Re: [time-nuts] Question for the cesium nuts.
On Fri, 23 Mar 2007 23:29:43 -0700, Hal Murray [EMAIL PROTECTED] wrote: My digital camera died recently. (Well, it was killed. I gave it a bath in salt water when I miss-judged a wave at the ocean.) I went to the local brick and mortar camera store to get a replacement. After I told the guy what I was interested in, he brought out several possibilities. He dropped one of them on the floor from normal hand/chest height. It was still working after he picked it up. I forget the brand, but somebody was willing to put their reputation on the line. Any other grey beard here ever see HP's calculator promotional show that they staged on campuses? The one where the rep hurled Brand T or C against the wall and of course, it splattered. Then he hurls an HP-35 or -45 the same way and it just bounces a little and keeps right on working. I left one of those demonstrations with an HP-45 in my pocket and my wallet $495 lighter. Still have it and it still works just fine even after being drowned by a tidal wave of split-pea soup from a burst thermos John --- John De Armond See my website for my current email address http://www.neon-john.com Cleveland, Occupied TN All great things are simple and many can be expressed in single words: Freedom, Justice, Honor, Duty, Mercy, Hope. -Churchill ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
The Nikonos, a fine instrument. The line still exists. Didier KO4BB Joseph Gray wrote: Back in the days of cameras that used film :-) Nikon used to make a very nice waterproof and rugged camera. I forgot the model, but it was made for divers. I knew several people who had one, but they were all cavers. Needless to say, these cameras took a lot of abuse in a cave. - Original Message - From: Hal Murray [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 24, 2007 12:29 AM Subject: Re: [time-nuts] Question for the cesium nuts. My digital camera died recently. (Well, it was killed. I gave it a bath in salt water when I miss-judged a wave at the ocean.) I went to the local brick and mortar camera store to get a replacement. After I told the guy what I was interested in, he brought out several possibilities. He dropped one of them on the floor from normal hand/chest height. It was still working after he picked it up. I forget the brand, but somebody was willing to put their reputation on the line. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In message [EMAIL PROTECTED], Neon John writes: Any other grey beard here ever see HP's calculator promotional show that they staged on campuses? The one where the rep hurled Brand T or C against the wall and of course, it splattered. Then he hurls an HP-35 or -45 the same way and it just bounces a little and keeps right on working. Best demo ever was the Grid Tempest laptops. They'd throw them out of 2nd floor windows, run them over with their cars, pour coffee into them (if you use more than two lumps of sugar or cream, you should rinse so it will not start to smell) Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
It exists the same way many old cesiums exists. I think Nikon still supports the line with spares and support. No new units produced. Killed in the high end now by UW-housed DSLRs and inte the low end by UW-housed compact digital cameras. Nikon never made a digital Nikonos. -- Björn On Sat, March 24, 2007 14:50, Didier Juges said: The Nikonos, a fine instrument. The line still exists. Didier KO4BB Joseph Gray wrote: Back in the days of cameras that used film :-) Nikon used to make a very nice waterproof and rugged camera. I forgot the model, but it was made for divers. I knew several people who had one, but they were all cavers. Needless to say, these cameras took a lot of abuse in a cave. - Original Message - From: Hal Murray [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 24, 2007 12:29 AM Subject: Re: [time-nuts] Question for the cesium nuts. My digital camera died recently. (Well, it was killed. I gave it a bath in salt water when I miss-judged a wave at the ocean.) I went to the local brick and mortar camera store to get a replacement. After I told the guy what I was interested in, he brought out several possibilities. He dropped one of them on the floor from normal hand/chest height. It was still working after he picked it up. I forget the brand, but somebody was willing to put their reputation on the line. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
A couple of years ago my wife dropped her digital camera in a parking lot at a wedding we were attending. The camera would turn on, but it complained that there was no memory card. When we got back home, I opened it up to find that a surface mount dual transistor that controls power to the memory card had come loose. I thought it strange that this was the problem, considering how rugged SM usually is. After a lot of research, I was able to find out what the part was and get a replacement. (NOT, of course from the camera manufacturer.. they would only sell me the completed board at a cost exceeding the price I had originally paid for the entire camera!). Works fine again now. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray Sent: Saturday, March 24, 2007 2:30 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. That reminds me of a tester I got to see while I was working on a project for Motorola at one of their ALT (accelerated life test) labs. This was for testing durability of cell phones. The tester basically was a pendulum that was about three feet high. At the base, you placed the PUT (phone under test), and you pulled the pendulum up to a specified angle and let it go. It would swing down and whack the phone across the room into a target. Amazing what they'll handle! My digital camera died recently. (Well, it was killed. I gave it a bath in salt water when I miss-judged a wave at the ocean.) I went to the local brick and mortar camera store to get a replacement. After I told the guy what I was interested in, he brought out several possibilities. He dropped one of them on the floor from normal hand/chest height. It was still working after he picked it up. I forget the brand, but somebody was willing to put their reputation on the line. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Your camera probably had a cold solder joint. Maybe it was an RoHS part soldered with standard soldering process. We have that problem all the time with vendors sending RoHS parts with the same part number as the SnPb part they replace. I would not be surprised to see a lot of those problems in the future. I got lucky once also with an extremely compact hand held radio I got off eBay cheap (was broken). A couple of SM parts were damaged, much smaller than the SM parts we use where I work. However, I was able to get the spare voltage regulator from Icom, and I replaced a diode with an SOT-23 part I had. The SOT-23 was so much larger than the part I was replacing, it would not fit on the pads and I had to jumper it in... The jumper wire was bigger than the part I was replacing. Under the microscope, it looked like there was lots of room :-) No coffee for me that morning! Didier KO4BB Daun Yeagley wrote: A couple of years ago my wife dropped her digital camera in a parking lot at a wedding we were attending. The camera would turn on, but it complained that there was no memory card. When we got back home, I opened it up to find that a surface mount dual transistor that controls power to the memory card had come loose. I thought it strange that this was the problem, considering how rugged SM usually is. After a lot of research, I was able to find out what the part was and get a replacement. (NOT, of course from the camera manufacturer.. they would only sell me the completed board at a cost exceeding the price I had originally paid for the entire camera!). Works fine again now. Daun ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
