at work with
"electronic" ballasts that were in the 50-60 KHz range. That was 5 years ago.
I wonder if
Chris,
The beginning of the second, and the starting of the 10ms samples is
detected with a tight asm loop. (Soon to be replaced with a high
priority interrupt line) Once detected the sample portion of the
state machine runs at 10ms. And terminates at the 990ms (99th sample),
I process the receiv
Indeed those posts are from 2003 the car plant could be closed these days.
But I do indeed receive wwvb I think pretty well with a loop and preamp. Its
always been a challenge on the east coast and even Michigan when I first
started tinkering way to many years ago.
Pretty much before all these swit
bro...@pacific.net said:
> John Mills (THE NTP guru) has written a number of papers on and built
> examples of a matched filter type receiver for the HF station WWV, but the
> ideas would also be applicable to a WWVB receiver. The performance he gets
> from WWV would knock your socks off so I e
Hi Lenny:
The CMMR-60P is an analog circuit designed for very low power
consumption. That translates to very high impedance circuitry.
I've been playing with them for years. When I first tried them the
reception was not 24/7, but rather mainly centered around local
midnight, but the current
On Sat, Mar 26, 2011 at 4:31 PM, Lenny Story wrote:
> Chris,
> My design isn't really that sophisticated hardware wise. Its an 8051
> variant, and the CMMR-60P which can be obtained from Sparkfun.com. I do
> wind my own antenna, which is just a quad, made from PVC and a metal
> electrical box. T
results when done. Now I think I'll go back to
hiding in the weeds.
73, Doug.
Date: Sat, 26 Mar 2011 18:53:30 -0700 (PDT)
From: "J. Forster"
To: "Discussion of precise time and frequency measurement"
Subject: Re: [ti
From what I remember of the ancient days of watching
WWV against our in house reference, we had a circular
paper plotter (1 revolution per 24 hours) set up and
could observe the daily drift in and out. From what
I remember the story was that it was an observation
of the rise and fall of the E laye
All,
Actually i don't mind all the chatter, gives me more information regarding
all of the topic really.
Been interested in time, on a social level since military school, where
"clock drift" was my #1 excuse for being late to class. :)
73
-Lenny Story
N1YEZ
On Sat, Mar 26, 2011 at 10:36 PM, p
Actually from what I have seen John it is indeed pretty large and does jump
for many reasons. The sun maybe wx. But when you think about the local
oscillator and that is pretty stable and not jumping. Then over time the
phase of wwvb should come back to a predetermined position or lots of
measured
Paul,
I did that years ago in a qualitative way.
I used a local reference of an HP 105B and the 117A w/ HP loop. I synced a
Tek 7854 to the local standard and watched and averaged the recovered 60
KHz. I no longer remember the results well, but sometimes the "seeing" was
<1uS P-P and on other day
Interesting thread and welcome to time-nuts.
Well I suppose since LORAN C has been shut down and I have to say not having
a lot of luck with LORAN from Europe I have dusted off the ole WWVB
receivers. Actually they have been a live a long time. Just spoiled by LORAN
and GPS..
My actual interest is
All,
I think you may be right. Although i did read somewhere that this design was
originally just a technical example of an ATMEL 8-bit DSP ... not sure
though.
-Lenny
On Sat, Mar 26, 2011 at 8:48 PM, Hal Murray wrote:
>
> le...@codematic.com said:
> > As i stated earlier, i'm using a CMMR-60p
le...@codematic.com said:
> As i stated earlier, i'm using a CMMR-60p, which seems to just be a small
> DSP.
The data sheet at SparkFun shows that it's just an analog receiver with a
peak detector and AGC.
Does anybody have any ideas on how much better you could do with an ADC and
DSP?
--
T
Chris,
Regarding the decoding method.
As i stated earlier, i'm using a CMMR-60p, which seems to just be a small
DSP. If i am remotely successful at my current version, my thoughts are
that i would replace the CMMR with a similar DSP, and just FFT the crap out
of the signal at 60khz... but i have
John,
I am hoping that those iono changes aren't going to be fast enough (< 10
sec) to affect my decoding.
-Lenny
On Sat, Mar 26, 2011 at 6:58 PM, J. Forster wrote:
> I used to use WWVB before LORAN came into my life (HP 117A). It was a
> PITA. On the east coast (Boston) the signal was erratic
Chris,
My design isn't really that sophisticated hardware wise. Its an 8051
variant, and the CMMR-60P which can be obtained from Sparkfun.com. I do
wind my own antenna, which is just a quad, made from PVC and a metal
electrical box. The circuit sits in the center. It's done with a 2.5 inch
squa
I used to use WWVB before LORAN came into my life (HP 117A). It was a
PITA. On the east coast (Boston) the signal was erratic and often became
untrackable. About half the time, the receiver lost lock at least once per
24 hours, making WWVB an unreliable standard. You really need continuous
trackin
Lenny,
You are ahead of me by many months. I'm building a WWVB receiver
also. Actually I expect I will need to build several before I get
24x7 coverage. My breadboard works only at night in the So.
California area. My plan is to place the entire receiver, antenna
and all on a mast far from th
Greetings All,
This is my first post to this board.
I've completed the first run of a WWVB receiver board and Antenna (custom
wound quad). Its an 8051 microcontroller, with a serial port really, but it
can decode the signal accurately pretty much all day long. (I'm just north
of boston, MA).
I'm
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