Re: [time-nuts] beryllium oxide
Many high power TWT's (traveling wave tubes) use it at the collector end, for thermal coupling to the baseplate, or heat disipator. They will be marked up accordingly, with a BeO sticker, or a Do not cut open warning. Also, some high power RF semiconductors use it, though many modern examples use alumina ceramic. (I think that's what it's called.) We have several scrap TWT's and Buckets of scrap QRO semi's here at the salt mine, that we just can't dispose of as a result. Thankfully, they don't take up much space. Regards. Dave Baxter. --Original Message Message: 10 Date: Fri, 31 Jul 2009 22:41:17 +0100 From: Dr. David Kirkby david.kir...@onetel.net Subject: Re: [time-nuts] beryllium oxide To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4a7364fd.9020...@onetel.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Dr. David Kirkby wrote: Marco IK1ODO wrote: Robert, Some power tubesmay use it internally. As far as I know, from many discussions with power tube manufacturers, no power tube uses beryllia, except for that conduction-cooled Eimac tubes. It's simply not needed. Other tubes (not power ones) may be different, but I never heard of any beryllia in them. Marco IK1ODO / AI4YF I believe some of the bases for the conduction cooled tubes use BeO too. I might be wrong on this. I have a few sitting in the garage somewhere. I doubt there is any point having it inside air/water/vapor cooled tubes Sorry, just realised I replied to something written ages ago. -- winmail.dat___ 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] beryllium oxide
The british military marking for BeO is a pale blue color. Normally a paint spot but I've seen insulators that were tinted blue. Robert G8RPI. --- On Sat, 1/8/09, Dave Baxter d...@uk-ar.co.uk wrote: From: Dave Baxter d...@uk-ar.co.uk Subject: Re: [time-nuts] beryllium oxide To: time-nuts@febo.com Date: Saturday, 1 August, 2009, 7:24 PM Many high power TWT's (traveling wave tubes) use it at the collector end, for thermal coupling to the baseplate, or heat disipator. They will be marked up accordingly, with a BeO sticker, or a Do not cut open warning. Also, some high power RF semiconductors use it, though many modern examples use alumina ceramic. (I think that's what it's called.) We have several scrap TWT's and Buckets of scrap QRO semi's here at the salt mine, that we just can't dispose of as a result. Thankfully, they don't take up much space. Regards. Dave Baxter. --Original Message Message: 10 Date: Fri, 31 Jul 2009 22:41:17 +0100 From: Dr. David Kirkby david.kir...@onetel.net Subject: Re: [time-nuts] beryllium oxide To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4a7364fd.9020...@onetel.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Dr. David Kirkby wrote: Marco IK1ODO wrote: Robert, Some power tubesmay use it internally. As far as I know, from many discussions with power tube manufacturers, no power tube uses beryllia, except for that conduction-cooled Eimac tubes. It's simply not needed. Other tubes (not power ones) may be different, but I never heard of any beryllia in them. Marco IK1ODO / AI4YF I believe some of the bases for the conduction cooled tubes use BeO too. I might be wrong on this. I have a few sitting in the garage somewhere. I doubt there is any point having it inside air/water/vapor cooled tubes Sorry, just realised I replied to something written ages ago. -- -Inline Attachment Follows- ___ 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] beryllium oxide
Marco IK1ODO wrote: Robert, Some power tubesmay use it internally. As far as I know, from many discussions with power tube manufacturers, no power tube uses beryllia, except for that conduction-cooled Eimac tubes. It's simply not needed. Other tubes (not power ones) may be different, but I never heard of any beryllia in them. Marco IK1ODO / AI4YF I believe some of the bases for the conduction cooled tubes use BeO too. I might be wrong on this. I have a few sitting in the garage somewhere. I doubt there is any point having it inside air/water/vapor cooled tubes ___ 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] beryllium oxide
Dr. David Kirkby wrote: Marco IK1ODO wrote: Robert, Some power tubesmay use it internally. As far as I know, from many discussions with power tube manufacturers, no power tube uses beryllia, except for that conduction-cooled Eimac tubes. It's simply not needed. Other tubes (not power ones) may be different, but I never heard of any beryllia in them. Marco IK1ODO / AI4YF I believe some of the bases for the conduction cooled tubes use BeO too. I might be wrong on this. I have a few sitting in the garage somewhere. I doubt there is any point having it inside air/water/vapor cooled tubes Sorry, just realised I replied to something written ages ago. ___ 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] beryllium oxide
At 12:22 PM 1/16/2009, Robert Darlington wrote... Beryliosis. That's a glib response, which says nothing to contradict Brooke's point. ___ 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] beryllium oxide