On Sat, 24 Mar 2007 15:39:15 +0100 (CET), [EMAIL PROTECTED] wrote: It exists the same way many old cesiums exists. I think Nikon still supports the line with spares and support. No new units produced. Killed in the high end now by UW-housed DSLRs and inte the low end by UW-housed compact digital cameras. Nikon never made a digital Nikonos. -- Björn UW-housed It isn't clicking for me (unintentional pun). What do you mean by UW? Couldn't be microwave. I'm guessing some kind of plactic. On Sat, March 24, 2007 14:50, Didier Juges said: The Nikonos, a fine instrument. The line still exists. Didier KO4BB ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Rex wrote: On Sat, 24 Mar 2007 15:39:15 +0100 (CET), [EMAIL PROTECTED] wrote: It exists the same way many old cesiums exists. I think Nikon still supports the line with spares and support. No new units produced. Killed in the high end now by UW-housed DSLRs and inte the low end by UW-housed compact digital cameras. Nikon never made a digital Nikonos. -- Björn UW-housed It isn't clicking for me (unintentional pun). What do you mean by UW? Couldn't be microwave. I'm guessing some kind of plactic. Under Water housed ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
That reminds me of a tester I got to see while I was working on a project for Motorola at one of their ALT (accelerated life test) labs. This was for testing durability of cell phones. The tester basically was a pendulum that was about three feet high. At the base, you placed the PUT (phone under test), and you pulled the pendulum up to a specified angle and let it go. It would swing down and whack the phone across the room into a target. Amazing what they'll handle! My digital camera died recently. (Well, it was killed. I gave it a bath in salt water when I miss-judged a wave at the ocean.) I went to the local brick and mortar camera store to get a replacement. After I told the guy what I was interested in, he brought out several possibilities. He dropped one of them on the floor from normal hand/chest height. It was still working after he picked it up. I forget the brand, but somebody was willing to put their reputation on the line. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Back in the days of cameras that used film :-) Nikon used to make a very nice waterproof and rugged camera. I forgot the model, but it was made for divers. I knew several people who had one, but they were all cavers. Needless to say, these cameras took a lot of abuse in a cave. - Original Message - From: Hal Murray [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, March 24, 2007 12:29 AM Subject: Re: [time-nuts] Question for the cesium nuts. My digital camera died recently. (Well, it was killed. I gave it a bath in salt water when I miss-judged a wave at the ocean.) I went to the local brick and mortar camera store to get a replacement. After I told the guy what I was interested in, he brought out several possibilities. He dropped one of them on the floor from normal hand/chest height. It was still working after he picked it up. I forget the brand, but somebody was willing to put their reputation on the line. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Hi, I think you would find it surprising what is still restricted. While searching for data on the FTS/Datron/Symmetricom 1000B I discovered that Datron/Symmetricom got hammered for trying to export a couple of OXCO's to India. I can't find the link at the moment but they settled at $35,000. A lot of telecom stuff like fibre coupled lasers are still restricted so are some capacitors (low inductance high current) and trigger devices. I friend of mine had a visit from the US authorities (we are in the UK) for listing a modern military whip antenna on eBay. Robert. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray Sent: 18 March 2007 04:56 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. Are there some funny accounting rules screwing things up? Not accounting rules as you meant them, but rather end use rules. It takes someone with a functioning brain to figure out what the different pieces of equipment are, and to make sure that the end use restrictions are honored. It is far easier to drive over the stuff with a dozer, and render it inert than it is to propagate the necessary paper chain... or so the DRMO says. I'm still somewhat (but not very) surprised that they aren't outsourcing the whole mess or something like that. I assume end use rules means don't send fancy gear to Iran and North Korea etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Genetix Limited - Queensway, New Milton, Hampshire, BH25 5NN Registered in England No. 2660050 www.genetix.com Any opinions expressed in this email are those of the individual and not necessarily Genetix Ltd (Genetix) or any company associated with it. This email and any files transmitted with it are confidential and solely for the use of the intended recipient. If you are not the intended recipient or the person responsible for delivering to the intended recipient, be advised that you have received this email in error and that any use is strictly prohibited. If you have received this email in error please notify Genetix by telephone on +44 (0)1425 624600. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving Genetix network. Genetix will not be liable for direct, special, indirect or consequential damages as a result of any virus being passed on, or arising from alteration of the contents of this message by a third party. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Hi Again Hal, There are standards for de-militarisation, you used to be able to download manuals on it from the LOGSA web site but they seem to have closed up that information source :-( I remember a couple of examples, when they sold Jeeps in the UK for scrap you had to either cut them diagonally corner to corner through all major components or crush them completely with a tracked vehicle before they left the site. Apparently the local tracked vehicle drivers were usually happy to oblige. For aircraft the standard was to cut through the fuselage in two places or through each main wing spar. Allegedly the reason there are so many F86 Sabre's still flying is that one disposal site cut only the wings and another cut only the fuselage! Robert. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray Sent: 18 March 2007 06:36 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. To pass the hammer blow test, the unit has to still function electrically after the blow. It is OK if it suffers structural damage as long as it still works. That's an interesting corner of the world that I've never worked with. Is there an official test spec for destroying gear? :( Something like how big a bulldozer you have to crush it with. Google finds references to a barge test, and things like this: http://www.aplabs.com/about/newsarchives/bftt.html http://www.racksolutions.com/rugged/hammer-test.shtml -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Genetix Limited - Queensway, New Milton, Hampshire, BH25 5NN Registered in England No. 2660050 www.genetix.com Any opinions expressed in this email are those of the individual and not necessarily Genetix Ltd (Genetix) or any company associated with it. This email and any files transmitted with it are confidential and solely for the use of the intended recipient. If you are not the intended recipient or the person responsible for delivering to the intended recipient, be advised that you have received this email in error and that any use is strictly prohibited. If you have received this email in error please notify Genetix by telephone on +44 (0)1425 624600. