Simple audio amp design...

[Lasse Langwadt Christensen]

mandag den 27. december 2021 kl. 01.22.07 UTC+1 skrev Cursitor Doom:

On Sun, 26 Dec 2021 06:27:17 -0800 (PST), Lasse Langwadt Christensen
lang...@fonz.dk> wrote:

lørdag den 25. december 2021 kl. 15.17.33 UTC+1 skrev jla...@highlandsniptechnology.com:
On Sat, 25 Dec 2021 00:29:44 -0800 (PST), Wim Ton <wim...@gmail.com
wrote:
On Friday, 24 December 2021 at 15:18:14 UTC+1, jla...@highlandsniptechnology.com wrote:
On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

On 23/12/21 19:03, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.

Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.

The vacuum would be the interesting part of that.
Most tubes used a mechanical vacuum pump and then a getter to clean
up. Big beautiful transmitting tubes and PMTs and other high-quality
tubes mostly weren\'t gettered, probably baked and pumped hard.

I have a couple of Boy Electrician books with similar things.
They also have sections on fun things you can do with your
X-ray machine. They do presume you buy the tube, though, and
warn you to stop if your skin starts becoming red.
I had The Boy Scientist when I was a kid. Tons of dangerous stuff. I
wonder if I can find a copy somewhere.

I also have a book on how to make soap, and a Scientific
American Cyclopedia (sic) of Formulas (sic). Everything
from beverages to insecticides and a couple of dozen types
of solder.

I\'m well set pour \"après le déluge\".


My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.

I\'m really into that kind of thing. In theory at any rate.

Unfortunately life is too short to /do/ everything. We are
lucky we have options.
Yeah. I would have made a terrible peasant farmer.




--

I yam what I yam - Popeye
To see what it takes to really make things from scratch see: \"The toaster project\".
Most \"make things from scratch\" ideas require for example blast furnaces with their supply chain to provide high quality steel, etc.
Even HD Thoreau uses a second-hand building for his Walden project.
Wim
The idea of a settlement surving on Mars is absurd. There are no
WalMarts, no Home Depots, no pizza joints, no trees for firewood.
Nothing to eat or breathe.

Our civilization grew very slowly at first. You need a lathe to make a
lathe.

https://youtu.be/XCt3LooUVsQ
You need a lathe to make a lathe, but that\'s not *all* you need. The
guy in the video uses wood to get around this problem, but if you wish
to make a serious metal turning lathe, you will need some means of
producing castings for the turned components such as shafts and
bearings to be stably held. And for screw cutting, you then need some
way of making gears as well. You can\'t make a practical
metal-turning/screw-cutting lathe without castings, a mill and various
cutting bits additionally. And the cutters require a grinder to put an
edge on \'em. It\'s therefore not as simple as Bill Sloman
suggested^h^h^h^h^h^h^h^h^h^h.
;-

once you build a bad lathe by hand you use that to make a better lathe ..
earliest know castings is more than 5000 years old
you can make gears with a file, https://youtu.be/Mo7jCA27xKo

https://youtu.be/LBuUOO3qn30

 

[Phil Hobbs]

jlarkin@highlandsniptechnology.com wrote:

On Mon, 27 Dec 2021 00:22:00 +0000, Cursitor Doom <cd@nospam.com
wrote:

On Sun, 26 Dec 2021 06:27:17 -0800 (PST), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

lørdag den 25. december 2021 kl. 15.17.33 UTC+1 skrev jla...@highlandsniptechnology.com:
On Sat, 25 Dec 2021 00:29:44 -0800 (PST), Wim Ton <wim...@gmail.com
wrote:
On Friday, 24 December 2021 at 15:18:14 UTC+1, jla...@highlandsniptechnology.com wrote:
On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

On 23/12/21 19:03, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.

Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.

The vacuum would be the interesting part of that.
Most tubes used a mechanical vacuum pump and then a getter to clean
up. Big beautiful transmitting tubes and PMTs and other high-quality
tubes mostly weren\'t gettered, probably baked and pumped hard.

