Re: [time-nuts] Rb cooling
same thoughts almost the same fan mine are 50 mm square and less than 10 mm. Mine are from a dead plasma display. Best regards Bert In a message dated 7/17/2011 10:15:41 P.M. Eastern Daylight Time, charles_steinm...@lavabit.com writes: Bert wrote: Charles sounds like what I am doing. What size fan do you use? It's 40 mm square, and quite thin ( 10 mm), from a dead hard drive. At normal indoor temperatures (20-25C), it spins from 100-200 rpm. I chose 45C for the baseplate temperature so it can be used at any ambient temperature I'm likely to encounter. 40C was, I thought, just a touch too low for that. Best regards, Charles ___ 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] Rb cooling
On 18/07/11 06:40, Chuck Harris wrote: I understand that, but you didn't answer my question: Has anyone seen any failures that are attributable to heat? 50 year theoretical life vs 75 theoretical year life probably isn't going to be too significant. 1 year life vs 10 year would be. These GPSDO's are made to run with their ovens powered, and hot. Surely the manufacturer took a little time to select parts that would survive the intended operating environment. Cooling down an oven is not a good thing, as it simply ups the power the oven control circuitry dumps into the oven to keep it hot. Actually it is two-folded... You do need a certain amount of cooling such that the oven remain in a linear control-state. If you have too little cooling, the oven will turn off completely for periods and then click in and heat up and then turn off again. I've seen what this does to the frequency and it is not nice. You do not want too much cooling, or you will draw a lot of current in the heating regulator and this will shorten the life of that transistor(s) significantly as it is both hot and operating with high current, a double-bad situation. So, instead of just slabbing a big passive radiator there or a strong cooling fan, what I was discussing and what Charles and Bert has been implementing is a temperature controlled cooling. I agree that the temperature needs to be higher than ambient, but with an active cooling you can have higher cooling dynamics than otherwise be premisable, so the baseplate temperature may be higher than for a passive radiator. If you want to use the iron stabilisation proposed by Poul-Henning, which can be an additional trick to use, mounting pre-heating resistors on the iron body to pre-heat it up to operating range may be recommended, since the heaters of the rubidium oven isn't that powerful and the heat capacity of a big iron lump can be quite significant. Essentially, it behaves like an oven, just that the main controlling mechanism lies in cooling rather than heating. Pre-heating of iron blob just fits the picture. 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] Primary Time Standards
Magnus Danielson mag...@rubidium.dyndns.org wrote: If you read the fine-print, the SI second is now defined for sea-level gravity and at 0 K black-body raditation, so compensation for these effects should be done. The definition of the second is independent of your frame of reference, otherwise it wouldn't be a universal unit of measurement. When the SI second is used to create a timescale then it must be referred to a standard frame of reference. In the case of TAI and UTC, the frame of reference is the rotating geoid. Tony. -- f.anthony.n.finch d...@dotat.at http://dotat.at/ South-east Iceland: Northerly or northeasterly 5 to 7, decreasing 4 in west. Moderate or rough. Showers. Moderate or good. ___ 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] The future of UTC
Jose Camara camar...@quantacorp.com wrote: I think before adding to the fire of UTC1, UTC7 etc. why not just abolish this silliness called Daylight Savings Time? If there is any benefit to it, just change business operating hours instead. If you want to know why your suggestion doesn't work, David Prerau has collected many many examples. http://www.seizethedaylight.com/ Tony. -- f.anthony.n.finch d...@dotat.at http://dotat.at/ Fair Isle: Northerly or northeasterly 4 or 5 increasing 5 or 6, but 6 or 7 in far west at first. Moderate or rough. Rain or showers. Moderate or poor. ___ 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] The future of UTC
Tony: The book is available at my local library - I'll check it out with an open mind, but I just can't see what would be the difference of telling people they need to go to work 1hr earlier instead of 'fooling' them by changing their clocks. Wikipedia has a long article, too - it seems the original justification (power savings) hasn't been realized. Thanks, Jose -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tony Finch Sent: Monday, July 18, 2011 5:24 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC Jose Camara camar...@quantacorp.com wrote: I think before adding to the fire of UTC1, UTC7 etc. why not just abolish this silliness called Daylight Savings Time? If there is any benefit to it, just change business operating hours instead. If you want to know why your suggestion doesn't work, David Prerau has collected many many examples. http://www.seizethedaylight.com/ Tony. -- f.anthony.n.finch d...@dotat.at http://dotat.at/ Fair Isle: Northerly or northeasterly 4 or 5 increasing 5 or 6, but 6 or 7 in far west at first. Moderate or rough. Rain or showers. Moderate or poor. ___ 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] The future of UTC
