Not on the eastern grid, but I had hook my picpet ac mains logger back to the
southwest grid if that would be of any help.
On Nov 15, 2013, at 7:51 PM, Bill Dailey docdai...@gmail.com wrote:
I have my picpet faithfully measuring grid frequency and was wondering if
anyone else if the eastern
On 11/16/2013 08:55 AM, Kevin M. Rosenberg wrote:
Not on the eastern grid, but I had hook my picpet ac mains logger back to the
southwest grid if that would be of any help.
They are separated, so they are not phase coherent. Texas is it's own
grid too.
Cheers,
Magnus
On Nov 15, 2013, at 7:51
Your method tosses out a lot of data. You can't see transients. Ideally
rather then record a 1 second average you'd record the time of EVERY zero
crossing. It sounds like a lot of data but not really. You only record
32 bits 60 times each second. That is 240 bytes per second.
On Fri, Nov
Understood.. I have it every 6 cycles now to sync up with his
synchrophaser. I wrote the script so I can specify the number of cycles I
average. Right now it is at 6 because his measures are every 0.1s.
On Sat, Nov 16, 2013 at 2:52 AM, Chris Albertson
albertson.ch...@gmail.comwrote:
Your
On 11/16/2013 09:52 AM, Chris Albertson wrote:
Your method tosses out a lot of data. You can't see transients. Ideally
rather then record a 1 second average you'd record the time of EVERY zero
crossing. It sounds like a lot of data but not really. You only record
32 bits 60 times each
rough comparison... I didnt have my interval right for this set.
https://www.dropbox.com/s/1gi5tbf96yop5hz/stonercompare.JPG
On Sat, Nov 16, 2013 at 3:02 AM, Bill Dailey docdai...@gmail.com wrote:
Understood.. I have it every 6 cycles now to sync up with his
synchrophaser. I wrote the
Here is a real-time map of mains frequency
http://fnetpublic.utk.edu/gradientmap.html
A common way to measure this is to connect a 9 volt AC plug-in power supply
to the DCD pin of a serial port and let the PPS system log and time stamp
each cycle. You can do it no more hardware than the
would probably be an interesting comparison. I am working with a guy on
the eastern grid part now.
You arent using python for processing on the pc are you? If so, I would be
interested in your script. I am trying to verify I am not a just a little
off with mine.
Bill
On Sat, Nov 16, 2013 at
Hi All,
It seems that NIST changed the location of
http://tf.nist.gov/timefreq/general/pdf. I hope they didn't remove it since
it contained some of my favourite references.
Does anyone know what the new location might be?
Best,
Stephan.
___
time-nuts
Random noise always converts into time jitter. It doesn't
matter how much you amplify the input signal, noise can push
the detected zero crossing wherever it wants to.
-Chuck Harris
Magnus Danielson wrote:
On 11/16/2013 09:52 AM, Chris Albertson wrote:
Your method tosses out a lot of data.
Stephan,
Try again. It looks ok to me. Test with:
http://tf.boulder.nist.gov/general/pdf/1.pdf
You can also use the search page:
http://tf.nist.gov/timefreq/general/publications.htm
/tvb
___
time-nuts mailing list -- time-nuts@febo.com
To
The signal is 120 volts. You hardly need to amplify it. Clip it with a
diode to +- 9 volts so as not to blow up your serial port. But I'd use a
transformer for safety. The zero crossing detectors are built into the
RS232 interface.You take advantage of the RS232 spec which has a DCD
pin
My purpose is to do it with a picpet. That's it. So, that eliminates a bunch
of the options. I can decouple the measurements from the pc clock that way.
Doc
Sent from mobile
On Nov 16, 2013, at 11:26 AM, Chris Albertson albertson.ch...@gmail.com
wrote:
The signal is 120 volts. You
On 11/16/2013 03:13 PM, Chuck Harris wrote:
Random noise always converts into time jitter. It doesn't
matter how much you amplify the input signal, noise can push
the detected zero crossing wherever it wants to.
You are missing that you can alter how much trigger jitter you get.
Cheers,
Doc,
I measure mains time frequency with a picPET all the time. In fact that's one
of the reasons I designed it. If you're having any trouble contact me by email.
/tvb (i5s)
On Nov 16, 2013, at 11:23 AM, Bill Dailey docdai...@gmail.com wrote:
My purpose is to do it with a picpet. That's
No trouble. Easy. I love it. Keeping track of the rolling counters was a
hack because I am so far removed from serious programming.
Sent from mobile
On Nov 16, 2013, at 1:53 PM, Tom Van Baak (lab) t...@leapsecond.com wrote:
Doc,
I measure mains time frequency with a picPET all the
No, I meant the purpose of the whole thing. Why are you measuring power
frequency? Not why are you using a PIC.How will the data be used, what
is the question driving the measurement?
On Sat, Nov 16, 2013 at 11:23 AM, Bill Dailey docdai...@gmail.com wrote:
My purpose is to do it with a
On Sat, Nov 16, 2013 at 09:26:10AM -0800, Chris Albertson wrote:
The signal is 120 volts. You hardly need to amplify it.
I tried this a slightly different way. Since there is mains noise
everywhere, I made a small loop and connected it to a 3.5mm jack
and then plugged that into the mic socket
There is no higher purpose actually. I just fiddle. This is how I relax.