I have a couple of Boy Electrician books with similar things.
They also have sections on fun things you can do with your
X-ray machine. They do presume you buy the tube, though, and
warn you to stop if your skin starts becoming red.
I had The Boy Scientist when I was a kid. Tons of dangerous stuff. I
wonder if I can find a copy somewhere.

I also have a book on how to make soap, and a Scientific
American Cyclopedia (sic) of Formulas (sic). Everything
from beverages to insecticides and a couple of dozen types
of solder.

I\'m well set pour \"après le déluge\".


My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.

I\'m really into that kind of thing. In theory at any rate.

Unfortunately life is too short to /do/ everything. We are
lucky we have options.
Yeah. I would have made a terrible peasant farmer.




--

I yam what I yam - Popeye
To see what it takes to really make things from scratch see: \"The toaster project\".
Most \"make things from scratch\" ideas require for example blast furnaces with their supply chain to provide high quality steel, etc.
Even HD Thoreau uses a second-hand building for his Walden project.
Wim
The idea of a settlement surving on Mars is absurd. There are no
WalMarts, no Home Depots, no pizza joints, no trees for firewood.
Nothing to eat or breathe.

Our civilization grew very slowly at first. You need a lathe to make a
lathe.

https://youtu.be/XCt3LooUVsQ

You need a lathe to make a lathe, but that\'s not *all* you need. The
guy in the video uses wood to get around this problem, but if you wish
to make a serious metal turning lathe, you will need some means of
producing castings for the turned components such as shafts and
bearings to be stably held. And for screw cutting, you then need some
way of making gears as well. You can\'t make a practical
metal-turning/screw-cutting lathe without castings, a mill and various
cutting bits additionally. And the cutters require a grinder to put an
edge on \'em. It\'s therefore not as simple as Bill Sloman
suggested^h^h^h^h^h^h^h^h^h^h.
;-

Not to mention the electric motor, the pulleys, the belts, and the
electric power plant out there somewhere, some of which required
lathes to build.

Mechanical averaging is a very powerful way to generate accurate motion.

With patience, you can lap three surfaces against each other pairwise to
generate almost atomically-flat surfaces. Cleaving crystals is even
better, if you have a single crystal handy.

Before interferometric control was developed around 1950, diffraction
gratings were ruled using lead screws and very long split nuts. The two
were lapped together over many cycles to smooth out the irregularities.

Once you have things that are very flat and straight, you can do a lot
via geometry.

A good read is \"Foundations of Mechanical Accuracy\" by Wayne Moore,
which is big bucks in the used market, but can be downloaded from
archive.org.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Lasse Langwadt Christensen]

mandag den 27. december 2021 kl. 21.26.39 UTC+1 skrev Phil Hobbs:

jla...@highlandsniptechnology.com wrote:
On Mon, 27 Dec 2021 00:22:00 +0000, Cursitor Doom <c...@nospam.com
wrote:

On Sun, 26 Dec 2021 06:27:17 -0800 (PST), Lasse Langwadt Christensen
lang...@fonz.dk> wrote:

lørdag den 25. december 2021 kl. 15.17.33 UTC+1 skrev jla...@highlandsniptechnology.com:
On Sat, 25 Dec 2021 00:29:44 -0800 (PST), Wim Ton <wim...@gmail.com
wrote:
On Friday, 24 December 2021 at 15:18:14 UTC+1, jla...@highlandsniptechnology.com wrote:
On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

On 23/12/21 19:03, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.

Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.

The vacuum would be the interesting part of that.
Most tubes used a mechanical vacuum pump and then a getter to clean
up. Big beautiful transmitting tubes and PMTs and other high-quality
tubes mostly weren\'t gettered, probably baked and pumped hard.

I have a couple of Boy Electrician books with similar things.
They also have sections on fun things you can do with your
X-ray machine. They do presume you buy the tube, though, and
warn you to stop if your skin starts becoming red.
I had The Boy Scientist when I was a kid. Tons of dangerous stuff. I
wonder if I can find a copy somewhere.

I also have a book on how to make soap, and a Scientific
American Cyclopedia (sic) of Formulas (sic). Everything
from beverages to insecticides and a couple of dozen types
of solder.

I\'m well set pour \"après le déluge\".


My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.

I\'m really into that kind of thing. In theory at any rate.

