Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-13 Thread David G. McGaw
I expect 1/R^2 would prevent such a scheme from working as the terrestrial transmitters would vary widely in signal strength in a way that GPS satellites do not and could overload the receiver. David N1HAC On 3/12/18 9:54 AM, Peter Reilley wrote: Reading this paper makes one wonder if there

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger --> GPS Issues

2018-03-13 Thread Bob kb8tq
Hi > On Mar 12, 2018, at 9:54 AM, Peter Reilley wrote: > > Reading this paper makes one wonder if there are other improvements that > can be made to increase the robustness against jamming, software bugs, solar > events > or hostile attacks to the GPS system > > A

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-13 Thread Peter Reilley
Reading this paper makes one wonder if there are other improvements that can be made to increase the robustness against jamming, software bugs, solar events or hostile attacks to the GPS system A suggestion: Create a parallel terrestrial GPS system.   This would be a system of GPS

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger (

2018-03-12 Thread Dave ZL3FJ
to have it restored. It is apparently quite rare. DaveB, NZ -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Thomas D. Erb Sent: Tuesday, March 13, 2018 00:44 To: time-nuts@febo.com Subject: Re: [time-nuts] Recommendations for Mains Power Monitor

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger (

2018-03-12 Thread Thomas D. Erb
Year ago we used to sell a quartz clock and a 60hz clock mounted on a panel for generator stations on small islands in the Caribbean. This is the way it was done in the 1930's http://electricclock.omeka.net/items/show/6

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-12 Thread d . schuecker
23:13:26: > Von: Attila Kinali <att...@kinali.ch> > An: Discussion of precise time and frequency measurement <time-nuts@febo.com> > Datum: 11.03.2018 23:30 > Betreff: Re: [time-nuts] Recommendations for Mains Power Monitor / Logger > Gesendet von: "time-nuts" <t

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Magnus Danielson
Hi, On 03/11/2018 11:25 PM, Tom Van Baak wrote: >> In short, the GPS to UTC time correction polynomial got screwed up. > > Yes, that was an exciting time! > As far as monitoring mains phase -- a 13 microsecond step would be lost in > the normal jitter and drift of power line timing. My 60 Hz

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Bob kb8tq
Hi If you pick the “right” STM board, it can handle processing up around a megasample. It’s internal ADC’s are more of an issue than the sample rate. You can only do just so well on harmonics with a 12-ish bit ADC. Even if you go crazy and get one with a display, they still are pretty cheap.

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Tom Van Baak
> In short, the GPS to UTC time correction polynomial got screwed up. Yes, that was an exciting time! For newcomers to the list, the bizarre GPS 13 microsecond jump was a hot topic on time-nuts back in 26-Jan-2016. The thread starts with an observation by Paul Boven:

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Attila Kinali
On Sun, 11 Mar 2018 14:41:23 -0500 Dana Whitlow wrote: > I'll have to take a look around to see if there isn't something cheap that > can run > standalone so I don't have to tie up (or wear out) a whole PC for the > acquistion > process. Blub... I should the whole

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Bob kb8tq
Hi Cute !! It certainly beats firing up an R-392 to see if you can get a tick from WWV… Bob > On Mar 11, 2018, at 5:42 PM, Tom Van Baak wrote: > >> “Back in the day” we used WWV and the kitchen clock for that sort of thing…… > > Bob, > > Yes, not much has changed. I

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Attila Kinali
On Sun, 11 Mar 2018 14:41:23 -0500 Dana Whitlow wrote: > Now I'm getting interested in this. My concept is to take the 60 Hz in, do > reasonable > HW filtering to knock off the HF junk that commonly rides on the sinewave, > then use > an RC quadrature phase splitter to

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Tom Van Baak
> “Back in the day” we used WWV and the kitchen clock for that sort of thing…… Bob, Yes, not much has changed. I use multiple methods to measure 60 Hz in order to gain confidence in the results. Besides the picPET, I've used a commercial TrueTime TFDM (Time/Frequency Deviation Meter) and also

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Magnus Danielson
Hi Andy, On 03/11/2018 08:40 PM, Andy Backus wrote: > Thank you for your posting, Magnus. > > Your information is very interesting. > > Do you mind saying a little more about the "incident" on 26-JAN-2016? I > don't find reference to it in the link. And my own TE plot for then shows no >

