[NLRS] Fwd: Re: [scarc] "I shall return ..."

[S. Earl Jarosh]

Jerry,

When is a tube not a tube?  Effectively they have developed a vacuumless
tube technology eliminating the need for a substrate at the nanometer level
and therefore eliminating the velocity aspect of semiconductors.  While only
in proof of concept stage it could provide a whole new scenario in speed and
jitter issues in technology.  It will be interesting to see where this can
go.


S. Earl Jarosh, N0HZ
Cell:  612.868.1313
Off:   763.545.3275
Home:  763.546.7897
Fax:   763.546.7897
earl at moneycenters.com

 
-----Original Message-----
From: nlrs-bounces at mailman.qth.net [mailto:nlrs-bounces at mailman.qth.net] On
Behalf Of Dr. Gerald N. Johnson
Sent: Friday, May 25, 2012 10:53 PM
To: NLRS Reflector
Subject: [NLRS] Fwd: Re: [scarc] "I shall return ..."





-------- Original Message --------
Subject: Re: [scarc] "I shall return ..."
Date: Fri, 25 May 2012 16:58:20 -0500
From: Dr. Gerald N. Johnson <geraldj at weather.net>
Reply-To: geraldj at weather.net
To: scarc at iastate.edu

Tubes have not left very high power transmitters yet.

As for receiving and computing, there is more computer power today in a
volume the size of a 6SN7GT than there was in a bushel sized computer a
decade ago, and more computer power in the volume of that tube than all the
world's computers two decades ago all together. Today the package is
increasingly important to make the hardware big enough for human fingers to
handle while the contents gets to have a 2 GHz CPU with 100 GB of memory in
two chip scale packages maybe as big as 1/2" square by 1/16th inch thick but
probably smaller this week.

Part of the problems with EMP and cosmic particles in solid state is that
the geometry of the parts is the size of those atomic particles (with new
semiconductor using 12 micron geometry next year) so that the passage of
that atomic particle changes stored energy (as most memory is based on
stored charges) with very low voltage supplies like 1.2 volts to keep power
consumption down because the capacitive gates take more drive power with
larger voltage swings to charge in a few picoseconds.

The only way tubes could be competitive would be if the tube geometry was as
small working at similar low voltages, and then it would be as susceptible
to EMP and cosmic particles as semiconductors.

As for electron mobility, there are commercial MMICs made for the 1/2 to
1 TeraHz region and there never have been tubes made for that frequency
range. Gallium Arsenide has pretty good electron mobility and when the
active device is only 20 microns across, it doesn't take long for that
electron to make the passage.

73, Jerry, K0CQ

On 5/25/2012 1:55 PM, W0WOI at aol.com wrote:
> *Return of the Vacuum Tube *
>
> Vacuum tubes suffered a slow death during the 1950s and '60s thanks to 
> the invention of the transistor.specifically, the ability to 
> mass-produce transistors by chemically engraving, or etching, pieces 
> of silicon. Transistors were smaller, cheaper, and longer lasting. 
> They could also be packed into microchips to switch on and off 
> according to different, complex inputs, paving the way for smaller, 
> more powerful computers.
> But transistors weren't better in all respects. Electrons move more 
> slowly in a solid than in a vacuum, which means transistors are 
> generally slower than vacuum tubes; as a result, computing isn't as 
> quick as it could be. What's more, semiconductors are susceptible to 
> strong radiation, which can disrupt the atomic structure of the 
> silicon such that the charges no longer move properly. That's a big 
> problem for the military and NASA, which need their technology to work 
> in radiation-harsh environments such as outer space.
> http://news.sciencemag.org/sciencenow/2012/05/return-of-the-vacuum-tub
> e.html
>
>
>
>
> _______________________________________________
> Story County Amateur Radio Club email list scarc mailing list 
> scarc at iastate.edu https://mailman.iastate.edu/mailman/listinfo/scarc
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