Unfortunately life is too short to /do/ everything. We are
lucky we have options.
Yeah. I would have made a terrible peasant farmer.




--

I yam what I yam - Popeye
To see what it takes to really make things from scratch see: \"The toaster project\".
Most \"make things from scratch\" ideas require for example blast furnaces with their supply chain to provide high quality steel, etc.
Even HD Thoreau uses a second-hand building for his Walden project.
Wim
The idea of a settlement surving on Mars is absurd. There are no
WalMarts, no Home Depots, no pizza joints, no trees for firewood.
Nothing to eat or breathe.

Our civilization grew very slowly at first. You need a lathe to make a
lathe.

https://youtu.be/XCt3LooUVsQ

You need a lathe to make a lathe, but that\'s not *all* you need. The
guy in the video uses wood to get around this problem, but if you wish
to make a serious metal turning lathe, you will need some means of
producing castings for the turned components such as shafts and
bearings to be stably held. And for screw cutting, you then need some
way of making gears as well. You can\'t make a practical
metal-turning/screw-cutting lathe without castings, a mill and various
cutting bits additionally. And the cutters require a grinder to put an
edge on \'em. It\'s therefore not as simple as Bill Sloman
suggested^h^h^h^h^h^h^h^h^h^h.
;-

Not to mention the electric motor, the pulleys, the belts, and the
electric power plant out there somewhere, some of which required
lathes to build.



Mechanical averaging is a very powerful way to generate accurate motion.

With patience, you can lap three surfaces against each other pairwise to
generate almost atomically-flat surfaces. Cleaving crystals is even
better, if you have a single crystal handy.

three plates lapped together demonstrated here: https://youtu.be/Whyw5v7L70c

 

[Lasse Langwadt Christensen]

mandag den 27. december 2021 kl. 21.43.01 UTC+1 skrev Lasse Langwadt Christensen:

mandag den 27. december 2021 kl. 21.26.39 UTC+1 skrev Phil Hobbs:
jla...@highlandsniptechnology.com wrote:
On Mon, 27 Dec 2021 00:22:00 +0000, Cursitor Doom <c...@nospam.com
wrote:

On Sun, 26 Dec 2021 06:27:17 -0800 (PST), Lasse Langwadt Christensen
lang...@fonz.dk> wrote:

lørdag den 25. december 2021 kl. 15.17.33 UTC+1 skrev jla...@highlandsniptechnology.com:
On Sat, 25 Dec 2021 00:29:44 -0800 (PST), Wim Ton <wim...@gmail.com
wrote:
On Friday, 24 December 2021 at 15:18:14 UTC+1, jla...@highlandsniptechnology.com wrote:
On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

On 23/12/21 19:03, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.

Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.

The vacuum would be the interesting part of that.
Most tubes used a mechanical vacuum pump and then a getter to clean
up. Big beautiful transmitting tubes and PMTs and other high-quality
tubes mostly weren\'t gettered, probably baked and pumped hard.

I have a couple of Boy Electrician books with similar things.
They also have sections on fun things you can do with your
X-ray machine. They do presume you buy the tube, though, and
warn you to stop if your skin starts becoming red.
I had The Boy Scientist when I was a kid. Tons of dangerous stuff. I
wonder if I can find a copy somewhere.

I also have a book on how to make soap, and a Scientific
American Cyclopedia (sic) of Formulas (sic). Everything
from beverages to insecticides and a couple of dozen types
of solder.

I\'m well set pour \"après le déluge\".


My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.

I\'m really into that kind of thing. In theory at any rate.

Unfortunately life is too short to /do/ everything. We are
lucky we have options.
Yeah. I would have made a terrible peasant farmer.




--

I yam what I yam - Popeye
To see what it takes to really make things from scratch see: \"The toaster project\".
Most \"make things from scratch\" ideas require for example blast furnaces with their supply chain to provide high quality steel, etc.
Even HD Thoreau uses a second-hand building for his Walden project.
Wim
The idea of a settlement surving on Mars is absurd. There are no
WalMarts, no Home Depots, no pizza joints, no trees for firewood.
Nothing to eat or breathe.

