Re: [time-nuts] White LED's
Max Robinson wrote: I remember hearing about a law suit in an engineering law class I had to take way back when. It seems a farmer had a long fence running under and parallel to a high tension distribution line. He had hidden a copper line in it and was harvesting enough power to operate most of his farm buildings. This amounted to a measurable loss from the distribution line and the power company found him out and sued. The court ruled he had to pay for power used in the past and stop getting his power that way. Considering the source I don't think this is an urban legend. Regards. Max. K 4 O D S. It sounds a bit of a myth to me. I've never done the maths, but I doubt you could get a lot of power from a wire like this. To power most of his farm machinery would need many kW. On the very high power lines, they tend to be location very high, in which case I would have thought the fields should cancel at long distances, as there will be 3 out of phase currents. I think for lighting, you might be able to claim you did it to reduce the E-field at your house, as you were worried by the health effects. Sine you need to dump the power somewhere, a light bulb seemed the cheapest dummy load. A 100 W light bulb is a lot cheaper than a 100 W resistor! On a similar note, I heard about someone who powered his greenhouse by using the small voltage between neutral and earth that will exist. I know there is at least 30 mA available at my house, as shorting neutral to earth will trip a 30 mA RCD. But I measured the voltage once, and whilst I can't recall what it was, it was less than 1 Volt. Dave ___ 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 instructions there.
Re: [time-nuts] [OT] Ikea Lamp
Not wishing to push this O/T thread more O/T but coming from England, and now in New Zealand, we have these sodium streetlights which I think are a pain in the neck. They have only two narrow spectra of yellow light and although they produce light it makes it hard, if not impossible, to make out colours. I wonder if they are being used in other members countries? Steve 2010/1/31 Dave Martindale dave.martind...@gmail.com: If you care about accurate colour rendering, stick with incandescent, preferably halogen. White LEDs are actually blue LEDs coated with a phosphor that absorbs some of the blue light and emits approximately yellow instead. If you look at the spectrum, you'll see a broad yellow peak and a narrower blue peak. Your eyes see it as approximately white, but it's deficient in red and green compared to a black body emitter like hot tungsten. On the other hand, it's not as spiky as the output of fluorescents. -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ 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 instructions there.
Re: [time-nuts] [OT] Ikea Lamp
Hi Steve,They do use them in the USA.The advantages are,1 High efficiency2 Better visibility in rain and fog. As there is only one main colour you do not get diffraction rainbows.3 Kind to astronomers. A simple narrow stop band optical filter allows astronomers to remove the light pollution. In some areas around observatories they are mandated by local planning regulations. These are considered to outweigh the disadvantage of no colour rendition. Robert G8RPI. --- On Sun, 31/1/10, Steve Rooke sar10...@gmail.com wrote: From: Steve Rooke sar10...@gmail.com Subject: Re: [time-nuts] [OT] Ikea Lamp To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Sunday, 31 January, 2010, 9:19 Not wishing to push this O/T thread more O/T but coming from England, and now in New Zealand, we have these sodium streetlights which I think are a pain in the neck. They have only two narrow spectra of yellow light and although they produce light it makes it hard, if not impossible, to make out colours. I wonder if they are being used in other members countries? Steve 2010/1/31 Dave Martindale dave.martind...@gmail.com: If you care about accurate colour rendering, stick with incandescent, preferably halogen. White LEDs are actually blue LEDs coated with a phosphor that absorbs some of the blue light and emits approximately yellow instead. If you look at the spectrum, you'll see a broad yellow peak and a narrower blue peak. Your eyes see it as approximately white, but it's deficient in red and green compared to a black body emitter like hot tungsten. On the other hand, it's not as spiky as the output of fluorescents. -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ 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 instructions there. ___ 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 instructions there.
Re: [time-nuts] Conducting Bench Top Material
Mark Sims wrote: Sulphur flower is ground sulphur raw sulphur. Flowers of sulphur is precipitated out of sulphuric acid. The distinction is subtle, but can be quite deadly if you do pyrotechnics. Flowers of sulphur can be highly acidic and reacts violently with chlorate compounds. Hmm... what colour would mercury give to the pyrotechnics? Cheers, Magnus ___ 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 instructions there.