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving Genetix network. Genetix will not be liable for direct, special, indirect or consequential damages as a result of any virus being passed on, or arising from alteration of the contents of this message by a third party. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Hi Brooke, I notice that Murphy's Surplus in San Diego now specify NO exports of any item! I guess mike has had a warning. Robert. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brooke Clarke Sent: 18 March 2007 18:59 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. Hi Hal: I got a couple of Austron 2100T Loran-C timing receivers from Government Liquidation (the private contractor that sells most of the U.S. Government's surplus stuff). Some time later someone drove hundreds of miles and stayed at a local motel so he could come to my place and see each one that I bought or get the name and address of who I sold it to. If you have something that might be on a list that should not be exported there's no easy way to find out. There's no web page, or hard copy document to check against. If you're in the U.S. and deal with military surplus it would be very difficult to export anything without spending a lot of time figuring out if it was allowed or not allowed. If you did spend the time there would be no profit left or the price would be very high. Have Fun, Brooke Clarke w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com Hal Murray wrote: I assume end use rules means don't send fancy gear to Iran and North Korea etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Genetix Limited - Queensway, New Milton, Hampshire, BH25 5NN Registered in England No. 2660050 www.genetix.com Any opinions expressed in this email are those of the individual and not necessarily Genetix Ltd (Genetix) or any company associated with it. This email and any files transmitted with it are confidential and solely for the use of the intended recipient. If you are not the intended recipient or the person responsible for delivering to the intended recipient, be advised that you have received this email in error and that any use is strictly prohibited. If you have received this email in error please notify Genetix by telephone on +44 (0)1425 624600. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving Genetix network. Genetix will not be liable for direct, special, indirect or consequential damages as a result of any virus being passed on, or arising from alteration of the contents of this message by a third party. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Interesting.. Thought India was OK, and OCXOs are usually fine as unrestricted. Even Rb or Cs should have been OK with an End User statement. Maybe the Indian customer was selling on to somewhere restricted (not unheard of!!) Rob -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Atkinson Sent: 19 March 2007 09:10 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. Hi, I think you would find it surprising what is still restricted. While searching for data on the FTS/Datron/Symmetricom 1000B I discovered that Datron/Symmetricom got hammered for trying to export a couple of OXCO's to India. I can't find the link at the moment but they settled at $35,000. A lot of telecom stuff like fibre coupled lasers are still restricted so are some capacitors (low inductance high current) and trigger devices. I friend of mine had a visit from the US authorities (we are in the UK) for listing a modern military whip antenna on eBay. Robert. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray Sent: 18 March 2007 04:56 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. Are there some funny accounting rules screwing things up? Not accounting rules as you meant them, but rather end use rules. It takes someone with a functioning brain to figure out what the different pieces of equipment are, and to make sure that the end use restrictions are honored. It is far easier to drive over the stuff with a dozer, and render it inert than it is to propagate the necessary paper chain... or so the DRMO says. I'm still somewhat (but not very) surprised that they aren't outsourcing the whole mess or something like that. I assume end use rules means don't send fancy gear to Iran and North Korea etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Genetix Limited - Queensway, New Milton, Hampshire, BH25 5NN Registered in England No. 2660050 www.genetix.com Any opinions expressed in this email are those of the individual and not necessarily Genetix Ltd (Genetix) or any company associated with it. This email and any files transmitted with it are confidential and solely for the use of the intended recipient. If you are not the intended recipient or the person responsible for delivering to the intended recipient, be advised that you have received this email in error and that any use is strictly prohibited. If you have received this email in error please notify Genetix by telephone on +44 (0)1425 624600. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving Genetix network. Genetix will not be liable for direct, special, indirect or consequential damages as a result of any virus being passed on, or arising from alteration of the contents of this message by a third party. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Hal Murray wrote: Are there some funny accounting rules screwing things up? Not accounting rules as you meant them, but rather end use rules. It takes someone with a functioning brain to figure out what the different pieces of equipment are, and to make sure that the end use restrictions are honored. It is far easier to drive over the stuff with a dozer, and render it inert than it is to propagate the necessary paper chain... or so the DRMO says. I'm still somewhat (but not very) surprised that they aren't outsourcing the whole mess or something like that. They tried that during Clinton, and the companies that did the work didn't do the work. They were less efficient than DRMO was in the first place... of course by the time they found that out, all of the original guys that did the work for DRMO were fired, retired, or reassigned. I assume end use rules means don't send fancy gear to Iran and North Korea Yes, that is the general idea. Also medical equipment must not be used by the US medical community in the US, hazardous materials must sold only to companies that are proven capable of safe use and disposal, vehicles must not be sold in a way that competes with commercial companies (HumVee's, etc.), airplanes must not be sold in a way that competes with Boing... etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. That works fine if you assume that the US Gov't only surpluses a few hundred different items. The the truth is they surplus hundreds of thousands of different items. Everything from Apple Computers to Zebra shaped figurines. Imagine what would happen if a 0.01 uf capacitor appeared in the inventory as: Capacitor, 0.01 uf Capacitor, 0.01MFD Capacitor, 10nf Condenser, 0.01 uf Condenser, 0.01MFD Condenser, 0.01 MFD Condenser, 0.01 MF Condenser, 10nf Cap, 0.01uf Cap, 0.01MFD Cap, 10nf Electronic Component, Condenser, 0.01 microfarad... It does, and worse, there are spelling errors too! Most every item in the DRMO inventory appears multiple times. Each time a little different, depending on how the clerk who entered it thought to describe it. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. Motivated??? What are you talking about? The real work gets done by warehousemen that drive forklifts. These guys are GS5's, and get paid just a little bit above minimum wage. They are too dumb to be motivated, let alone give a rats ass about what they are doing. Electronic equipment is just metal boxes to them. -Chuck ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Hi Hal: I got a couple of Austron 2100T Loran-C timing receivers from Government Liquidation (the private contractor that sells most of the U.S. Government's surplus stuff). Some time later someone drove hundreds of miles and stayed at a local motel so he could come to my place and see each one that I bought or get the name and address of who I sold it to. If you have something that might be on a list that should not be exported there's no easy way to find out. There's no web page, or hard copy document to check against. If you're in the U.S. and deal with military surplus it would be very difficult to export anything without spending a lot of time figuring out if it was allowed or not allowed. If you did spend the time there would be no profit left or the price would be very high. Have Fun, Brooke Clarke w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com Hal Murray wrote: I assume end use rules means don't send fancy gear to Iran and North Korea etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In a message dated 3/17/2007 07:40:07 Pacific Daylight Time, [EMAIL PROTECTED] writes: Reminds me of the extra-ordinary light bulb: http://www.centennialbulb.org/ /tvb This bulb has burned about 3714 Kilowatthours or so of power so far, or 3.7 Megawattshours! That's impressive. bye, Said ** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In a message dated 3/18/2007 06:29:32 Pacific Daylight Time, [EMAIL PROTECTED] writes: Yes, that is the general idea. Also medical equipment must not be used by the US medical community in the US, hazardous materials must sold only to companies that are proven capable of safe use and disposal, vehicles must not be sold in a way that competes with commercial companies (HumVee's, etc.), airplanes must not be sold in a way that competes with Boing... Here is the real reason I think: competition. I heard in the early 70's they destroyed the old Appollo era blue-prints real quickly so that there won't be any competition to the Space Shuttle program; this appearantly gave Werner von Braun almost a heart attack. 2 decades later they wished they had these blue-prints... About a year ago there was an RFQ by the government to destroy 10's of thousands of aircraft parked somewhere in Arizona by the highest bidder. No one was allowed to remove any equipment or spare parts from these aircraft. We gotta keep the military industrial complex allive! bye, Said ** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
http://www.kvarz.com/pdf/05%20CH1-75A.pdf (Active MASER) http://www.kvarz.com/pdf/06%20CH1-76A.pdf (Passive MASER) What do active and passive mean wrt masers? From the above data sheets, active means bigger and better. (and probably more expensive) -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Hal Murray wrote: http://www.kvarz.com/pdf/05%20CH1-75A.pdf (Active MASER) http://www.kvarz.com/pdf/06%20CH1-76A.pdf (Passive MASER) What do active and passive mean wrt masers? From the above data sheets, active means bigger and better. (and probably more expensive) Hal Active masers oscillate. Passive masers don't. Bruce ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
What do active and passive mean wrt masers? From the above data sheets, active means bigger and better. (and probably more expensive) Hal Active masers oscillate. Passive masers don't. Bruce Another way to think about it: active masers oscillate; passive masers resonate. Note the rubidium vapor and cesium beam atomic frequency standards that many of us use are also of the passive type; i.e., they lock a quartz LO by rapid probing of the resonance frequency. /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Having worked on the HP 10816A rubidium clock 25 years ago, it is hard for my to believe the lamp alone could last 56 years on the average. Even ordinary light bulbs don't last that long. Rick Karlquist N6RK [EMAIL PROTECTED] wrote: In a message dated 3/16/2007 18:32:58 Pacific Daylight Time, [EMAIL PROTECTED] writes: Also, some high end rubidium (such as Perkin-Elmer) manufacturers are able to develope 133Rb clocks having 450 000 hours MTBF! That'a a lot of nanoseconds! Hi Jack, we cannot expect the units to work that long. Hard Disks have 50K MTBF, and fail all the time in much less time depending on how they are used etc. MTBF is a mean, meaning in the real world the Perkin Elmer unit could fail in the first 10 minutes, just that the statistics for that to happen have pretty low probability. When they calculate MTBF, they probably don't take into account external effects such as AC voltage spikes due to janitors pluggin-in vacuum's or due to lightning etc, earthquakes, user obuse, water damage, movement, effects of UV light on plastik parts such as cables, Tin Whisker shorts, electrolytic capacitor dryout, mouse damage, etc. I think it's pretty useless to say a piece of equipment has a MTBF of over 50 years. Then again that's only an opinion... bye, Said ** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Actually, it was the lawyers and fear of lawsuits that prompted the change. Better safe than sorry, besides, it's not their money they waste anyway. Need more, call Congress !! 73, Dick, W1KSZ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Hal Murray Sent: Friday, March 16, 2007 10:12 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. Well, there is one reason, and that is the US DRMO discovered it is cheaper to destroy test equipment than it is to sell it. Is that really true? I'd think a reseller would buy stuff by the truckload without much hassle and that would avoid carting it to the dump. Are there some funny accounting rules screwing things up? Are there security considerations? Can they still toss stuff in the dump? Will green regulations raise the cost of destroying gear enough so that it's cheaper to sell it? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Having worked on the HP 10816A rubidium clock 25 years ago, it is hard for my to believe the lamp alone could last 56 years on the average. Even ordinary light bulbs don't last that long. Rick Karlquist N6RK Reminds me of the extra-ordinary light bulb: http://www.centennialbulb.org/ /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
From: Dr Bruce Griffiths [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Sat, 17 Mar 2007 22:06:40 +1300 Message-ID: [EMAIL PROTECTED] Hal, To put a few more words on each of them. Active masers oscillate. Active masers will actually generate an RF signal on its own. This signal is then used to lock up a 5 or 10 MHz OCXO typically. Passive masers don't. Passive masers acts like a very narrow filter which you need to interrigate by applying your generated RF signal and then figure out where to control your 5 or 10 MHz OCXO which is used to generate the RF signal. Not very different from the use of a crystal in the feedback loop of a XO. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
I believe the deal on that bulb is that it is being run at considerably less than its normal voltage, and the life of a bulb varies as voltage to the Nth power, where N is an integer around -12 or something. Like those lifetime 130V bulbs. Unfortunately, you can't throttle down a Rb plasma lamp. Rick Karlquist N6RK Tom Van Baak wrote: Having worked on the HP 10816A rubidium clock 25 years ago, it is hard for my to believe the lamp alone could last 56 years on the average. Even ordinary light bulbs don't last that long. Rick Karlquist N6RK Reminds me of the extra-ordinary light bulb: http://www.centennialbulb.org/ /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Am I the only one who have never heard of the 10816A before ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