Our civilization grew very slowly at first. You need a lathe to make a
lathe.

https://youtu.be/XCt3LooUVsQ

You need a lathe to make a lathe, but that\'s not *all* you need. The
guy in the video uses wood to get around this problem, but if you wish
to make a serious metal turning lathe, you will need some means of
producing castings for the turned components such as shafts and
bearings to be stably held. And for screw cutting, you then need some
way of making gears as well. You can\'t make a practical
metal-turning/screw-cutting lathe without castings, a mill and various
cutting bits additionally. And the cutters require a grinder to put an
edge on \'em. It\'s therefore not as simple as Bill Sloman
suggested^h^h^h^h^h^h^h^h^h^h.
;-

Not to mention the electric motor, the pulleys, the belts, and the
electric power plant out there somewhere, some of which required
lathes to build.



Mechanical averaging is a very powerful way to generate accurate motion..

With patience, you can lap three surfaces against each other pairwise to
generate almost atomically-flat surfaces. Cleaving crystals is even
better, if you have a single crystal handy.
three plates lapped together demonstrated here: https://youtu.be/Whyw5v7L70c

The Clickspring youtube channel shows a lot of ancient layout and toolmaking techniques
in the process of making a Antikythera replica

https://youtube.com/playlist?list=PLZioPDnFPNsGnUXuZScwn6Ackf6LGILCa

 

[John Larkin]

On Mon, 27 Dec 2021 15:25:33 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

jlarkin@highlandsniptechnology.com wrote:
On Mon, 27 Dec 2021 00:22:00 +0000, Cursitor Doom <cd@nospam.com
wrote:

On Sun, 26 Dec 2021 06:27:17 -0800 (PST), Lasse Langwadt Christensen
langwadt@fonz.dk> wrote:

lørdag den 25. december 2021 kl. 15.17.33 UTC+1 skrev jla...@highlandsniptechnology.com:
On Sat, 25 Dec 2021 00:29:44 -0800 (PST), Wim Ton <wim...@gmail.com
wrote:
On Friday, 24 December 2021 at 15:18:14 UTC+1, jla...@highlandsniptechnology.com wrote:
On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

On 23/12/21 19:03, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.

Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.

The vacuum would be the interesting part of that.
Most tubes used a mechanical vacuum pump and then a getter to clean
up. Big beautiful transmitting tubes and PMTs and other high-quality
tubes mostly weren\'t gettered, probably baked and pumped hard.

I have a couple of Boy Electrician books with similar things.
They also have sections on fun things you can do with your
X-ray machine. They do presume you buy the tube, though, and
warn you to stop if your skin starts becoming red.
I had The Boy Scientist when I was a kid. Tons of dangerous stuff. I
wonder if I can find a copy somewhere.

I also have a book on how to make soap, and a Scientific
American Cyclopedia (sic) of Formulas (sic). Everything
from beverages to insecticides and a couple of dozen types
of solder.

I\'m well set pour \"après le déluge\".


My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.

I\'m really into that kind of thing. In theory at any rate.

Unfortunately life is too short to /do/ everything. We are
lucky we have options.
Yeah. I would have made a terrible peasant farmer.




--

I yam what I yam - Popeye
To see what it takes to really make things from scratch see: \"The toaster project\".
Most \"make things from scratch\" ideas require for example blast furnaces with their supply chain to provide high quality steel, etc.
Even HD Thoreau uses a second-hand building for his Walden project.
Wim
The idea of a settlement surving on Mars is absurd. There are no
WalMarts, no Home Depots, no pizza joints, no trees for firewood.
Nothing to eat or breathe.

Our civilization grew very slowly at first. You need a lathe to make a
lathe.

https://youtu.be/XCt3LooUVsQ

You need a lathe to make a lathe, but that\'s not *all* you need. The
guy in the video uses wood to get around this problem, but if you wish
to make a serious metal turning lathe, you will need some means of
producing castings for the turned components such as shafts and
bearings to be stably held. And for screw cutting, you then need some
way of making gears as well. You can\'t make a practical
metal-turning/screw-cutting lathe without castings, a mill and various
cutting bits additionally. And the cutters require a grinder to put an
edge on \'em. It\'s therefore not as simple as Bill Sloman
suggested^h^h^h^h^h^h^h^h^h^h.
;-

Not to mention the electric motor, the pulleys, the belts, and the
electric power plant out there somewhere, some of which required
lathes to build.