Re: [time-nuts] Conducting Bench Top Material
In France, it is known as fleur de souffre, which translates litterally to flower of sulphur. In French, there is no confusion possible between the terms flower (fleur) and flour (farine). Didier -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Saturday, January 30, 2010 10:05 PM To: Bruce Griffiths Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Conducting Bench Top Material Among chemists, it's flour of sulpher. Flowers is an (incorrect archeic) popular name, like quicksilver. -John === It is known (for whatever reason) as flowers of sulphur by gardeners medical practitioners (althernative and conventional) and others outside the US. http://www.websters-online-dictionary.org/fl/flower+of+sulphur.html http://mysite.du.edu/~jcalvert/phys/sulphur.htm http://mysite.du.edu/%7Ejcalvert/phys/sulphur.htm It is a powder produced by sublimation of sulphur. Bruce ___ 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 instructions there.
[time-nuts] Administrivia: On Topic Posts, Please!
All -- While I have enjoyed the recent threads about benchtops, CFLs, LEDs, etc., they really aren't on topic for this list, and we all need to exercise some restraint. While I think the incredible knowledge and inquisitiveness of this group lead naturally to digressions, and those digressions can be both fascinating and informative, we need to remember that the list's charter is to be a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. We're now at over 900 subscribers, so please consider the charter and the audience, and show consideration for the hundreds of people who may not be interested when threads get so far off topic. Thanks, John ___ 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 instructions there.
Re: [time-nuts] time-nuts Digest, Vol 66, Issue 171
Morris, Hg is a liquid at room temperature. It evaporates into gaseous Hg. It disappears from all these little reservoirs. So there is no chance of long term Hg build up on floors in medical facilities. Here's an experiment we did as children. Apply a small amount of Hg to a silver coin. The coin becomes very silvery and very slick with little friction. This is only temporary though. The Hg evaporates over night and the coin is back to it's dull color the next day. As a disclaimer, I don't advise doing this experiment today. Stork -- Message: 3 Date: Sun, 31 Jan 2010 13:56:20 +1100 From: Morris Odell Subject: Re: [time-nuts] Conducting Bench Top Material To: Message-ID: 01caa220$f73836b0$e5a8a4...@net.au Content-Type: text/plain;charset=us-ascii Just about every doctor's surgery or emergency room more than about 15 years old will have had more than one thermometer broken in it. I'm sure there are lots of little balls of mercury lurking in carpet fibres or between tiles in those environments. It doesn't seem to have surfaced as an occupation health hazard. You're more likely to encounter lead or sharp steel poisoning in inner city ERs :-( Morris Date: Sat, 30 Jan 2010 17:22:30 -0500 From: Chuck Harris Subject: Re: [time-nuts] Conducting Bench Top Material Yes, and no. When mercury hits the ground, it splatters into hundreds of miniballs of mercury. When you walk on them, they further fracture, and by the time you are done, you have increased the surface area of the mini drop of mercury greatly... probably thousands of times. That increases the mercury vapor emitted into the room. Is it harmful? Maybe. Maybe not. *** ___ 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 instructions there.
Re: [time-nuts] Conducting Bench Top Material
In my 1963 EH Sargent and Company catalog, they list: Sulfur, USP, Precipitated Powder Sulfur, NF Sublimed Powder Sulfur, Sublimed Flowers (Tech) Sulfur, Lump (Roll) And something about Seconds, NIST Grade... -Chuck Harris Don Latham wrote: The connection is alchemical, Don - Original Message - From: Bruce Griffiths bruce.griffi...@xtra.co.nz To: j...@quik.com; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, January 30, 2010 8:53 PM Subject: Re: [time-nuts] Conducting Bench Top Material It is known (for whatever reason) as flowers of sulphur by gardeners medical practitioners (althernative and conventional) and others outside the US. http://www.websters-online-dictionary.org/fl/flower+of+sulphur.html ___ 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 instructions there.
Re: [time-nuts] [OT] Ikea Lamp
Steve Rooke wrote: Not wishing to push this O/T thread more O/T but coming from England, and now in New Zealand, we have these sodium streetlights which I think are a pain in the neck. They have only two narrow spectra of yellow light and although they produce light it makes it hard, if not impossible, to make out colours. I wonder if they are being used in other members countries? Sweden has them. It's the classical sodium D1 and D2 lines. Kind of neat that one can calibrate ones spectrometer by the highway. :) I think white is becoming more popular now. Cheers, Magnus ___ 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 instructions there.
