7556	2012-07-02 11:28:19	Ashhar Farhan	nano vacum tubes?
Message	Date	From	Subject
as this group is interested in new experiments in radio devices and circuits, i thought this might be relevant ... http://news.sciencemag.org/sciencenow/2012/05/return-of-the-vacuum-tube.html - farhan
7557	2012-07-02 12:06:27	William Carver	Re: nano vacum tubes?
Interesting! With a little development maybe the pentagrid mixer will make a comeback? W7AAZ On Mon, 2012-07-02 at 23:58 +0530, Ashhar Farhan wrote: > > as this group is interested in new experiments in radio devices and > circuits, i thought this might be relevant ... > http://news.sciencemag.org/sciencenow/2012/05/return-of-the-vacuum-tube.html > > - farhan
7558	2012-07-02 12:11:55	Johan H. Bodin	Re: nano vacum tubes?
William Carver wrote: > Interesting! With a little development maybe the pentagrid mixer will > make a comeback? Yes, and with a little further development we may see the reincarnation of the magic eye in an SMD package! :-) http://www.magiceyetubes.com/ 73 Johan SM6LKM
7559	2012-07-02 12:11:56	Gary, WB9JPS	Re: nano vacum tubes?
Interesting indeed! Field emissi
7561	2012-07-02 20:17:01	KK7B	Re: nano vacum tubes?
Thanks Farhan--interesting. One small item the article got wrong is the speed of transistors. The article states that the nano vacuum triode operates at "0.46 THz, about ten times faster than the best transistors." The best transistors are also about that fast. Recent work at JPL has pushed practical multi-stage transistor amplifiers up to 325 GHz or so, with others reporting gain to around 725 GHz. Even garden variety silicon processes for mass producti
7562	2012-07-02 21:09:06	William Carver	Re: nano vacum tubes?
In the late 1950s I remember reading an article in CQ that made a lot of sense to me. It started by saying its important to understand what's NOT possible rather than beat your head against the wall. It then described how current flow in a transistor being like pinball machine. Balls roll downhill, but hit posts (in the crystal lattice) and bouncing around slowing its motion. It concluded by saying transistors were great in audio and power supplies, but we should never expect this kind of device to ever be good at more than several hundred KHz. W7AAZ On Tue, 2012-07-03 at 03:17 +0000, KK7B wrote: > > Thanks Farhan--interesting. One small item the article got wrong is > the speed of transistors. The article states that the nano vacuum > triode operates at "0.46 THz, about ten times faster than the best > transistors." The best transistors are also about that fast. Recent > work at JPL has pushed practical multi-stage transistor amplifiers up > to 325 GHz or so, with others reporting gain to around 725 GHz. Even > garden variety silicon processes for mass producti
7563	2012-07-08 01:11:22	ha5rxz	Re: nano vacum tubes?
Well, perhaps not nano vacuum tubes but I came across an interesting find this Thursday. A fellow ham brought his component collecti
7564	2012-07-08 02:26:38	Neil Douglas	Re: nano vacum tubes?
Peter, These sound like Nuvistors - from the early 1960's, I built a 2 metre convertor using 6CW4's. Nuvistors were made by RCA and Mullard / Phillips. I worked on some TV cameras that used them as the first stage of the video amplifier to get a very high input impedance. The Russians also used them in their aircraft radios in the cold war era - they were much more tolerant to radiation than the semiconductors of the time. Regards NeilD G4SHJ _____
7565	2012-07-08 06:24:16	Paul Anderson	Re: nano vacum tubes?