At 08:23 AM 7/18/2011, Tony Finch wrote... If you want to know why your suggestion doesn't work, David Prerau has collected many many examples. http://www.seizethedaylight.com/ Nope. Not much there but an advertisement. ___ 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] The future of UTC
Jose, In many countries, the government has no right to tell companies when they should be open or closed. However, they control when midnight is. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Jose Camara camar...@quantacorp.com Sender: time-nuts-boun...@febo.com Date: Mon, 18 Jul 2011 07:28:39 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] The future of UTC Tony: The book is available at my local library - I'll check it out with an open mind, but I just can't see what would be the difference of telling people they need to go to work 1hr earlier instead of 'fooling' them by changing their clocks. Wikipedia has a long article, too - it seems the original justification (power savings) hasn't been realized. Thanks, Jose -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tony Finch Sent: Monday, July 18, 2011 5:24 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC Jose Camara camar...@quantacorp.com wrote: I think before adding to the fire of UTC1, UTC7 etc. why not just abolish this silliness called Daylight Savings Time? If there is any benefit to it, just change business operating hours instead. If you want to know why your suggestion doesn't work, David Prerau has collected many many examples. http://www.seizethedaylight.com/ Tony. -- f.anthony.n.finch d...@dotat.at http://dotat.at/ Fair Isle: Northerly or northeasterly 4 or 5 increasing 5 or 6, but 6 or 7 in far west at first. Moderate or rough. Rain or showers. Moderate or poor. ___ 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.
Re: [time-nuts] The future of UTC
In Detroit, Michigan, when the auto manufacturing companies discovered that having everyone's shift starting at 8 AM caused huge traffic problems, companies chose non-rounded times. For example, one company starts their shift at 7:40 AM, another starts at 7:25, and so on. This was done without government intervention, just an intelligent choice. If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? On 07/18/2011 11:49 AM, shali...@gmail.com wrote: Jose, In many countries, the government has no right to tell companies when they should be open or closed. However, they control when midnight is. Didier KO4BB ___ 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] The future of UTC
On Mon, Jul 18, 2011 at 9:06 AM, Mike Naruta AA8K a...@comcast.net wrote: If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? The amount of time to move the clock depends on how far north you live. Days being even longer at high latitudes. I think one hour is a compromise. There have been proposals to do what they call double daylight saving time -- Chris Albertson Redondo Beach, California ___ 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] Rb cooling
Hi Yes, I have seen several Rb's die from what I believe were temperature related causes. Since it's an accelerated MTBF sort of thing, *proving* they were temperature related is difficult. Put another way - I believe the manufacturer's data on MTBF vs temperature is fairly accurate. At elevated temperatures, the life of the device is in the few years (2 to 4) range. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chuck Harris Sent: Monday, July 18, 2011 12:00 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Rb cooling For all of this attention to cooling the oven on the Rb standards, has anyone seen any failures that are attributable to heat? I sort of doubt it. -Chuck Harris ewkeh...@aol.com wrote: I monitor and fan cool the base plate, stays nice and constant at 45 C which I can not say with heat sink only. I am considering lowering the base plate to 40 C. I have a heat sink on the base plate with the fan blowing over it. Makes good heat exchanger. I have experimented with heat pipes from Lap Tops but never fit for mechanical reasons. May work with a LPRO's. Al my Rb's are Efratom. A variable speed fan will reduce any ambient temperature influence. That is why I chose to use a fan. Use a dual Op Amp for temp. control. Nothing special. Fans are $ 3.00 I have monitored points inside the Rb's and they are within 1 C over time. Bert Kehren ___ 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] The future of UTC
