Hollow State devices (tubes) have a number of potential advantages over Solid
State Devices.
- Orders of magnitude greater electron mobility (they fly through vacuum
better than through solids)
- Mechanical construction around the perimeter rather than through the body
of the active area
- minimal need for packaging when used in space
Areas of advanced technology include...
Spindt cathodes
- http://en.wikipedia.org/wiki/Field_emitter_array
- Make a sharp point on the atomic scale and electronics emit without
heating
Plasma TV's
- Highly integrated Hollow State device
Relativistic Electron Tubes
- http://en.wikipedia.org/wiki/Gyrotron
- http://en.wikipedia.org/wiki/Free_electron_laser
- basically a free electron Maser
Lastly
- http://www.4p8.com/eric.brasseur/intvac.html
jeff, wa1hco
On 08/13/2011 02:58 PM, Jim Barber wrote:
> I made a side-thread for this since it isn't directly related:
>
> This discussion of "super semis" makes me wonder if anyone is still
> engaged in vacuum tube research these days. Could any of the basic tube
> wear points be improved on with modern technology? Could filaments be
> made to emit twice as long without degradation?
>
> I just looked at the CPI Eimac site and I can't see where they're
> motivated or have the resources to innovate at the basic level. They
> list "Amateur Service" as a product category, which can't bode well for
> volume sales... Assuming MOSFET technology passes tubes by at high power
> levels, will they just go quietly into the night?
>
> I hope not - there's no second chances with current solid state devices.
> Generally speaking, they do not degrade gracefully... ;-)
>
> 73,
> Jim, N7CXI
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|