[time-nuts] Austron 1150
Has any one done testing on the Austron 1150 oscillator module, specifically Allan Variance. Thank you Bert KehrenMiami ___ 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 instructions there.
Re: [time-nuts] White LED's
I believe that it is possible to light a fluorescent tube, at least dimly, by standing on the ground under a power transmission line operating at more than 100 kV , holding one end of the tube in your hand, and sticking the other end up in the air. I have never done _this_, exactly, but I have held a fluorescent tube near a ham antenna and seen it light, and on the web I have seen photos of people doing it under electric utility lines. Of course I have seen fluorescent tubes light near Van de Graaff generators and Tesla coils. We all have. However, such machines generate E-fields much stronger than you'll find near ground level under an electric utility line. I do _not_ believe that one could get a fluorescent tube to light by holding it near ground level under an 11-kV line. But this is just my gut feeling. I could certainly be wrong. I have not done the experiment; nor have I done a calculation of the expected field strength. The story of a farmer drawing enough power to operate most of his farm buildings from a wire running under and parallel to a HV line sounds like an urban legend to me. As does the story of a guy that had a big coil of wire in the roof of his shed and... could light a 100W incandescent bulb from the stray fields. It's _hard_ to draw significant power from the field surrounding a power line because a huge reactance must be tuned out. If it were easy, then power- transmission companies would be dissipating substantial and economically intolerable amounts of power in the _ground_, which has non-negligible conductivity. During my summer working in the engineering department of a Bell System operating company, I personally observed examples of 60-Hz AC e.m.f. induced longitudinally in telephone cables running for miles along rural pole lines, directly under 60-Hz power lines. It was not unusual to see an induced e.m.f. of the order of 100 V RMS. A person could get a painful shock from this voltage. However, a human is a pretty high-resistance load. You could _not_ draw watts of power from such a source. The Thevenin equivalent source impedance was too high. BTW, it is necessary to distinguish induced e.m.f. from a potential difference between separated points on the surface of the ground due to _resistance_ in the ground multiplied by _conduction_ current in the ground. Conduction current in the ground arises whenever less than 100% of the current flowing in a single-phase power line, or the common-mode current in a three-phase line, does not return through the neutral wire/cable of the line. In rural areas where most of the loads are single-phase, and a three-phase line is tapped for single- phase loads separated by miles or more, it is not unusual to find very high ground currents. I remember observing symptoms of high ground currents also near electric railroad lines. As electric locomotive such as the Pennsylvania RR's GG-1 drew single-phase 25-Hz current from an overhead wire and returned it through the rails; but a significant fraction of the return current flowed through the ground, because the rails were connected to driven ground rods, presumably for safety. Trolley cars on the streets of Baltimore ran on DC, and did the same thing. Some of the ground current would find its way via safety-ground rods through the neutral wires of the 60-Hz electric utility. When this DC flowed through the windings of 60-Hz power transformers, it partially saturated the transformer cores, causing waveform distortion, so that 60-Hz harmonics were heard in neighborhood telephones. The notion of ground as one big equipotential surface, an infinite sink for charge / current, is a mass delusion. It's a delusion for DC and low-frequency AC. For RF, it is so wrong that words fail me. -John === I remember hearing about a law suit in an engineering law class I had to take way back when. It seems a farmer had a long fence running under and parallel to a high tension distribution line. He had hidden a copper line in it and was harvesting enough power to operate most of his farm buildings. This amounted to a measurable loss from the distribution line and the power company found him out and sued. The court ruled he had to pay for power used in the past and stop getting his power that way. Considering the source I don't think this is an urban legend. Regards. Max. K 4 O D S. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com - Original Message - From: Chuck Harris cfhar...@erols.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, January 30, 2010 12:21
Re: [time-nuts] Austron 1150
Hi I haven't tested one in about 20 years. I don't remember exact numbers. It's a good low phase noise oscillator ( similar to the 10811). It's not optimized for short term stability past about 10 seconds. They had other products in the line up that did better in that respect. Bob -- From: ewkeh...@aol.com Sent: Sunday, January 31, 2010 10:53 AM To: time-nuts@febo.com Subject: [time-nuts] Austron 1150 Has any one done testing on the Austron 1150 oscillator module, specifically Allan Variance. Thank you Bert KehrenMiami ___ 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 instructions there. ___ 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 instructions there.