I have something kind of similar, but made of glass. I believe they were called acorn tubes. Sent from my iPhone On 2012-07-08, at 5:26 AM, "Neil Douglas" <neil.douglas@tesco.net> wrote: > Peter, > > > > These sound like Nuvistors - from the early 1960's, I built a 2 metre > convertor using 6CW4's. > > > > Nuvistors were made by RCA and Mullard / Phillips. I worked on some TV > cameras that used them > > as the first stage of the video amplifier to get a very high input > impedance. > > > > The Russians also used them in their aircraft radios in the cold war era - > they were much more tolerant > > to radiation than the semiconductors of the time. > > > > Regards > > > > NeilD > > G4SHJ > > > > > > > > > > > > _____ > >
7566	2012-07-08 12:51:12	Dean Blake	Re: nano vacum tubes?
Russians had tubes in some of their vietnam era aircrafts too.. why? Because their semiconductor abilities left alot to be desired... Bulky, heavy, and un-reliable equipment using tubes gave us an advantage over them and had nothing to do with radiation effecting semiconductors as it would in outer space... I lived that era and many of their electronic systems the communist countries had were way behind what we had... but then they were communist... free enterprise and capital were something they didn't have, another reason to be proud of our great country where you're free to invent, patent, sell and compete. K4DSB Dean To: emrfd@yahoogroups.com From: neil.douglas@tesco.net Date: Sun, 8 Jul 2012 10:26:35 +0100 Subject: RE: [emrfd] Re: nano vacum tubes? Peter, These sound like Nuvistors - from the early 1960's, I built a 2 metre convertor using 6CW4's. Nuvistors were made by RCA and Mullard / Phillips. I worked on some TV cameras that used them as the first stage of the video amplifier to get a very high input impedance. The Russians also used them in their aircraft radios in the cold war era - they were much more tolerant to radiation than the semiconductors of the time. Regards NeilD G4SHJ _____
7567	2012-07-08 17:22:06	Paul Anderson	Re: nano vacum tubes?
Things certainly weren't helped by the Stalinist purges. One of my other hobbies is collecting slide rules. There is a glut of Russian slide rules on eBay, I guess they were using them well into the '80s. Sent from my iPad On 2012-07-08, at 3:49 PM, Dean Blake <dsblake1@msn.com> wrote: > > Russians had tubes in some of their vietnam era aircrafts too.. why? Because their semiconductor > abilities left alot to be desired... Bulky, heavy, and un-reliable equipment using tubes gave us an advantage > over them and had nothing to do with radiation effecting semiconductors as it would in outer space... > > I lived that era and many of their electronic systems the communist countries had were way behind what we had... > but then they were communist... free enterprise and capital were something they didn't have, another reason to > be proud of our great country where you're free to invent, patent, sell and compete. > > > K4DSB > Dean > > > > > To: emrfd@yahoogroups.com > From: neil.douglas@tesco.net > Date: Sun, 8 Jul 2012 10:26:35 +0100 > Subject: RE: [emrfd] Re: nano vacum tubes? > > > > > > Peter, > > These sound like Nuvistors - from the early 1960's, I built a 2 metre > convertor using 6CW4's. > > Nuvistors were made by RCA and Mullard / Phillips. I worked on some TV > cameras that used them > > as the first stage of the video amplifier to get a very high input > impedance. > > The Russians also used them in their aircraft radios in the cold war era - > they were much more tolerant > > to radiation than the semiconductors of the time. > > Regards > > NeilD > > G4SHJ > > _____ > >
7568	2012-07-08 18:15:04	davidpnewkirk	Re: nano vacum tubes?
I like how experimenters are playing with vacuum fluorescent displays as amplifiers (and probably as oscillators); example: http://www.hpfriedrichs.com/rr-vfd.htm Fun to build an oscillator based on a xE5, xU5 or 1629 Magic-Eye tube; it self-indicates its relative activity. Best regards, Dave amateur radio W9VES doing the unnecessary with the obsolete
7569	2012-07-08 18:21:59	Hector Pascal	Re: nano vacum tubes?
Russians had tubes in some of their vietnam era aircrafts too.. why? Because their semiconductor abilities left a lot to be desired...>> Possibly they were cleverer than you think, since nuvistor style tubes were designed to be inherently more EMP proof in a nuclear war scenario.