From: Poul-Henning Kamp [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Sat, 17 Mar 2007 17:09:37 + Message-ID: [EMAIL PROTECTED] Am I the only one who have never heard of the 10816A before ? A google for HP 10816A did not exactly turn up much. Except that it does exist and works. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
That project made it as far as a pilot run of a half dozen working prototypes and assignment of a model number, but HP never sold any of them. I still have one of these valuable collector's items :-) You probably never heard of the HP 5063 cesium either, but that's another story... Rick Karlquist N6RK Poul-Henning Kamp wrote: Am I the only one who have never heard of the 10816A before ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
You're thinking of the 5062 that fits into the hatch of a submarine (a 5061 won't). The test is called the hammer blow test. Rick Karlquist N6RK Magnus Danielson wrote: From: Rick Karlquist [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Sat, 17 Mar 2007 13:48:11 -0700 (PDT) Message-ID: [EMAIL PROTECTED] Rick, That project made it as far as a pilot run of a half dozen working prototypes and assignment of a model number, but HP never sold any of them. I still have one of these valuable collector's items :-) You probably never heard of the HP 5063 cesium either, but that's another story... Isn't that the Navy cesium? To handle the physical shocks of the big 12 inch canons if I recall correctly. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
From: Rick Karlquist [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Sat, 17 Mar 2007 15:29:38 -0700 (PDT) Message-ID: [EMAIL PROTECTED] You're thinking of the 5062 that fits into the hatch of a submarine (a 5061 won't). Ah, thanks for recharging my neurons on that one. The test is called the hammer blow test. Why do I picture a large steel hammer on a swing setup with a DUT as targeted endpoint? OK, so what was the 5063 then? Now that you got us hooked! Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
The test is called the hammer blow test. Why do I picture a large steel hammer on a swing setup with a DUT as targeted endpoint? Because that's pretty much how it's done :-) OK, the DUT is sitting on a big steel table and the hammer hits the table not the piece, but still...you would be amazed at how far the pieces fly sometimes. Tom Frank, KA2CDK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
That reminds me of a tester I got to see while I was working on a project for Motorola at one of their ALT (accelerated life test) labs. This was for testing durability of cell phones. The tester basically was a pendulum that was about three feet high. At the base, you placed the PUT (phone under test), and you pulled the pendulum up to a specified angle and let it go. It would swing down and whack the phone across the room into a target. Amazing what they'll handle! Another similar test was dropping a steel ball (maybe 3/4 diameter) onto the display of the phone. The idea was to see how high you could go before it shattered. One of my more amusing projects. Daun -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Thomas A. Frank Sent: Saturday, March 17, 2007 9:41 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. The test is called the hammer blow test. Why do I picture a large steel hammer on a swing setup with a DUT as targeted endpoint? Because that's pretty much how it's done :-) OK, the DUT is sitting on a big steel table and the hammer hits the table not the piece, but still...you would be amazed at how far the pieces fly sometimes. Tom Frank, KA2CDK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
To pass the hammer blow test, the unit has to still function electrically after the blow. It is OK if it suffers structural damage as long as it still works. Rick Karlquist N6RK OK, the DUT is sitting on a big steel table and the hammer hits the table not the piece, but still...you would be amazed at how far the pieces fly sometimes. Tom Frank, KA2CDK ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Are there some funny accounting rules screwing things up? Not accounting rules as you meant them, but rather end use rules. It takes someone with a functioning brain to figure out what the different pieces of equipment are, and to make sure that the end use restrictions are honored. It is far easier to drive over the stuff with a dozer, and render it inert than it is to propagate the necessary paper chain... or so the DRMO says. I'm still somewhat (but not very) surprised that they aren't outsourcing the whole mess or something like that. I assume end use rules means don't send fancy gear to Iran and North Korea etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Follow the money. Every piece of DRMO equipment sold is a piece of equipment that wasn't bought commercially. With companies being merged and acquired, wealth concentrates to where buying congresscritters doesn't show on the bottom line. IMHO. Bill Hawkins -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hal Murray Sent: Saturday, March 17, 2007 11:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. Are there some funny accounting rules screwing things up? Not accounting rules as you meant them, but rather end use rules. It takes someone with a functioning brain to figure out what the different pieces of equipment are, and to make sure that the end use restrictions are honored. It is far easier to drive over the stuff with a dozer, and render it inert than it is to propagate the necessary paper chain... or so the DRMO says. I'm still somewhat (but not very) surprised that they aren't outsourcing the whole mess or something like that. I assume end use rules means don't send fancy gear to Iran and North Korea etc. Is there a simple list of what is/isn't OK to ship to anybody? If a box sells for $100, it can't be a big deal to have somebody check each item against a known-OK list. If the penalties are real nasty, check it twice. The stuff you can't ship to bad guys is probably worth more so they would be motivated to find it. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
To pass the hammer blow test, the unit has to still function electrically after the blow. It is OK if it suffers structural damage as long as it still works. That's an interesting corner of the world that I've never worked with. Is there an official test spec for destroying gear? :( Something like how big a bulldozer you have to crush it with. Google finds references to a barge test, and things like this: http://www.aplabs.com/about/newsarchives/bftt.html http://www.racksolutions.com/rugged/hammer-test.shtml -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