Re: [time-nuts] [OT] Ikea Lamp
There are actually two kinds of Na lights, high and low pressure. The low pressure ones are mostly a line spectrum and look darkish orange. In the high pressure ones, the Na lines are strongly pressure broadened and give a lighter orange color. http://en.wikipedia.org/wiki/Sodium-vapor_lamp In a similar vein, Prof. Norman Ramsey at Harvard built a GIANT atomic clock experiment in an aluminum tank maybe 6' in diameter and 8' long. By the 1980s it had ceased to be used for experiments and was a giant equipment cupboard in the lab. The tank was enclosed in a giant plywood box with insulation. It eventually took a guy a couple of days with a Sawzall to cut it in half to get it out of the basement when he retired! http://en.wikipedia.org/wiki/Norman_Foster_Ramsey,_Jr. -John == Hi Steve,They do use them in the USA.The advantages are,1 High efficiency2 Better visibility in rain and fog. As there is only one main colour you do not get diffraction rainbows.3 Kind to astronomers. A simple narrow stop band optical filter allows astronomers to remove the light pollution. In some areas around observatories they are mandated by local planning regulations. These are considered to outweigh the disadvantage of no colour rendition. Robert G8RPI. --- On Sun, 31/1/10, Steve Rooke sar10...@gmail.com wrote: From: Steve Rooke sar10...@gmail.com Subject: Re: [time-nuts] [OT] Ikea Lamp To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Sunday, 31 January, 2010, 9:19 Not wishing to push this O/T thread more O/T but coming from England, and now in New Zealand, we have these sodium streetlights which I think are a pain in the neck. They have only two narrow spectra of yellow light and although they produce light it makes it hard, if not impossible, to make out colours. I wonder if they are being used in other members countries? Steve 2010/1/31 Dave Martindale dave.martind...@gmail.com: If you care about accurate colour rendering, stick with incandescent, preferably halogen. White LEDs are actually blue LEDs coated with a phosphor that absorbs some of the blue light and emits approximately yellow instead. If you look at the spectrum, you'll see a broad yellow peak and a narrower blue peak. Your eyes see it as approximately white, but it's deficient in red and green compared to a black body emitter like hot tungsten. On the other hand, it's not as spiky as the output of fluorescents. -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ 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 instructions there. ___ 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 instructions there. ___ 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 instructions there.
[time-nuts] Help from NTS-200 experts
I bought an NTS-200 a few months ago. Although sold as used, it was clearly a NOS – software on version 1.0, protection plastic over the LCD. After a power outage, the LCD illumination disappeared – all other functions remained OK. I checked the LCD contacts and they seem to be ok. Is there any command to lit/unlit the LCD? Is there a smuggled schematics somewhere? r Any other suggestion? -- Geraldo Lino de Campos gera...@decampos.net ___ 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 instructions there.
Re: [time-nuts] Help from NTS-200 experts
How about the LCD backlight? It may have died. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Geraldo Lino de Campos Sent: Sunday, January 31, 2010 1:14 PM To: time-nuts@febo.com Subject: [time-nuts] Help from NTS-200 experts I bought an NTS-200 a few months ago. Although sold as used, it was clearly a NOS - software on version 1.0, protection plastic over the LCD. After a power outage, the LCD illumination disappeared - all other functions remained OK. I checked the LCD contacts and they seem to be ok. Is there any command to lit/unlit the LCD? Is there a smuggled schematics somewhere? r Any other suggestion? -- Geraldo Lino de Campos gera...@decampos.net ___ 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 instructions there. ___ 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 instructions there.
[time-nuts] FTS 5030 Comments ?
I saw an FTS 5030 Cesium Standard and thought it might be useful. But, before I sink major coin into this, I thought I would get the opinions of the group. Thanks, Dick, W1KSZ There is currently an FTS 6006 controller on Ebay for the FTS 5030 modular Cs unit. Is the modular FTS 5030 unit radically different than the 5030 assembly in the FTS 4060 standard? ___ 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 instructions there.