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Andy Backus
ime-nuts-boun...@febo.com> on behalf of Bill Hawkins <bill.i...@pobox.com> Sent: Saturday, March 10, 2018 11:40 PM To: 'Bob Albert'; 'Discussion of precise time and frequency measurement'; 'Patrick Murphy' Subject: Re: [time-nuts] Recommendations for Mains Power Monitor /

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Dana Whitlow
Now I'm getting interested in this. My concept is to take the 60 Hz in, do reasonable HW filtering to knock off the HF junk that commonly rides on the sinewave, then use an RC quadrature phase splitter to yield I & Q signals. Then sample at 1PPS with my Rb's PPS as the sample trigger, and

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Attila Kinali
Hi, I'd like to add two things: On Sat, 10 Mar 2018 20:46:16 -0800 "Tom Van Baak" wrote: > 1) Safety. I usually use a low voltage step-down transformer. This gives > isolation and safety. Anything from 3 VAC to 24 VAC is fine. Please, do not just add a transformer. Make

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Ryan Stoner
I used to have one of the FNET units to help them with data and to keep track of things myself during a period of low voltage in the summer months. The lowest voltage I saw was about 70 volts. Months of contacting ComEd directly with the excellent data provided by the unit accomplished nothing. An

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Magnus Danielson
Hi, On 03/11/2018 12:53 PM, Bob kb8tq wrote: > Hi > > So, how good is “good enough?”. My first attempt ran a counter with a 1 us > period resolution. > (remember, it was tube based …). That turned out to be major overkill in > terms of line frequency > measurement. 60.123 Hz is doing pretty

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Didier Juges
I like the sound card idea. However I believe it's much better to use the two channels. At least under Windows, it is much easier to track the relative phase of the two channels of one sound card than the absolute phase of one channel compared to the system clock. I have written an audio VNA in

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread ewkehren via time-nuts
> Subject: Re: [time-nuts] Recommendations for Mains Power Monitor / Logger Bob, Correct, measuring mains frequency to a couple of digits is not hard. What makes an interesting challenge is to monitor mains, "kitchen clock", phase drift. And to do it with cycle accuracy; no slips

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Bob kb8tq
ST a few hours ago. > > - Original Message - > From: "Bob kb8tq" <kb...@n1k.org> > To: "Discussion of precise time and frequency measurement" > <time-nuts@febo.com> > Sent: Sunday, March 11, 2018 4:53 AM > Subject: Re: [time-nuts] Recomme

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Bob kb8tq
Hi So, how good is “good enough?”. My first attempt ran a counter with a 1 us period resolution. (remember, it was tube based …). That turned out to be major overkill in terms of line frequency measurement. 60.123 Hz is doing pretty well in terms of line frequency. Even to get that level, you

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-11 Thread Bill Hawkins
Well, this synchronization follows the laws of physics. If the energy generated doesn't equal the energy consumed, then the frequency may raise or lower. This is for steam turbines. If the energy come front an inverter from a DC tie line, as it does from the four regions in the US, the frequency

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-10 Thread Tom Van Baak
> I've done some Googling and have found any number of designs. Pat, 1) Safety. I usually use a low voltage step-down transformer. This gives isolation and safety. Anything from 3 VAC to 24 VAC is fine. 2) Trigger. There are dozens of schematics on the web for capturing the zero-crossing of a

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-10 Thread Bob Albert via time-nuts
There isn't a whole lot of justification for measuring power line frequency.  We are all synchronized (in the first world at least) and while there are phase instabilities, it's seldom the frequency varies enough to overcome the noise. As for voltage, it's much more steady than several years

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-10 Thread Jeremy Nichols
One possibility is to get an FNET/GridEye unit of the University of Tennessee's monitoring stations. Operated by the Power Information Technology Laboratory at the University of Tennessee , FNET/GridEye is a low-cost, quickly deployable

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-10 Thread Bob kb8tq
Hi The most basic question is - what do you have already? My first adventure with line monitoring was with a vacuum tube based counter. It was what I just happened to have. One basic need is something to monitor against. GPS is a pretty cheap option if you have nothing already. Rather

Re: [time-nuts] Recommendations for Mains Power Monitor / Logger

2018-03-10 Thread Hal Murray
I know of two ways to monitor frequency. One is to use one of tvb's PICs. That needs a good frequency reference, probably a GPSDO. The other is to use the PPS input on a Linux box. That uses the system clock so you meed a good NTP setup. Some of the APS family of UPS boxes will monitor the