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Building a new shortwave tube radio
On Nov 12, 2:44*pm, John Smith wrote:
On 11/11/2011 10:10 PM, RHF wrote: ... -wrt- Faraday Cage : Old Metal {Steel} Garbage Can with a tight fitting Lid. *-store-holding- + The Solid State AM/FM/SW Radio + Plenty of Batteries -or- Re-Chargeable Batteries and a Solar Charger -no-tubes-required- ~ RHF * . Satellites are withstanding these on an almost daily basis, for years, if not decades ... doesn't seem to be a real problem anymore ... however, laying hands to that technology might be a bit of a different story ... as, while one nation might wants its' own satellites hardened, it certainly doesn't want the enemies ... Regards, JS As far as I know- none of the satellites are using vacuum tubes . That's the reality . |
Building a new shortwave tube radio
wrote in message ... As far as I know- none of the satellites are using vacuum tubes . That's the reality . -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- All satellites still use these for output: http://en.wikipedia.org/wiki/Traveling-wave_tube |
Building a new shortwave tube radio
On Nov 12, 8:55*pm, "Brenda Ann"
wrote: wrote in ... As far as I know- none of the satellites are using vacuum tubes . That's the reality . ---------------------------------------------------------------------------*----- ---------------------------------------------------------------------------*----- All satellites still use these for output: http://en.wikipedia.org/wiki/Traveling-wave_tube Oh,sorry. But this may be a miniature tube for microwave frequencies . Where do they obtain high voltages - it must be smps type . Solar panels?? |
Building a new shortwave tube radio
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Building a new shortwave tube radio
On 11/12/2011 5:55 PM, Brenda Ann wrote:
wrote in message ... As far as I know- none of the satellites are using vacuum tubes . That's the reality . -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- All satellites still use these for output: http://en.wikipedia.org/wiki/Traveling-wave_tube Fact of the matter is, you don't need tubes in space, you already have a much better vacuum than can ever be created on earth ... you simply need the elements ... Regards, JS |
Building a new shortwave tube radio
On 11/12/2011 11:12 PM, Don Pearce wrote:
On Sat, 12 Nov 2011 17:24:02 -0800 (PST), wrote: On Nov 12, 2:44 pm, John wrote: On 11/11/2011 10:10 PM, RHF wrote: ... -wrt- Faraday Cage : Old Metal {Steel} Garbage Can with a tight fitting Lid. -store-holding- + The Solid State AM/FM/SW Radio + Plenty of Batteries -or- Re-Chargeable Batteries and a Solar Charger -no-tubes-required- ~ RHF . Satellites are withstanding these on an almost daily basis, for years, if not decades ... doesn't seem to be a real problem anymore ... however, laying hands to that technology might be a bit of a different story ... as, while one nation might wants its' own satellites hardened, it certainly doesn't want the enemies ... Regards, JS As far as I know- none of the satellites are using vacuum tubes . That's the reality . Dream on. Just about every satellite in the sky uses vacuum tubes. The TWT (travelling wave tube) is still the way to generate high, reliable power for space-borne transmitters. d They would be fools to attempt to boost the weight and fragility of vacuum tubes into space, if they have any other alternative ... high power is easily handled with the modern transistors ... the energy requirements of the heaters is also another no-go ... Regards, JS |
Building a new shortwave tube radio
On Sat, 12 Nov 2011 23:42:22 -0800, John Smith
wrote: On 11/12/2011 11:12 PM, Don Pearce wrote: On Sat, 12 Nov 2011 17:24:02 -0800 (PST), wrote: On Nov 12, 2:44 pm, John wrote: On 11/11/2011 10:10 PM, RHF wrote: ... -wrt- Faraday Cage : Old Metal {Steel} Garbage Can with a tight fitting Lid. -store-holding- + The Solid State AM/FM/SW Radio + Plenty of Batteries -or- Re-Chargeable Batteries and a Solar Charger -no-tubes-required- ~ RHF . Satellites are withstanding these on an almost daily basis, for years, if not decades ... doesn't seem to be a real problem anymore ... however, laying hands to that technology might be a bit of a different story ... as, while one nation might wants its' own satellites hardened, it certainly doesn't want the enemies ... Regards, JS As far as I know- none of the satellites are using vacuum tubes . That's the reality . Dream on. Just about every satellite in the sky uses vacuum tubes. The TWT (travelling wave tube) is still the way to generate high, reliable power for space-borne transmitters. d They would be fools to attempt to boost the weight and fragility of vacuum tubes into space, if they have any other alternative ... high power is easily handled with the modern transistors ... the energy requirements of the heaters is also another no-go ... Regards, JS Energy requirements are not a problem, and neither is G-loading on takeoff. You are inventing problems where none need exist. TWTs are mega-reliable devices with a very predictable life curve. It is much more important to know exactly how long and how well your satellite is going to work than to hope to get longer by using a technology that might last longer, but will more probably die unexpectedly when struck by a cosmic ray burst. d |
Building a new shortwave tube radio
It is much more important to know exactly how long and how well your satellite is going to work than to hope to get longer by using a technology that might last longer, but will more probably die unexpectedly when struck by a cosmic ray burst. Sometimes you can not predict how long a satellite will be used. A friend of mine worked on a civilian satellite for a defense contractor and just before the division was sold off, cleaned out any old documents and files they had on it. Since the satellite he had worked on was way past its expected life (but still in use), the contracts had long expired, the work was not classified and a new improved one was due to be launched in a few days, he was told to dump it all. A few days later, the booster exploded on the pad, and the replacement was destroyed. The sattelite was kept running for many years, although there were no documents on what to do or how it was built. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM My high blood pressure medicine reduces my midichlorian count. :-( |
Building a new shortwave tube radio
On Sat, 12 Nov 2011 17:24:02 -0800, arthrnyork wrote:
As far as I know- none of the satellites are using vacuum tubes . That's the reality . Almost all of them use TWTAs, a form of vacuum tube, for their final downlink amplifiers. |
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