Re: [time-nuts] Self winding clock co. Weatern union clock
Hi Corby: The clocks were on a synchronization line in series and the source power supply was 200 VDC. A high power adjustable series resistor was in series to set the loop current. The loop was closed one second prior to top of the hour and opened at the top of the hour. The reason for the high voltage is that the time constant is L/R so the higher the R the faster is the circuit. This is exactly the same as how Teletype machines are able to operate. You can use a bench power supply in constant current mode and just turn up the current until the synchronizer pulls in and not the voltage across it. See: http://www.prc68.com/I/SWCC.shtml http://www.prc68.com/I/SWCC2.shtml Have Fun, Brooke Clarke http://www.PRC68.com Corby Dawson wrote: Hi, I picked up a nice big clock that has self winding clock co. New York and western union on the face. After some research on the web I connected a 3V battery up and it wound itself OK. Fiddled with the orientation a bit to get the pendulum swing balanced and it seems to be running OK now. How to I advance or retard the hands to set the time? Also how do I test the synchronizer? I see two Fahnestock clips That look to connect to the synchronizer solenoid. With an appropriate interface can I synchronize it to a GPS 1PPH? Thanks, Corby Dawson Small Business Tools Compete with the big boys. Click here to find products to benefit your business. http://thirdpartyoffers.juno.com/TGL2141/c?cp=rp_3jEZUzZpJUtop_lLe_QAAJ1ABLZFyqoH-WnHH1GJ345whAAYAAADNAAARMQA= ___ 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 instructions there. ___ 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 instructions there.
Re: [time-nuts] Self winding clock co. Weatern union clock
Brooke, It's humbling to know that someone on the Internet already has found the answer to something that puzzles me. Worse, I had a feeling of déjà vu as I read your article. You asked about the Type A pendulum in the article. I looked to see if Google had found an answer. It had. The link is: http://www.kensingtonclock.com/kcsadjust.htm Look down near the bottom of the article where a figure shows the three types - A, B, and C. There's a few paragraphs about the striking mechanism, and then all is revealed. Thanks for maintaining a very informative site. Bill Hawkins O.T.P.S. If anyone is trying to play tapes made between 1975 and 1985, and they stick so bad they won't play, look up baking tapes before you destroy them. The sticking can be fixed. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: Sunday, January 31, 2010 4:03 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Self winding clock co. Weatern union clock Hi Corby: The clocks were on a synchronization line in series and the source power supply was 200 VDC. A high power adjustable series resistor was in series to set the loop current. The loop was closed one second prior to top of the hour and opened at the top of the hour. The reason for the high voltage is that the time constant is L/R so the higher the R the faster is the circuit. This is exactly the same as how Teletype machines are able to operate. You can use a bench power supply in constant current mode and just turn up the current until the synchronizer pulls in and not the voltage across it. See: http://www.prc68.com/I/SWCC.shtml http://www.prc68.com/I/SWCC2.shtml Have Fun, Brooke Clarke http://www.PRC68.com Corby Dawson wrote: Hi, I picked up a nice big clock that has self winding clock co. New York and western union on the face. After some research on the web I connected a 3V battery up and it wound itself OK. Fiddled with the orientation a bit to get the pendulum swing balanced and it seems to be running OK now. How to I advance or retard the hands to set the time? Also how do I test the synchronizer? I see two Fahnestock clips That look to connect to the synchronizer solenoid. With an appropriate interface can I synchronize it to a GPS 1PPH? Thanks, Corby Dawson Small Business Tools Compete with the big boys. Click here to find products to benefit your business. http://thirdpartyoffers.juno.com/TGL2141/c?cp=rp_3jEZUzZpJUtop_lLe_QAAJ1ABLZ FyqoH-WnHH1GJ345whAAYAAADNAAARMQA= ___ 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 instructions there. ___ 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 instructions there. ___ 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 instructions there.
[time-nuts] Data on a Vectron CO233FW-R ?
Does anyone have any data on the above Oscillator Module? Likely Phase Noise? 100 MHz. I suspect not ovened but it has an SMA output and looks as though it ought to be of good quality. I am contemplating using it to multiply up to 400 or 500 MHz for a DDS reference in my transceiver project. Thanks Dan ac6ao / g3ncr ___ 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 instructions there.
Re: [time-nuts] Data on a Vectron CO233FW-R ?
Dan Rae wrote: Does anyone have any data on the above Oscillator Module? Likely Phase Noise? 100 MHz. I suspect not ovened but it has an SMA output and looks as though it ought to be of good quality. I am contemplating using it to multiply up to 400 or 500 MHz for a DDS reference in my transceiver project. Thanks Dan ac6ao / g3ncr http://www.vectron.com/products/xo/co-233f_233fw.htm R option is +13dBm output. Phase noise floor for the standard version isn't stellar (~ -145dBc/Hz) Bruce ___ 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 instructions there.