On Sat, Nov 16, 2013 at 3:47 PM, Chris Albertson
albertson.ch...@gmail.comwrote:
No, I meant the purpose of the whole thing. Why are you measuring power
frequency? Not why are you using a PIC.How will the data be
Well indeed interesting updates to the ppt. Most of it is the same as the
earlier decks I have seen so far. Though what I did find interesting is
they now mention navigation and not just PNT. I will guess with the 4 site
senario they are back in the navigation business. There is also a small
note
HI
You can get some pretty crazy propagation at 100 KHz. I suspect they will have
to keep the basic modulation close enough to a proper Loran signal or it will
create major headaches internationally.
I have not dug out the ppt. Do they list station locations yet?
Bob
On Nov 16, 2013, at
Only if the noise in question comes from the trigger electronics.
In the case of a 60Hz mains derived signal, most of the noise is
going to be riding on the signal, and will be amplified with your
gain stage. A -delta amplitude noise signal will be zero when the
sine wave signal is at +delta.
Chuck wrote:
In the case of a 60Hz mains derived signal, most of the noise is
going to be riding on the signal, and will be amplified with your
gain stage.
The potential evils of bandpass filters in a timing chain are well
known, but as long as you can accept the delay of a filter (or
Wildwood is still up at 0100 z 11/17. Guess they are running all weekend.
73,
Bill, WA2DVU
Cape May, NJ
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the
On Sat, Nov 16, 2013 at 7:04 PM, Bill Riches bill.ric...@verizon.netwrote:
Wildwood is still up at 0100 z 11/17. Guess they are running all weekend.
Looks like it is off the air again.
--
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
br...@lloyd.com
+1.916.877.5067
Charles, et al.
I think we agree. Just to clarify...
I rely on no hardware and no software filters when I use a time-stamping
counter such as a sub-nanosecond Pendulum CNT-9x or sub-microsecond picPET. An
electrical zero-crossing happens when it happens. If you filter you're just
trying to
lfphoenix is still on the air. It has not gone down as of 0212 utc.
Regards
Paul
WB8TSL/ Boston
On Sat, Nov 16, 2013 at 8:23 PM, Brian Lloyd br...@lloyd.com wrote:
On Sat, Nov 16, 2013 at 7:04 PM, Bill Riches bill.ric...@verizon.net
wrote:
Wildwood is still up at 0100 z 11/17. Guess they
Tom,
On 11/17/2013 03:02 AM, Tom Van Baak wrote:
Charles, et al.
I think we agree. Just to clarify...
I rely on no hardware and no software filters when I use a time-stamping
counter such as a sub-nanosecond Pendulum CNT-9x or sub-microsecond picPET.
An electrical zero-crossing happens
Again, why are you measuring the AC line? I'd think maybe to measure the
noise that is on it. The fundamental freq. changes second by second.
It's not a clean 60Hz my any means. The rate of frequency change is one
thing you'd like to measure
I was just watching a minute ago and can see a
On 11/17/2013 03:33 AM, Chris Albertson wrote:
Again, why are you measuring the AC line? I'd think maybe to measure the
noise that is on it. The fundamental freq. changes second by second.
It's not a clean 60Hz my any means. The rate of frequency change is one
thing you'd like to measure
When you measure the mains signal, nominally 60 Hz in this case, spikes
etc. is noise which is local and not of interest when comparing over a
large area. Inter-area oscillations have much slower properties.
If you go the time-stamping way, you *should* remove such noise.
Removing or
Again, why are you measuring the AC line? I'd think maybe to measure the
noise that is on it. The fundamental freq. changes second by second.
It's not a clean 60Hz my any means. The rate of frequency change is one
thing you'd like to measure
I was just watching a minute ago and can see a
For a non Time-Nuts application, I needed a narrow bandpass filter that would
provide essentially zero phase shift (no more than 10 or 20uS was desired) over
a frequency range of 55 to 65 Hz while providing useful reduction of the
harmonics, particularly in the range of 400 to 1kHz. This was to
Does an ac transformer hurt me? I was looking for that dang megohm page when I
started this. Couldn't find it so I used a transformer.
Doc
Sent from my iPad
On Nov 16, 2013, at 9:17 PM, Tom Van Baak t...@leapsecond.com wrote:
Again, why are you measuring the AC line? I'd think maybe to
Turns out that professional gear for this does not do time-stamping in
this regard. Rather, they I-Q demodulate the signal with a reference
signal at the nominal rate, low-pass filter it and pay attention to
details of filtering like group-delay and compensation thereof.
It makes sense to me.
tvb wrote:
I think we agree. Just to clarify...
I rely on no hardware and no software filters when I use a
time-stamping counter such as a sub-nanosecond Pendulum CNT-9x or
sub-microsecond picPET. An electrical zero-crossing happens when it
happens. If you filter you're just trying to
This resonates with me somewhat since I used to run nuclear power plants and
operate the actual turbines. It does seem that the time interval measurements
have much more jitter than I would expect. I suspect the thousands of turbines
phase locked may introduce all kinds of very subtle
Tom -
I just had to comment---
Both assume some reasonable limit of mains df/f/dt. You can either
do it with a fancy $100 to $1000 reference signal generator + PLL or FLL + IQ
detector + professional box -- or with a $1 PIC and $0 s/w.
/tvb
You are of course correct. However I would
38 matches
Mail list logo