More realistically, the dangeris dust when something is physically overstressed (dropped, mounting overtightened, thermal shock). That, and if it gets ground up in trash disposal... Say someone throws it in the shredder. -Original Message- From: Mike S mi...@flatsurface.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Cc: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: 1/16/09 09:41 Subject: Re: [time-nuts] beryllium oxide At 12:22 PM 1/16/2009, Robert Darlington wrote... Beryliosis. That's a glib response, which says nothing to contradict Brooke's point. ___ 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] beryllium oxide
Beryliosis. The problem that I'm familiar with is dust made when machining beryllium. In the 60s, MIT had a whole building that was full of the stuff leftover from machining parts for the Polaris guidance system. Beryllium is light and stiff, good for making gyros. Beryllium oxide is a ceramic similar to aluminum oxide. I expect it's being used as an insulator with good thermal conductivity. I'd expect that to be safe. There might be troubles if you break it or grind it. (It would probably ignore sandpaper.) From an AAVID web page: http://www.aavidthermalloy.com/products/standard/access/beryllium.shtml Beryllium oxide is chemically inert and completely safe to use in its fired state. Handling of finished parts presents absolutely no health hazards. Beryllium oxide,however, is toxic when dust, mist or fumes containing particles small enough to enter the lungs are inhaled. Therefore, grindings, sanding, and pulverizing the material should be avoided. -- Max temp is 2149C/3900F. I guess it won't have any troubles in OXCOs. :) -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] beryllium oxide
At 12:45 PM 1/16/2009, Lux, James P wrote... More realistically, the dangeris dust when something is physically overstressed (dropped, mounting overtightened, thermal shock). That, and if it gets ground up in trash disposal... Say someone throws it in the shredder. So, if some electronics have an IC with a BeO package, and it sits undisturbed, what's the problem? It seems to me that most, if not all, such uses would be additionally contained by heatsinks and compound, since it's the thermal conductivity properties which caused it to be used in the first place. Hard to say how much dust might be produced by dropping or overtightening. In my experience, ceramics tend to break pretty cleanly. Maybe BeO is different. Granted, the manufacturer can be expected to be biased, but Brush Ceramics claims Beryllium oxide (BeO), in solid form and as contained in finished products, presents no special health risks. They also claim Under federal regulations and most state regulations, BeO ceramic or products containing BeO ceramics that are no longer recyclable and declared solid wastes are not classified as hazardous waste due the content of BeO ceramic. ___ 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] beryllium oxide
I've personally seen three applications of BeO in electronics. Two, including the most common, are a possible hazzard. The most common application is RF power devices (transistors and terminating resistors). These hace a washer or slab of BeO between the semiconductor device and the mounting stud or flange. Asthis is trypically below the electrical connecting leads (often wide strips or tabs), application of excessive force between heatsink and PCB can fracture the BeO causing dust an chips/splinters. Splinters onder the skin or in the eye can cause problems as well as inhaled dust. force can be applied during manufacture / service or in an accident or if the item containing the unit is crushed. Next most common is the use in metal can semiconductors. One example are early LM78Hxx TO3 regulators. These are fairly safe as the can has to be ruptured. The third is as a block of solid BeO bonded to metal plates used to insulate conduction cooled vacuum tubes. Some power tubesmay use it internally. A big problem is that it looks like any other ceramic. In some UK equipment devices containing BeO will be marked with cornflower blue paint dot. A non-electronic application is in some (eg argon-ion) lasers. on a side note some vacuum tubes (especially cold cathode types) contain various radioactive materials. Robert G8RPI. --- On Fri, 16/1/09, Mike S mi...@flatsurface.com wrote: From: Mike S mi...