I believe we had double daylight saving over here (UK) during WWII. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: 18 July 2011 5:17 PM To: a...@comcast.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC On Mon, Jul 18, 2011 at 9:06 AM, Mike Naruta AA8K a...@comcast.net wrote: If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? The amount of time to move the clock depends on how far north you live. Days being even longer at high latitudes. I think one hour is a compromise. There have been proposals to do what they call double daylight saving time -- Chris Albertson Redondo Beach, California ___ 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] The future of UTC
If you keep going farther from the equator, than it makes no sense after a while. Above the Artic Circle, when you get 24hrs of daylight, what is the need? And when you get no daylight in a day, should you wake up at sunrise? I just don't agree that the government has to step in and 'make sluggards wake up early'. What if the sluggards and drunks would honk their horns at 1am to get more people to party at the bars? :-) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Monday, July 18, 2011 9:17 AM To: a...@comcast.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC On Mon, Jul 18, 2011 at 9:06 AM, Mike Naruta AA8K a...@comcast.net wrote: If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? The amount of time to move the clock depends on how far north you live. Days being even longer at high latitudes. I think one hour is a compromise. There have been proposals to do what they call double daylight saving time -- Chris Albertson Redondo Beach, California ___ 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] The future of UTC
Hi Rob from memory it was referred to as Double Summer Time .looking at my very wet window we should be so lucky!! :-)) Alan G3NYK - Original Message - From: Rob Kimberley r...@timing-consultants.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Monday, July 18, 2011 5:49 PM Subject: Re: [time-nuts] The future of UTC I believe we had double daylight saving over here (UK) during WWII. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: 18 July 2011 5:17 PM To: a...@comcast.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC On Mon, Jul 18, 2011 at 9:06 AM, Mike Naruta AA8K a...@comcast.net wrote: If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? The amount of time to move the clock depends on how far north you live. Days being even longer at high latitudes. I think one hour is a compromise. There have been proposals to do what they call double daylight saving time -- Chris Albertson Redondo Beach, California ___ 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.
Re: [time-nuts] The future of UTC
I just don't see why we need to save daylight; don't we have enough already? Is that not part of the cause of the alleged global warming? And how does shifting the clock by an hour actually save any daylight? OK, so to get slightly more serious, the best argument pushed here in Ohio is that in the winter months, school aged kids aren't walking to school or waiting for the bus in the dark. In the summer months, it isn't an issue. Of course, DST isn't in effect in the winter months, so I still don't get it. And why do they keep extending the DST season? We only have ST between mid November to mid March now. It was once late April to early October. Someone somewhere is making some money off of this scam. Tom Holmes, N8ZM Tipp City, OH EM79 -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jose Camara Sent: Monday, July 18, 2011 1:05 PM To: 'Discussion of precise time and frequency measurement'; a...@comcast.net Subject: Re: [time-nuts] The future of UTC If you keep going farther from the equator, than it makes no sense after a while. Above the Artic Circle, when you get 24hrs of daylight, what is the need? And when you get no daylight in a day, should you wake up at sunrise? I just don't agree that the government has to step in and 'make sluggards wake up early'. What if the sluggards and drunks would honk their horns at 1am to get more people to party at the bars? :-) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Monday, July 18, 2011 9:17 AM To: a...@comcast.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC On Mon, Jul 18, 2011 at 9:06 AM, Mike Naruta AA8K a...@comcast.net wrote: If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? The amount of time to move the clock depends on how far north you live. Days being even longer at high latitudes. I think one hour is a compromise. There have been proposals to do what they call double daylight saving time -- Chris Albertson Redondo Beach, California ___ 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.