Re: [time-nuts] [OT] Ikea Lamp
I hate the yellow lamps in my area because they are only found in certain vicinities. You're driving along at night, maybe searching for something, and suddenly one of the street lamps turns red! It's happened to me a few times... Dave - Original Message - From: Robert Atkinson robert8...@yahoo.co. uk To: Discussion of precise time and frequency measurement time-nuts@ febo .com Sent: Sunday, January 31, 2010 4:34:23 AM GMT -07:00 US/Canada Mountain Subject: Re: [time-nuts] [OT] Ikea Lamp Hi Steve,They do use them in the USA.The advantages are,1 High efficiency2 Better visibility in rain and fog. As there is only one main colour you do not get diffraction rainbows.3 Kind to astronomers. A simple narrow stop band optical filter allows astronomers to remove the light pollution. In some areas around observatories they are mandated by local planning regulations. These are considered to outweigh the disadvantage of no colour rendition. Robert G8RPI. --- On Sun, 31/1/10, Steve Rooke sar10538@ gmail .com wrote: From: Steve Rooke sar10538@ gmail .com Subject: Re: [time-nuts] [OT] Ikea Lamp To: Discussion of precise time and frequency measurement time-nuts@ febo .com Date: Sunday, 31 January, 2010, 9:19 Not wishing to push this O/T thread more O/T but coming from England, and now in New Zealand , we have these sodium streetlights which I think are a pain in the neck. They have only two narrow spectra of yellow light and although they produce light it makes it hard, if not impossible, to make out colours. I wonder if they are being used in other members countries? Steve 2010/1/31 Dave Martindale dave . martindale @ gmail .com: If you care about accurate colour rendering, stick with incandescent, preferably halogen. White LEDs are actually blue LEDs coated with a phosphor that absorbs some of the blue light and emits approximately yellow instead. If you look at the spectrum, you'll see a broad yellow peak and a narrower blue peak. Your eyes see it as approximately white, but it's deficient in red and green compared to a black body emitter like hot tungsten. On the other hand, it's not as spiky as the output of fluorescents . -- Steve Rooke - ZL3TUV G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. ___ 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 instructions there. ___ 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 instructions there. ___ 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 instructions there.
[time-nuts] Zero dead time and average frequency estimation
Fellow time-nuts, I keep poking around various processing algorithms trying to figure out what they do and perform. One aspect which may be interesting to know about is the use of zero dead time phase or frequency data and the frequency estimation from that data. One may be compelled to differentiate the time data into frequency data by using nearby data samples, according to y(i) = (x(i+1)-x(i))/tau0 and then just form the average of those. The interesting thing about that calculations is that the x(i+1) and x(i) terms cancels except for x(1) and x(N) so effectively only two samples of phase data is being used. This is a simple illustration of how algorithms may provide less degrees of freedom than one may initially assume it to have (N-1 in this case). Similar type of cancellation occurs in linear drift estimation. Maybe this could spark some interest in the way one estimates the various parameters and what different estimators may do to cancel noise of individual samples. Cheers, Magnus ___ 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 instructions there.
Re: [time-nuts] Zero dead time and average frequency estimation
Magnus, Correct, all the terms cancel between the end points. Note that this is exactly equivalent to the way a traditional gated frequency counter works -- you open the gate, wait some sample period (maybe 1, 10, or 100 seconds) and then close the gate. In this scenario it's clear that all the phase information during the interval is ignored; the only points that matter are the start and the stop. Modern high-resolution frequency counters don't do this; and instead they use a form of continuous counting and take a massive number of short phase samples and create a more precise average frequency out of that. There are some excellent papers on the subject; start with the one by Rubiola: http://www.femto-st.fr/~rubiola/pdf-articles/journal/2005rsi-hi-res-freq-counters.pdf There are additional papers (perhaps Bruce can locate them). I wonder if fully overlapped frequency calculations would be one solution to your query; similar to the advantage that the overlapping ADEV sometimes has over back-to-back ADEV. Related to that, I recently looked into the side-effects of using running averages on phase or frequency data, specifically what it does to a frequency stability plot (ADEV). See: http://www.leapsecond.com/pages/adev-avg/ Not surprising, you get artificially low ADEV numbers when you average in this way; the reason is that running averages, by design, tend to smooth out (low pass filter) the raw data. One thing you can play with is computing average frequency using the technique that MDEV uses. /tvb - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, January 31, 2010 6:53 PM Subject: [time-nuts] Zero dead time and average frequency estimation Fellow time-nuts, I keep poking around various processing algorithms trying to figure out what they do and perform. One aspect which may be interesting to know about is the use of zero dead time phase or frequency data and the frequency estimation from that data. One may be compelled to differentiate the time data into frequency data by using nearby data samples, according to y(i) = (x(i+1)-x(i))/tau0 and then just form the average of those. The interesting thing about that calculations is that the x(i+1) and x(i) terms cancels except for x(1) and x(N) so effectively only two samples of phase data is being used. This is a simple illustration of how algorithms may provide less degrees of freedom than one may initially assume it to have (N-1 in this case). Similar type of cancellation occurs in linear drift estimation. Maybe this could spark some interest in the way one estimates the various parameters and what different estimators may do to cancel noise of individual samples. Cheers, Magnus ___ 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 instructions there.
