[Big Bad Bob]

https://www.sciencemag.org/news/2012...rn-vacuum-tube

quote
The new device is a cross between today's transistors and the vacuum
tubes of yesteryear. It's small and easily manufactured, but also fast
and radiation-proof. Meyyappan, who co-developed the "nano vacuum tube,"
says it is created by etching a tiny cavity in phosphorous-doped
silicon. The cavity is bordered by three electrodes: a source, a gate,
and a drain. The source and drain are separated by just 150 nanometers,
while the gate sits on top. Electrons are emitted from the source thanks
to a voltage applied across it and the drain, while the gate controls
the electron flow across the cavity. In their paper published online
today in Applied Physics Letters, Meyyappan and colleagues estimate that
their nano vacuum tube operates at frequencies up to 0.46 terahertz€”some
10 times faster than the best silicon transistors.
/quote

cool stuff. Seems to work without a heated cathode. not sure if voltage
"across the source and the drain" is in any way responsible for
thermionic emission or some other mechanism...


--
(aka 'Bombastic Bob' in case you wondered)

'Feeling with my fingers, and thinking with my brain' - me

'your story is so touching, but it sounds just like a lie'
"Straighten up and fly right"

[[email protected]]

Big Bad Boob wrote:
---------------------------------
https://www.sciencemag.org/news/2012...rn-vacuum-tube

cool stuff. Seems to work without a heated cathode. not sure if voltage
"across the source and the drain" is in any way responsible for
thermionic emission or some other mechanism...


** Lemme see - there is no vacuum, no tube, no thermionic emission and
electrons travel across a tiny air space. Right ?

" VaccumTube" my arse.

The author must be a u-tuber - deliberately *misnaming* to get clicks.

...... Phil

[Lord Valve[_3_]]

On Tuesday, February 9, 2021 at 4:32:37 PM UTC-7, wrote:
Big Bad Boob wrote:
---------------------------------
https://www.sciencemag.org/news/2012...rn-vacuum-tube

cool stuff. Seems to work without a heated cathode. not sure if voltage
"across the source and the drain" is in any way responsible for
thermionic emission or some other mechanism...

** Lemme see - there is no vacuum, no tube, no thermionic emission and
electrons travel across a tiny air space. Right ?

" VaccumTube" my arse.

The author must be a u-tuber - deliberately *misnaming* to get clicks.

..... Phil

It actually *is* a vacuum tube, but it's pretty flaky. There are a bunch
of effects pedals out now (and an amp or two) which use it. Here's
a couple of URLs on it, one from the manufacturer:

https://korgnutube.com/en/

https://diyaudiostore.com/products/korg-nutube

The second one has some numbers and graphs and stuff.
If you want to mess with one, they'll be glad to sell it to you
for only fifty bucks US. (OUCH!)

Lastly, you should watch this - this guy is so absolutely clueless
you'll be ROFL by the time you get to the end. His comment about
the exhaust port is especially hilarious:

https://www.youtube.com/watch?v=6Azl1vzoLpA

He probably posts to alt.guitar.amps. ;-)

Lord Valve

[[email protected]]

Lord Valve wrote:
==================
wrote:

It actually *is* a vacuum tube, but it's pretty flaky.

** Fraid you are barking up the wrong tree.

The "science mag"' article is about a totally different development.
================================================

Lastly, you should watch this - this guy is so absolutely clueless
you'll be ROFL by the time you get to the end. His comment about
the exhaust port is especially hilarious:

https://www.youtube.com/watch?v=6Azl1vzoLpA

He probably posts to alt.guitar.amps. ;-)


** The " guitologist " is a hoot.

Reminds me of the Middle Ages when barbers carried out surgery on people cos they owned the sharpest knives.


...... Phil

[Lord Valve[_3_]]

On Tuesday, February 9, 2021 at 7:22:19 PM UTC-7, wrote:
Lord Valve wrote:
==================
wrote:

It actually *is* a vacuum tube, but it's pretty flaky.
** Fraid you are barking up the wrong tree.

The "science mag"' article is about a totally different development.
================================================

I shoulda took a closer look - sorry.


Lastly, you should watch this - this guy is so absolutely clueless
you'll be ROFL by the time you get to the end. His comment about
the exhaust port is especially hilarious:

https://www.youtube.com/watch?v=6Azl1vzoLpA

He probably posts to alt.guitar.amps. ;-)

** The " guitologist " is a hoot.

Reminds me of the Middle Ages when barbers carried out surgery on people cos they owned the sharpest knives.


..... Phil

The authorities in Oz give you a covid shot yet? I'm on
the list - supposed to be priority, I'm 73 - but I ain't seen
jack **** so far.

LV

[[email protected]]

Lord Valve wrote:
================

** The " guitologist " is a hoot.

Reminds me of the Middle Ages when barbers carried out surgery on people cos they owned the sharpest knives.

The authorities in Oz give you a covid shot yet? I'm on
the list - supposed to be priority, I'm 73 - but I ain't seen
jack **** so far.


** Later this year maybe, priority folk like emergency service workers will get first go in March.

The risk here in NSW is very low.


...... Phil

[Big Bad Bob]

On 2021-02-09 16:41, Lord Valve wrote:
It actually *is* a vacuum tube, but it's pretty flaky. There are a bunch
of effects pedals out now (and an amp or two) which use it. Here's
a couple of URLs on it, one from the manufacturer:

https://korgnutube.com/en/

they would e-mail the data sheet to me but I have to give them sales
contact info first. Naaah. I'll wait until digikey has them.

https://diyaudiostore.com/products/korg-nutube

The second one has some numbers and graphs and stuff.
If you want to mess with one, they'll be glad to sell it to you
for only fifty bucks US. (OUCH!)

if I wanted to build an amp to test a design it's probably worth it.

Looking at the curves, it runs with a positive grid voltage in most of
the examples. that's not entirely ideal [obviously] especially when
plate current is measuree in microamps.

apparently the ref circuit solves that by using a JFET front-end as a
voltage follower.

Still interesting, but I can't see any advantages of this over using a
MOSFET other than to say "it is a tube". HOWEVER... I would definitely
expect the technology to improve and at some point use an indirectly
heated cathode.

Having a mu factor of 14 isn't all that exciting either. I'd expect 50
or 60 to be of real use (like a 12AT7) in a preamp, or 100 like a 12AX7.

still - the low volts, low heater power, and small physical size
definitely have an appeal.