What are we going to do when all the CBTs owned by amateurs start to end of life? Buy another instrument off of Ebay. It'll be cheaper, more accurate, and last longer than the old one. Plus, it'll have microprocessor control and thus be cooler and more entertaining for the hackers. Anyone care to start a discussion on the merits of restoring a CBT to life? It can't be done. Trust me, I've done it. -RL -- Robert Lutwak, Senior Scientist Symmetricom - Technology Realization Center 34 Tozer Rd. Beverly, MA 01915 [EMAIL PROTECTED] (Business) [EMAIL PROTECTED] (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (FAX) -- Original message -- From: Jack Hudler [EMAIL PROTECTED] It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Let me try to remember some of the answers to this question that I heard from the cesium guys (I was only the RF guy on the 5071A, so I know just enough about cesium to be dangerous :-) The tubes rarely if ever fail because they run out of cesium. Sometimes they fail because the electron multiplier wears out. Other times that have a soft failure where they get noisier and noisier. This is possibly due to gradual build up of contaminants. Sometimes the ion pump will get overwhelmed. If you were to open up a tube, you would find that all the components are cesiated. Of course there is no way to clean them up. Thus you cannot recycle tube components. If you made a tube with cesiated components, it would probably be noisy and or not hold a good vacuum. You would have to fix whatever broke in the first place, in addition to replacing the cesium. You would of course have to replace the cesium whether it was used up or not because it will burn up as soon as the vacuum is broken. I am not sure that the cesium oven lends itself to disassembly and reassembly. Also, I think you would have to remove the wiring harness before bake out and reinstall it, because of the high temperatures involved. Rick Karlquist N6RK Jack Hudler wrote: It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Which begs the question of; who's cesium standard will we buy in surplus market? Besides you guys (Symmetricom), who is building Cesium standards that haven't yet been absorbed by Symmetricom? (note this is not meant to be derogatory). Certainly most if not all the 5060, 5061, and 5062 are either dead or close to it. Excluding those that have had their CBT's replaced or properly stored and regularly pumped down, or just lucky. The 5071's have yet to make an appearance on eBay at levels I would consider paying. From my POV (which could be myopic), a few CBT manufacturers are controlling what remains of this market (no I'm not a conspiracy nut, it's just business), so it seems to me that the surplus market is going to get very thin in the near future. Supply and demand dictates that surplus market prices will skyrocket out of the vast majority of amateur reaches in the coming years. So what's the next cesium standard to start showing up on eBay in numbers with life left? Jack -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Friday, March 16, 2007 12:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. What are we going to do when all the CBTs owned by amateurs start to end of life? Buy another instrument off of Ebay. It'll be cheaper, more accurate, and last longer than the old one. Plus, it'll have microprocessor control and thus be cooler and more entertaining for the hackers. Anyone care to start a discussion on the merits of restoring a CBT to life? It can't be done. Trust me, I've done it. -RL -- Robert Lutwak, Senior Scientist Symmetricom - Technology Realization Center 34 Tozer Rd. Beverly, MA 01915 [EMAIL PROTECTED] (Business) [EMAIL PROTECTED] (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (FAX) -- Original message -- From: Jack Hudler [EMAIL PROTECTED] It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Jack, You bring up a good point, but... The Cesium atoms make a one-way trip from one end of the tube the other; from a nice solid/liquid pool of silvery cesium in the oven to a splattered mess in the getter. So there's no restoring the tube that once that's done. Think toothpaste. Think ballpoint pen. Think taxes. True, some tubes will last 20 years or more; and that's with continuous use. If you only turn on the Cs once a week or once a month to re-calibrate the excellent low-drift internal OCXO inside your frequency standard then it will likely live longer than you will. So it sort of depends on how you use your valuable instrument. I had nice pictures of the insides of a modern cesium tube on my web site but was asked to remove them. But it's not like the atoms make a nice trip from point A to point B and when they are all at point B you simply wipe clean point B and reload point A. You can open a dud cesium tube without too much worry. Any elemental cesium is still frozen in the oven. The rest has been sucked up in the getter or is painted all over the EM or magnets. Safe enough to handle (well, then again, as many of you, I played with mercury as a kid). As for time value of money, consider that owning, or having access to, precise time is simply a service and you get what you pay for. For example, if you want time to the hour it is free -- look up at the sun. If you want time to the minute, well just peek at anyone's watch for free. Ah, you want time to the second; you might need to own a very good wrist watch, a cell phone, or computer, or a WWVB RC clock. Still not good enough? Expect to pay more for milliseconds. Even more for microseconds; a GPS time/frequency receiver perhaps. Nanoseconds? That's the realm of a cesium clock. Those of us that really get into the hobby realize that time is money: each digit of accuracy costs you another digit of budget. /tvb http://www.LeapSecond.com - Original Message - From: Jack Hudler [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Friday, March 16, 2007 09:26 Subject: [time-nuts] Question for the cesium nuts. It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
From: Jack Hudler [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Fri, 16 Mar 2007 13:25:47 -0500 Message-ID: [EMAIL PROTECTED] Which begs the question of; who's cesium standard will we buy in surplus market? Besides you guys (Symmetricom), who is building Cesium standards that haven't yet been absorbed by Symmetricom? (note this is not meant to be derogatory). Oscilloquartz. I beleive that they have Symmetricom tubes in them. Actually that would raise questions regarding to second-source for serious telecom operators. Fortunatly for them, GPS clocks is usually enought. I beleive there was a Russian Cesium-maker, but if I recall correctly they stopped doing Cesium clocks. From my POV (which could be myopic), a few CBT manufacturers are controlling what remains of this market (no I'm not a conspiracy nut, it's just business), so it seems to me that the surplus market is going to get very thin in the near future. It is really just buisness decissions behind it. Weither they where wise or not is another issue. Joint buissnesses is not always beneficial (see second-source comment). Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
The only people I know making Cs now are Symmetricom (the old Datum/FTS + recent Agilent acquisition), FEI (although they don't think they make many now), and Temex in France. Heard rumours of some being made in Japan, but not sure if and who. The Russians seem to concentrate on H2 Masers (Kvarz, and Vremya). Anyone know of others?? Rob K -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Hudler Sent: 16 March 2007 18:26 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Question for the cesium nuts. Which begs the question of; who's cesium standard will we buy in surplus market? Besides you guys (Symmetricom), who is building Cesium standards that haven't yet been absorbed by Symmetricom? (note this is not meant to be derogatory). Certainly most if not all the 5060, 5061, and 5062 are either dead or close to it. Excluding those that have had their CBT's replaced or properly stored and regularly pumped down, or just lucky. The 5071's have yet to make an appearance on eBay at levels I would consider paying. From my POV (which could be myopic), a few CBT manufacturers are controlling what remains of this market (no I'm not a conspiracy nut, it's just business), so it seems to me that the surplus market is going to get very thin in the near future. Supply and demand dictates that surplus market prices will skyrocket out of the vast majority of amateur reaches in the coming years. So what's the next cesium standard to start showing up on eBay in numbers with life left? Jack -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Friday, March 16, 2007 12:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. What are we going to do when all the CBTs owned by amateurs start to end of life? Buy another instrument off of Ebay. It'll be cheaper, more accurate, and last longer than the old one. Plus, it'll have microprocessor control and thus be cooler and more entertaining for the hackers. Anyone care to start a discussion on the merits of restoring a CBT to life? It can't be done. Trust me, I've done it. -RL -- Robert Lutwak, Senior Scientist Symmetricom - Technology Realization Center 34 Tozer Rd. Beverly, MA 01915 [EMAIL PROTECTED] (Business) [EMAIL PROTECTED] (Personal) (978) 232-1461 (Desk) (339) 927-7896 (Mobile) (978) 927-4099 (FAX) -- Original message -- From: Jack Hudler [EMAIL PROTECTED] It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
