TT:
There was an interesting (to me) article in the August 1998 issue of
IEEE Spectrum magazine about the continued use of vacuum tubes in high-end
audio equipment and musical instrument amplifiers. The article's main
thesis is that tubes provide "better-sounding" audio at high levels than
could (or still can) be achieved by solid-state audio processing circuitry.
Apparently there are still some applications besides QRO microwaves for
which such hollow-state devices are better suited.
73 de
Gene Smar AD3F
----- Original Message -----
From: "Jim Miller" <JimMiller@STL-Online.Net>
To: <towertalk@contesting.com>
Sent: Tuesday, November 16, 2004 4:16 PM
Subject: Re: [TowerTalk] Vacuum tube 100 years old today
> I was in missile class in the Air Force in 1963 and the lab and course was
> entirely in tubes even though the missile was entirely in transistors.
The
> adaptation was very short (minutes, maybe and hour) and said that
> transistors worked like tubes except at lower voltages and power levels.
> That was all there was to transistors !!! Not bad really for a class that
> hadn't been rewritten yet (and that may have been all the instructor knew
at
> that time).
>
> 73, de Jim KG0KP
>
> ----- Original Message -----
> From: "Bob Nielsen" <nielsen@oz.net>
> To: <towertalk@contesting.com>
> Sent: Tuesday, November 16, 2004 12:10 PM
> Subject: Re: [TowerTalk] Vacuum tube 100 years old today
>
>
> > On Tue, Nov 16, 2004 at 11:28:11AM -0500, Tom Rauch wrote:
> > > On Nov. 16, 1904 Fleming patented the Fleming valve. The
> > > vacuum tube is 100 years old today (exactly 46 years to the
> > > day older than I am).
> > >
> > > I was an electrical engineering student in the late 60's.
> > > The electronics lab stock room was full of tubes and
> > > sockets, and our benches had 300 volt power supplies. About
> > > 50% of our inventory and study was tube related. I built a
> > > complete 500 watt HF station, receiver and transmitter, from
> > > stock room parts in my spare time. Every component necessary
> > > was in the stock room. From a textbook I still use,
> > > "Electronic Amplifier Circuits" McGraw-Hill Electrical
> > > Engineering Series 1961, comes the following quote:
> > >
> > > "For many applications a relative newcomer, the transistor,
> > > is replacing vacuum tube types because of the greater
> > > inherent reliability, lower power consumption, and smaller
> > > size. However, the complete replacement of the tube by the
> > > transistor does not seem likely, for the latter has
> > > shortcomings at high temperatures and high radiation
> > > intensities and in the production of high power at high
> > > frequencies. "
> > >
> > > About ten years later I received a call asking if I wanted
> > > any of those old tubes, tube related books, or HV bench
> > > power supplies before they hit the dumpster.
> > >
> >
> > I was taking a senior physics class in electronics at UCLA in 1962 and
> > we spent some time studying vacuum tube circuits. The professor was
> > asked if we were going to learn anything about transistors and replied
> > that he had never studied them himself, since he felt that they were a
> > fad which wouldn't last.
> >
> > 73,
> > Bob N7XY
> > _______________________________________________
> >
> > See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
any
> questions and ask for Sherman, W2FLA.
> >
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> >
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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