Re: [time-nuts] The future of UTC
Hi Alan, I de-anglicised it for our cousins across the water! :-) -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Alan Melia Sent: 18 July 2011 6:15 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC Hi Rob from memory it was referred to as Double Summer Time .looking at my very wet window we should be so lucky!! :-)) Alan G3NYK - Original Message - From: Rob Kimberley r...@timing-consultants.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Monday, July 18, 2011 5:49 PM Subject: Re: [time-nuts] The future of UTC I believe we had double daylight saving over here (UK) during WWII. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: 18 July 2011 5:17 PM To: a...@comcast.net; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] The future of UTC On Mon, Jul 18, 2011 at 9:06 AM, Mike Naruta AA8K a...@comcast.net wrote: If advancing the clocks one hour saves so much daylight, why not advance the clocks by two hours to save even more? The amount of time to move the clock depends on how far north you live. Days being even longer at high latitudes. I think one hour is a compromise. There have been proposals to do what they call double daylight saving time -- Chris Albertson Redondo Beach, California ___ 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 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] The future of UTC
On 18 Jul 2011, at 05:23 , Tony Finch wrote: Jose Camara camar...@quantacorp.com wrote: I think before adding to the fire of UTC1, UTC7 etc. why not just abolish this silliness called Daylight Savings Time? If there is any benefit to it, just change business operating hours instead. If you want to know why your suggestion doesn't work, David Prerau has collected many many examples. http://www.seizethedaylight.com/ Yet most of the people on the planet live in a place where DST is not observed now, and that includes people living as far north as 65 degrees latitude and as far south as 55 degrees. Should they all be told this doesn't work? Dennis Ferguson ___ 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] The future of UTC
On Jul 18, 2011, at 3:02 PM, Tom Holmes wrote: Someone somewhere is making some money off of this [DST] scam. From an NPR interview with Michael Downing, author of Spring Forward: The Annual Madness of Daylight Saving Time http://www.npr.org/templates/story/story.php?storyId=7779869 Mr. DOWNING: Well, because when we have an hour of sunlight after work, Americans tend to go shopping. The first and most persistent lobby for Daylight Saving in this country was the Chamber of Commerce, because they understood that if their department stores were lit up, people would be tempted by them. In 1986, Congress gave us an extra month of Daylight Saving Time. That's when we went from six to seven months, which is the period we've been living with recently. In that congressional hearings, the golf industry alone - these are the industry estimates - told Congress one additional month of daylight saving was worth $200 million in additional sales of golf clubs and greens fees. The barbecue industry said it was worth $100 million in additional sales of grills and charcoal briquettes. BLOCK: This may be kind of an urban legend, but I thought I had heard that one of the backers behind extending Daylight Saving Time into the beginning of November was the candy industry, and it all had to do with Halloween. Mr. DOWNING: This is no kind of legend. This is the truth. For 25 years, candy-makers have wanted to get trick-or-treat covered by Daylight Saving, figuring that if children have an extra hour of daylight, they'll collect more candy. In fact, they went so far during the 1985 hearings on Daylight Saving as to put candy pumpkins on the seat of every senator, hoping to win a little favor. Best regards, -Steve -- Steve Byan steveb...@me.com Littleton, MA 01460 ___ 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] TBolt question
Hello! I would be most grateful for expanded info about the Lady Heather red message: OSC age alarm Thanks in advance, Antonio CT1TE ___ 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] TBolt question
On Tue, Jul 19, 2011 at 02:48:29AM +0200, asma...@fc.up.pt wrote: I would be most grateful for expanded info about the Lady Heather red message: OSC age alarm Sounds to me like it's at the edge of (or even outside of) DAC tuning range. i.e. the Thunderbolt may not be able to discipline the oscillator correctly. What's the DAC voltage? --msa ___ 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.