@flatsurface.com Subject: Re: [time-nuts] beryllium oxide To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Friday, 16 January, 2009, 6:28 PM At 12:45 PM 1/16/2009, Lux, James P wrote... More realistically, the dangeris dust when something is physically overstressed (dropped, mounting overtightened, thermal shock). That, and if it gets ground up in trash disposal... Say someone throws it in the shredder. So, if some electronics have an IC with a BeO package, and it sits undisturbed, what's the problem? It seems to me that most, if not all, such uses would be additionally contained by heatsinks and compound, since it's the thermal conductivity properties which caused it to be used in the first place. Hard to say how much dust might be produced by dropping or overtightening. In my experience, ceramics tend to break pretty cleanly. Maybe BeO is different. Granted, the manufacturer can be expected to be biased, but Brush Ceramics claims Beryllium oxide (BeO), in solid form and as contained in finished products, presents no special health risks. They also claim Under federal regulations and most state regulations, BeO ceramic or products containing BeO ceramics that are no longer recyclable and declared solid wastes are not classified as hazardous waste due the content of BeO ceramic. ___ 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] beryllium oxide
Robert Atkinson wrote: non-electronic application is in some (eg argon-ion) lasers. on a side note some vacuum tubes (especially cold cathode types) contain various radioactive materials. Robert G8RPI. Of interest to time nuts is that rubidium standards contain two isotopes of Rb, one of which is slightly radioactive. Also, if you have an Rb in your basement and it starts acting squirrely, it might be because you have helium in the air, since helium gets into hermetic stuff. If you do have helium, it is because you have radon, which radiates helium ions, also known as alpha particles. Rick N6RK ___ 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] beryllium oxide
Rick Karlquist wrote: Robert Atkinson wrote: non-electronic application is in some (eg argon-ion) lasers. on a side note some vacuum tubes (especially cold cathode types) contain various radioactive materials. Robert G8RPI. Of interest to time nuts is that rubidium standards contain two isotopes of Rb, one of which is slightly radioactive. Also, if you have an Rb in your basement and it starts acting squirrely, it might be because you have helium in the air, since helium gets into hermetic stuff. If you do have helium, it is because you have radon, which radiates helium ions, also known as alpha particles. Rick N6RK Radon diffuses up through the ground. The radon is a daughter product from natural radioactive decay processes within the Earth. In some areas it is considered good practice to have good ventilation in basements and under the floor to disperse the radon that would otherwise accumulate. There is some epidemiological evidence for enhanced cancer rates when radon concentration is high. The problem isn't the radon itself but its decay products Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
Since we're on the subject, what does BeO typically look like when it's used as a washer, heatsink, etc. I ask because I tend to keep everything and I modify things all the time. Is there any way besides being painted that it could pass as Al? -Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
Robert Atkinson wrote: I've personally seen three applications of BeO in electronics. Two, including the most common, are a possible hazzard. The most common application is RF power devices (transistors and terminating resistors). These hace a washer or slab of BeO between the semiconductor device and the mounting stud or flange. Asthis is trypically below the electrical connecting leads (often wide strips or tabs), application of excessive force between heatsink and PCB can fracture the BeO causing dust an chips/splinters. Splinters onder the skin or in the eye can cause problems as well as inhaled dust. force can be applied during manufacture / service or in an accident or if the item containing the unit is crushed. Next most common is the use in metal can semiconductors. One example are early LM78Hxx TO3 regulators. These are fairly safe as the can has to be ruptured. The third is as a block of solid BeO bonded to metal plates used to insulate conduction cooled vacuum tubes. Some power tubesmay use it internally. A big problem is that it looks like any other ceramic. In some UK equipment devices containing BeO will be marked with cornflower blue paint dot. A non-electronic application is in some (eg argon-ion) lasers. on a side note some vacuum tubes (especially cold cathode types) contain various radioactive materials. Robert G8RPI. --- On Fri, 16/1/09, Mike S mi...@flatsurface.com wrote: From: Mike S mi...