The Russians seem to concentrate on H2 Masers (Kvarz, and Vremya). Maybe we don't have to worry about cesium lifetime. What are the alternatives? When will H2 Masers be affordable on eBay? ... -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
From: Rob Kimberley [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Fri, 16 Mar 2007 21:44:52 - Message-ID: ![EMAIL PROTECTED] Interesting question!! Don't think we'll see an H2 MASER on EBay, as just too expensive, plus only a few made each year. Rather large beasts - see the link below, and installed commissioned by manufacturer on site. The active ones are in the $150K - $200K price range new, passive ones less. Symmetricom also make one - the old Sigma Tau company down in in Alabama which FTS/Datum bought. I was involved in bidding a Russian one last year in the UK. http://www.kvarz.com/pdf/05%20CH1-75A.pdf (Active MASER) http://www.kvarz.com/pdf/06%20CH1-76A.pdf (Passive MASER) for further reading. Oscilloquartz introduced a passive maser fairly recently. They also had an active going I beleive, but I don't think it has hit the market yeat. Observatoir Neuchatel also makes masers, but active ones. Again, there isn't as many makes of physical packages as there is of clocks. There have been reports in frequency shift due to shifts in humidity and that this differs between the models available on the market. I don't have any hard data at hand to support this thought. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
What about rubidium standards? Are they more common due to lower price? Speaking of which, Ebay has several Rubidium atomic clock smallest cell frequency standard listed for US$20. What are these modules? LtCol Keith E. Brandt, MD, MPH USAF-NASA Aerospace Medicine Liaison Officer Johnson Space Center, Houston, Texas [EMAIL PROTECTED] Goodbye cruel world that was my home- there's cleaner space out here to roam Put my feet up on the moons of Mars- sit back, relax, and count the stars *This message transmitted with 100% recycled electrons ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Much more common. We're talking tens of thousands of these manufactured against a few hundred Caesium (Cesium) standards, and a handful of MASERS in a year, so priced accordingly. Just looked at the item on EBay. This is the physics package from a Rb standard including the Rb cell. It would need the electronics, oscillator and PSU wrapping round it to become a Rb standard. Try Item Number 290093161408 for a complete unit. Kind Regards Rob Kimberley -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Keith E. Brandt, M.D. Sent: 16 March 2007 22:01 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. What about rubidium standards? Are they more common due to lower price? Speaking of which, Ebay has several Rubidium atomic clock smallest cell frequency standard listed for US$20. What are these modules? LtCol Keith E. Brandt, MD, MPH USAF-NASA Aerospace Medicine Liaison Officer Johnson Space Center, Houston, Texas [EMAIL PROTECTED] Goodbye cruel world that was my home- there's cleaner space out here to roam Put my feet up on the moons of Mars- sit back, relax, and count the stars *This message transmitted with 100% recycled electrons ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
There's no reason that you shouldn't see just as many CsIIIs, Cs4000s, and 5071s on the used market tomorrow as you see 4040s and 506Xs today, just as soon as they trickle down through the same channels as the older units did. So far, of the modern cesium standards, I've only seen a few 5071s on the used market, and they're still priced pretty high, but I'm certain the others will trickle down before long. Eventually, they'll be dirt cheap, because a new CsIII costs half of what a 4040 did when new. They'll be more accurate, for reasons that you can read about in 15 years of FCS proceedings, and they'll be more reliable because of 15 years of electronics evolution and manufacturing improvements. Oh, and they'll be more fun, because you'll be able to run Monitor3. :-) -RL - Original Message - From: Jack Hudler [EMAIL PROTECTED] To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Friday, March 16, 2007 2:25 PM Subject: Re: [time-nuts] Question for the cesium nuts. Which begs the question of; who's cesium standard will we buy in surplus market? Besides you guys (Symmetricom), who is building Cesium standards that haven't yet been absorbed by Symmetricom? (note this is not meant to be derogatory). Certainly most if not all the 5060, 5061, and 5062 are either dead or close to it. Excluding those that have had their CBT's replaced or properly stored and regularly pumped down, or just lucky. The 5071's have yet to make an appearance on eBay at levels I would consider paying. From my POV (which could be myopic), a few CBT manufacturers are controlling what remains of this market (no I'm not a conspiracy nut, it's just business), so it seems to me that the surplus market is going to get very thin in the near future. Supply and demand dictates that surplus market prices will skyrocket out of the vast majority of amateur reaches in the coming years. So what's the next cesium standard to start showing up on eBay in numbers with life left? Jack -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Friday, March 16, 2007 12:56 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Question for the cesium nuts. What are we going to do when all the CBTs owned by amateurs start to end of life? Buy another instrument off of Ebay. It'll be cheaper, more accurate, and last longer than the old one. Plus, it'll have microprocessor control and thus be cooler and more entertaining for the hackers. Anyone care to start a discussion on the merits of restoring a CBT to life? It can't be done. Trust me, I've done it. -RL -- Original message -- From: Jack Hudler [EMAIL PROTECTED] It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