Re: [time-nuts] Zero dead time and average frequency estimation
Gentlemen, You've hit a topic I've become more confused about after researching some of the original papers on this subject. Here are a few questions which I would like to become educated about. 1) Will the calculated results of ADEV, ODEV, MDEV TOTDEV suggest which result applies best to the data being analyzed? 2) What attributes of the data to be analyzed suggest which computation is most appropriate? 3) Will some computed results indicate that the analysis is NOT appropriate? (Are false results obvious?) I'm sure there are more aspects worth learning than these, but they might serve to get a conversation underway. Any enlightenment would be greatly appreciated. Pete Rawson On Jan 31, 2010, at 8:50 PM, Tom Van Baak wrote: Magnus, Correct, all the terms cancel between the end points. Note that this is exactly equivalent to the way a traditional gated frequency counter works -- you open the gate, wait some sample period (maybe 1, 10, or 100 seconds) and then close the gate. In this scenario it's clear that all the phase information during the interval is ignored; the only points that matter are the start and the stop. Modern high-resolution frequency counters don't do this; and instead they use a form of continuous counting and take a massive number of short phase samples and create a more precise average frequency out of that. There are some excellent papers on the subject; start with the one by Rubiola: http://www.femto-st.fr/~rubiola/pdf-articles/journal/2005rsi-hi-res-freq-counters.pdf There are additional papers (perhaps Bruce can locate them). I wonder if fully overlapped frequency calculations would be one solution to your query; similar to the advantage that the overlapping ADEV sometimes has over back-to-back ADEV. Related to that, I recently looked into the side-effects of using running averages on phase or frequency data, specifically what it does to a frequency stability plot (ADEV). See: http://www.leapsecond.com/pages/adev-avg/ Not surprising, you get artificially low ADEV numbers when you average in this way; the reason is that running averages, by design, tend to smooth out (low pass filter) the raw data. One thing you can play with is computing average frequency using the technique that MDEV uses. /tvb - Original Message - From: Magnus Danielson mag...@rubidium.dyndns.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, January 31, 2010 6:53 PM Subject: [time-nuts] Zero dead time and average frequency estimation Fellow time-nuts, I keep poking around various processing algorithms trying to figure out what they do and perform. One aspect which may be interesting to know about is the use of zero dead time phase or frequency data and the frequency estimation from that data. One may be compelled to differentiate the time data into frequency data by using nearby data samples, according to y(i) = (x(i+1)-x(i))/tau0 and then just form the average of those. The interesting thing about that calculations is that the x(i+1) and x(i) terms cancels except for x(1) and x(N) so effectively only two samples of phase data is being used. This is a simple illustration of how algorithms may provide less degrees of freedom than one may initially assume it to have (N-1 in this case). Similar type of cancellation occurs in linear drift estimation. Maybe this could spark some interest in the way one estimates the various parameters and what different estimators may do to cancel noise of individual samples. Cheers, Magnus ___ 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 instructions there. ___ 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 instructions there.
[time-nuts] help from Electronic Vibration Compensation
Now I am interested in low-g oscillators. http://www.freqelec.com/oscillators/g-comp_qz_brfg_04-07.pdf Which accelerometer is selected in the low-g oscillator? How to hack my normal oscillator to low-g one ? Anynbsp;othernbsp;suggestion? wei ___ 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 instructions there.