@flatsurface.com Subject: Re: [time-nuts] beryllium oxide To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Friday, 16 January, 2009, 6:28 PM At 12:45 PM 1/16/2009, Lux, James P wrote... More realistically, the dangeris dust when something is physically overstressed (dropped, mounting overtightened, thermal shock). That, and if it gets ground up in trash disposal... Say someone throws it in the shredder. So, if some electronics have an IC with a BeO package, and it sits undisturbed, what's the problem? It seems to me that most, if not all, such uses would be additionally contained by heatsinks and compound, since it's the thermal conductivity properties which caused it to be used in the first place. Hard to say how much dust might be produced by dropping or overtightening. In my experience, ceramics tend to break pretty cleanly. Maybe BeO is different. Granted, the manufacturer can be expected to be biased, but Brush Ceramics claims Beryllium oxide (BeO), in solid form and as contained in finished products, presents no special health risks. They also claim Under federal regulations and most state regulations, BeO ceramic or products containing BeO ceramics that are no longer recyclable and declared solid wastes are not classified as hazardous waste due the content of BeO ceramic. The OCXO in question doesn't have the usual foam insulation that is easily removed, but has cast in place insulation of somewhat higher density. Its impossible to remove without cutting or dissolving, and there is no easy way to know if beryllia powder was used selectively as a thermal conduction enhancement additive rather than beryllia sheets were used internally within semiconductor packages or as thermally conductive washers. I have no data on the pin connections or any other specs. It appears to be a General Radio 1158-4010 with 7 teflon insulated feedthrough insulators. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
BeO furthermore had been used in some types of RF attenuators, especially for higher power, as a insulating washer for transistors (High voltage power transistors, RF terminating resistors, Thermal studs and so on. Although it is replaced nowadays in most cases by different materials, Beo can be found easily in older equipment. Hubert DB 7 ME -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Robert Atkinson Gesendet: Freitag, 16. Januar 2009 19:59 An: Discussion of precise time and frequency measurement Betreff: [!! SPAM] Re: [time-nuts] beryllium oxide I've personally seen three applications of BeO in electronics. Two, including the most common, are a possible hazzard. The most common application is RF power devices (transistors and terminating resistors). These hace a washer or slab of BeO between the semiconductor device and the mounting stud or flange. Asthis is trypically below the electrical connecting leads (often wide strips or tabs), application of excessive force between heatsink and PCB can fracture the BeO causing dust an chips/splinters. Splinters onder the skin or in the eye can cause problems as well as inhaled dust. force can be applied during manufacture / service or in an accident or if the item containing the unit is crushed. Next most common is the use in metal can semiconductors. One example are early LM78Hxx TO3 regulators. These are fairly safe as the can has to be ruptured. The third is as a block of solid BeO bonded to metal plates used to insulate conduction cooled vacuum tubes. Some power tubesmay use it internally. A big problem is that it looks like any other ceramic. In some UK equipment devices containing BeO will be marked with cornflower blue paint dot. A non-electronic application is in some (eg argon-ion) lasers. on a side note some vacuum tubes (especially cold cathode types) contain various radioactive materials. Robert G8RPI. --- On Fri, 16/1/09, Mike S mi...@flatsurface.com wrote: From: Mike S mi...@flatsurface.com Subject: Re: [time-nuts] beryllium oxide To: Discussion of precise time and frequency measurement time-nuts@febo.com Date: Friday, 16 January, 2009, 6:28 PM At 12:45 PM 1/16/2009, Lux, James P wrote... More realistically, the dangeris dust when something is physically overstressed (dropped, mounting overtightened, thermal shock). That, and if it gets ground up in trash disposal... Say someone throws it in the shredder. So, if some electronics have an IC with a BeO package, and it sits undisturbed, what's the problem? It seems to me that most, if not all, such uses would be additionally contained by heatsinks and compound, since it's the thermal conductivity properties which caused it to be used in the first place. Hard to say how much dust might be produced by dropping or overtightening. In my experience, ceramics tend to break pretty cleanly. Maybe BeO is different. Granted, the manufacturer can be expected to be biased, but Brush Ceramics claims Beryllium oxide (BeO), in solid form and as contained in finished products, presents no special health risks. They also claim Under federal regulations and most state regulations, BeO ceramic or products containing BeO ceramics that are no longer recyclable and declared solid wastes are not classified as hazardous waste due the content of BeO ceramic. ___ 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] beryllium oxide
Robert, Some power tubesmay use it internally. As far as I know, from many discussions with power tube manufacturers, no power tube uses beryllia, except for that conduction-cooled Eimac tubes. It's simply not needed. Other tubes (not power ones) may be different, but I never heard of any beryllia in them. Marco IK1ODO / AI4YF ___ 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] beryllium oxide