From: Robert Lutwak [EMAIL PROTECTED] Subject: Re: [time-nuts] Question for the cesium nuts. Date: Fri, 16 Mar 2007 18:09:43 -0400 Message-ID: [EMAIL PROTECTED] Robert, There's no reason that you shouldn't see just as many CsIIIs, Cs4000s, and 5071s on the used market tomorrow as you see 4040s and 506Xs today, just as soon as they trickle down through the same channels as the older units did. Good point! So far, of the modern cesium standards, I've only seen a few 5071s on the used market, and they're still priced pretty high, but I'm certain the others will trickle down before long. Most seems to be left-overs from closed labs etc. as far as I have seen. Eventually, they'll be dirt cheap, because a new CsIII costs half of what a 4040 did when new. They'll be more accurate, for reasons that you can read about in 15 years of FCS proceedings, and they'll be more reliable because of 15 years of electronics evolution and manufacturing improvements. Good points. Very good points. Thanks for pointing it out. Kind of obvious, but you need to recall the obvious at times. Oh, and they'll be more fun, because you'll be able to run Monitor3. :-) Indeed. I enjoy doing that. Hmm, which reminds me, I should do something about setting up a continous logging from my Linux box. Hmm... there is alot of continous loggings I should be setting up. Time, time... so much to do and so little time to do it on. Sigh! Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Robert Lutwak wrote: There's no reason that you shouldn't see just as many CsIIIs, Cs4000s, and 5071s on the used market tomorrow as you see 4040s and 506Xs today, just as soon as they trickle down through the same channels as the older units did. Well, there is one reason, and that is the US DRMO discovered it is cheaper to destroy test equipment than it is to sell it. So, I doubt we will ever again see the vast supply of surplus electronics that came from the cold war ramping down. -Chuck Harris ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In message: [EMAIL PROTECTED] Chuck Harris [EMAIL PROTECTED] writes: : Robert Lutwak wrote: : There's no reason that you shouldn't see just as many CsIIIs, Cs4000s, and : 5071s on the used market tomorrow as you see 4040s and 506Xs today, just as : soon as they trickle down through the same channels as the older units did. : : Well, there is one reason, and that is the US DRMO discovered it is cheaper : to destroy test equipment than it is to sell it. So, I doubt we will ever : again see the vast supply of surplus electronics that came from the cold war : ramping down. /me wonders how it is cheaper to destory a $25k clock than to sell it... Warner ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In a message dated 3/16/2007 11:34:56 Pacific Daylight Time, [EMAIL PROTECTED] writes: The Cesium atoms make a one-way trip from one end of the tube the other; from a nice solid/liquid pool of silvery cesium in the oven to a splattered mess in the getter. So there's no restoring the tube that once that's done. Think toothpaste. Think ballpoint pen. Think taxes. Hi Tom, I have a used FTS-4050 unit that has a very high Cs current (meter is maxed) and generally doesen't seem to lock very well. Is there anyone in the market for a used FTS-4050 for parts? I would be interested to sell the actual Cs reference inside the unit. Want to keep the 19 rack mount enclosure though. The unit has a good 5MHz OCXO (modell FTS1200 I think), and of course there are all the Cs control boards inside which are probably still good. The OCXO makes this a nice parts unit. Wanted to see if anyone is interested in trading etc, otherwise I may put it on Ebay. bye, Said ** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Jack Hudler [EMAIL PROTECTED] wrote: Which begs the question of; who's cesium standard will we buy in surplus market? From my POV (which could be myopic), a few CBT manufacturers are controlling what remains of this market (no I'm not a conspiracy nut, it's just business), so it seems to me that the surplus market is going to get very thin in the near future. Supply and demand dictates that surplus market prices will skyrocket out of the vast majority of amateur reaches in the coming years. So what's the next cesium standard to start showing up on eBay in numbers with life left? The last big boom in CBT and other timing equipment was the telecom boom of the late 90's, and when it went pop (actually even before) a lot of almost new stuff hit the surplus stream big-time. The telecom boom-bust cycle there will not be repeated in quite the same way and I cannot imagine doing it to the same scale, where startup telcos and equipment manufacturers could get funding to get hundreds of millions of dollars equipment made without any paying customers :-). The next big thing may not be cesium standards, might be something else, but it'll probably be tied to some other boom-bust cycle in some tech/business sector. Each boom-bust cycle will not be exacltly like the one before, the cold-war military/avionics stuff I grew up with is probably never going to happen again either. Nor are the R-390A's piled to the sky, nor are the command sets by the thousands, but in reality none of that stuff is particularly hard to come by. I just picked up a couple of command sets that had been sitting in a guy's garage for 40 years and are exactly like they were when he got them! Tim. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Perhaps the future of timing is the newly developed (and not yet commercialized) Mercury ion frequency standard. Also, some high end rubidium (such as Perkin-Elmer) manufacturers are able to develope 133Rb clocks having 450 000 hours MTBF! That'a a lot of nanoseconds! 73 de Normand VE2UM --- Jack Hudler [EMAIL PROTECTED] wrote: It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
Well, there is one reason, and that is the US DRMO discovered it is cheaper to destroy test equipment than it is to sell it. Is that really true? I'd think a reseller would buy stuff by the truckload without much hassle and that would avoid carting it to the dump. Are there some funny accounting rules screwing things up? Are there security considerations? Can they still toss stuff in the dump? Will green regulations raise the cost of destroying gear enough so that it's cheaper to sell it? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In a message dated 3/16/2007 18:32:58 Pacific Daylight Time, [EMAIL PROTECTED] writes: Also, some high end rubidium (such as Perkin-Elmer) manufacturers are able to develope 133Rb clocks having 450 000 hours MTBF! That'a a lot of nanoseconds! Hi Jack, we cannot expect the units to work that long. Hard Disks have 50K MTBF, and fail all the time in much less time depending on how they are used etc. MTBF is a mean, meaning in the real world the Perkin Elmer unit could fail in the first 10 minutes, just that the statistics for that to happen have pretty low probability. When they calculate MTBF, they probably don't take into account external effects such as AC voltage spikes due to janitors pluggin-in vacuum's or due to lightning etc, earthquakes, user obuse, water damage, movement, effects of UV light on plastik parts such as cables, Tin Whisker shorts, electrolytic capacitor dryout, mouse damage, etc. I think it's pretty useless to say a piece of equipment has a MTBF of over 50 years. Then again that's only an opinion... bye, Said ** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
I have a used FTS-4050 unit that has a very high Cs current (meter is maxed) and generally doesen't seem to lock very well. Is there anyone in the market for a used FTS-4050 for parts? I would be interested to sell the actual Cs reference inside the unit. Want to keep the 19 rack mount enclosure though. I'm interested, if the price is reasonable, as I have a 4050 that has some life left to it. I'm just down the street from you; I'm in Los Gatos. -ch ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Question for the cesium nuts.
In a message dated 3/16/2007 20:37:28 Pacific Daylight Time, [EMAIL PROTECTED] writes: Is there anyone in the market for a used FTS-4050 for parts? I would be interested to sell the actual Cs reference inside the unit. Want to keep the 19 rack mount enclosure though. I'm interested, if the price is reasonable, as I have a 4050 that has some life left to it. I'm just down the street from you; I'm in Los Gatos. -ch Hi Ch, I'm looking to trade with maybe a monetary compensation from my side to you. I'm presently looking for a good frequency counter, 620, CNT90, 5370B type of quality. bye, Said ** AOL now offers free email to everyone. Find out more about what's free from AOL at http://www.aol.com. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