At 20.41 16/01/2009, you wrote: Since we're on the subject, what does BeO typically look like when it's used as a washer, heatsink, etc. I ask because I tend to keep everything and I modify things all the time. Is there any way besides being painted that it could pass as Al? -Dave Exactly as Al. White, hard ceramic. May be colored, but also allumina may be pink or violet (see Russian power tubes). Marco IK1ODO ___ 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] beryllium oxide
d.sei...@comcast.net wrote: Since we're on the subject, what does BeO typically look like when it's used as a washer, heatsink, etc. I ask because I tend to keep everything and I modify things all the time. Is there any way besides being painted that it could pass as Al? -Dave Dave, It's a white ceramic substance. Commonly used on the older pill shaped RF power transistors. ___ 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] beryllium oxide
d.sei...@comcast.net wrote: Since we're on the subject, what does BeO typically look like when it's used as a washer, heatsink, etc. I ask because I tend to keep everything and I modify things all the time. Is there any way besides being painted that it could pass as Al? -Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Dave The TO3 beryllia washers I have are light blue, but pure beryllia is white. Various ionic impurities can be used to impart different colours to the final product. Pure Alumina is also white but pink TO3 alumina washers are/were available. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
Mark Sims skrev: Three other places one may encounter beryllium are: 1) Beryllium copper springs and contacts, usually around 2-3% beryllium. Not likely to cause a problem unless you get your jollies grinding up springy metal and snorting the powder. 2) Beryllium tools! Tools (particularly screwdrivers and pliers) can be made out of pure beryllium metal. They are not magnetic, very strong, very light. They were used a lot in aerospace and military applications. One thing that used to appear on the surplus market was an EOD toolkit used by bomb disposal techs. Even had a beryllium hammer. These were wonderful tools which you might just find when clearing out old uncle Bob's estate... 3) Nuclear reactors and weapons. Be careful when disassembling that surplus nuke you picked up on your last trip to eastern Europe... Oh... where did I put that pile of junk? :- Beryllium was originally called glucinium becuase it and its salts tasted very sweet. In fact, tasting used to be a diagnostic test for the presence of beryllium. Sounds dangerous... I have encountered Beryllium in a field none of you mentioned, as material for speaker cones. Light and very rigid. Perfect for the top driver for horns. I recall something about high speed of sound. 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] beryllium oxide
In message 4970e72d.1050...@rubidium.dyndns.org, Magnus Danielson writes: I have encountered Beryllium in a field none of you mentioned, as material for speaker cones. Light and very rigid. Perfect for the top driver for horns. I recall something about high speed of sound. It is also used for mirrors for certain, usually classified, applications. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | 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 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
In message 22975.1232136...@critter.freebsd.dk, Poul-Henning Kamp writes: It is also used for mirrors for certain, usually classified, applications. Actually, isn't the James Webb space telescope using a Be mirror now that I think about it ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | 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 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
Also used on old lighthouse tubes used for uhf and low microwave applications fro the '40's and '50's. If my memory serves me, these tubes were found in devices like the airborne APX-6 IFF Transponder in which the greatest hazard was the detonators used to destroy the device should a plane go down over enemy teritory... An instrucor in the 70's made sure we were paranoid about both the berylium oxide and explosives... ___ 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] beryllium oxide
James Webb space telescope and Utah Beryllium mine http://heliophysics.org/headlines/y2008/10dec_mirror.htm On Fri, Jan 16, 2009 at 3:20 PM, Tom Clifton kc0...@yahoo.com wrote: Also used on old lighthouse tubes used for uhf and low microwave applications fro the '40's and '50's. If my memory serves me, these tubes were found in devices like the airborne APX-6 IFF Transponder in which the greatest hazard was the detonators used to destroy the device should a plane go down over enemy teritory... An instrucor in the 70's made sure we were paranoid about both the berylium oxide and explosives... ___ 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] beryllium oxide
I was once told that the white sticky paste put under power transistors years ago as a heat conduction aid was dangerous because it was based on berylium oxide cheers, Neville Michie ___ 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] beryllium oxide
Hi Bruce: Thanks for the MDA Technology link. I didn't know that Beryllium was used to make mirrors and their metering structures for space apps. It sure sounds like the best material for that use. I'd bet that's how spy sat mirrors are made. Have Fun, Brooke Clarke http://www.prc68.com Bruce Griffiths wrote: Bruce Griffiths wrote: Poul-Henning Kamp wrote: In message 4970e72d.1050...@rubidium.dyndns.org, Magnus Danielson writes: I have encountered Beryllium in a field none of you mentioned, as material for speaker cones. Light and very rigid. Perfect for the top driver for horns. I recall something about high speed of sound. It is also used for mirrors for certain, usually classified, applications. One unclassified application is the 1.12m diameter secondary mirrors of ESO's 4 VLT telescopes in Chile. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. For additional applications in some classified and unclassified programs: http://www.mdatechnology.net/techprofile.aspx?id=175 An application for breyllium mirrors at CERN: http://cdsweb.cern.ch/record/944244?ln=no Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts 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] beryllium oxide
In message 49710157.5030...@pacific.net, Brooke Clarke writes: I'd bet that's how spy sat mirrors are made. Your Tax Money At Work Quiz: 1. Why do you think there was so little research involved in the mirror construction for the Webb Telescope ? 2. Why do you think the KeyHole satellites where so friggin expensive ? 3. Connect the dots. :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | 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 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] beryllium oxide
Guys, isn't this whole thread getting a bit off-topic. 2009/1/17 Poul-Henning Kamp p...@phk.freebsd.dk: In message 49710157.5030...@pacific.net, Brooke Clarke writes: I'd bet that's how spy sat mirrors are made. Your Tax Money At Work Quiz: 1. Why do you think there was so little research involved in the mirror construction for the Webb Telescope ? 2. Why do you think the KeyHole satellites where so friggin expensive ? 3. Connect the dots. :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | 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 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Steve Rooke - ZL3TUV G8KVD JAKDTTNW Omnium finis imminet ___ 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] beryllium oxide
On 1/16/09 12:34 PM, M. Warner Losh i...@bsdimp.com wrote: But what about the Beryllium Sphere? What happens when you activate that? Warner The sphere merely provides the power for the Omega 13. That's what gets activated. And now that you mention such things, the Omega 13 has effects that would surely interest a time-nut. For all we know tvb has one (or three) stashed in his secret lair. ___ 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] beryllium oxide
Also in the Heath SB-230. I wish I still had mine. 73, Dick, W1KSZ -Original Message- From: WB6BNQ wb6...@cox.net Sent: Jan 16, 2009 1:52 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] beryllium oxide Another place to find it is in old Motorola two-way radio high power VHF amplifiers. These amplifiers used a solid metal anode and the the tubes were clamped up against a beryllium block (white square about 3/4 inch) that was attached to a heat sink. BillWB6BNQ ___ 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] beryllium oxide
Re: Beryllium was originally called glucinium becuase it and its salts tasted very sweet. In fact, tasting used to be a diagnostic test for the presence of beryllium. I remember from my inorganic chem course that lead acetate was also called sugar of lead because of it's sweet taste. and if tasting lead salts doesn't send a shiver up your spine... http://en.wikipedia.org/wiki/Lead(II)_acetate On Fri, Jan 16, 2009 at 2:15 PM, Steve Rooke sar10...@gmail.com wrote: Guys, isn't this whole thread getting a bit off-topic. Yes, it is getting off topic. Delightfully so. 2009/1/17 Poul-Henning Kamp p...@phk.freebsd.dk: In message 49710157.5030...@pacific.net, Brooke Clarke writes: I'd bet that's how spy sat mirrors are made. Your Tax Money At Work Quiz: 1. Why do you think there was so little research involved in the mirror construction for the Webb Telescope ? 2. Why do you think the KeyHole satellites where so friggin expensive ? 3. Connect the dots. :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | 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 To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Steve Rooke - ZL3TUV G8KVD JAKDTTNW Omnium finis imminet ___ 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. -- --Eric _ Eric Garner ___ 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.