Mechanical averaging is a very powerful way to generate accurate motion.

With patience, you can lap three surfaces against each other pairwise to
generate almost atomically-flat surfaces. Cleaving crystals is even
better, if you have a single crystal handy.

Mica, split with an x-acto knife, is reported to have sub-nm RMS
roughness. But I guess not very flat.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Tom Gardner]

On 24/12/21 14:18, jlarkin@highlandsniptechnology.com wrote:

On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner
spamjunk@blueyonder.co.uk> wrote:

I have a couple of Boy Electrician books with similar things.
They also have sections on fun things you can do with your
X-ray machine. They do presume you buy the tube, though, and
warn you to stop if your skin starts becoming red.

I had The Boy Scientist when I was a kid. Tons of dangerous stuff. I
wonder if I can find a copy somewhere.

Yes.

It appears there are many different versions, so getting
the specific one you had as a kid might require trial and error.

 

[Cursitor Doom]

On Mon, 27 Dec 2021 05:41:27 -0800 (PST), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

once you build a bad lathe by hand you use that to make a better lathe ..
earliest know castings is more than 5000 years old
you can make gears with a file

I know. I\'ve done it myself. My big old Harrison lathe came without a
threading dial which needs to mesh with the leadscrew, so I created
one myself out of nylon using a needle file. Nylon was ideal to work
with and since this application was close to zero load, practical as
well. Dab of grease and job done. Of course any metal you can file
will work every bit as well as the machinable plastics and may well be
preferable in certain circs.

 

[Anthony William Sloman]

On Tuesday, December 28, 2021 at 12:11:03 AM UTC+11, jla...@highlandsniptechnology.com wrote:

On Mon, 27 Dec 2021 00:22:00 +0000, Cursitor Doom <c...@nospam.com> wrote:
On Sun, 26 Dec 2021 06:27:17 -0800 (PST), Lasse Langwadt Christensen
lang...@fonz.dk> wrote:
lørdag den 25. december 2021 kl. 15.17.33 UTC+1 skrev jla...@highlandsniptechnology.com:
On Sat, 25 Dec 2021 00:29:44 -0800 (PST), Wim Ton <wim...@gmail.com
wrote:
On Friday, 24 December 2021 at 15:18:14 UTC+1, jla...@highlandsniptechnology.com wrote:
On Thu, 23 Dec 2021 19:58:41 +0000, Tom Gardner <spam...@blueyonder.co.uk> wrote:
On 23/12/21 19:03, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner <spam...@blueyonder.co.uk> wrote:

<snip>

Not to mention the electric motor, the pulleys, the belts, and the
electric power plant out there somewhere, some of which required
lathes to build.

For somebody who claims to believe in evolution, John Larkin is remarkably unwilling to accept that today\'s lathes were developed from earlier technology by an incremental process - one that we could certainly emulate, if we had to. It might take a while.

--
Bill Sloman, Sydney

 

[Jan Panteltje]

On a sunny day (Mon, 27 Dec 2021 05:10:50 -0800) it happened
jlarkin@highlandsniptechnology.com wrote in
<7lejsg11oent39c8mnbes3055h8hqim3eo@4ax.com>:

Not to mention the electric motor, the pulleys, the belts, and the
electric power plant out there somewhere, some of which required
lathes to build.

Is not all ye need a 3D metal printer ?
https://www.hubs.com/knowledge-base/introduction-metal-3d-printing/

https://www.relativityspace.com/

 

[bitrex]

On 12/23/2021 6:23 PM, Three Jeeps wrote:

On Thursday, December 23, 2021 at 2:03:19 PM UTC-5, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.
Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.
My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.
I\'m really into that kind of thing. In theory at any rate.

i\'ve built my own vacuum tube as an experiment long time ago. I even had (still have?) ideas about starting my own tube fab facility for audio amps. Alas, the tricks of the trade are probably too far buried in the past and the learning curve would be steep. I\'ve read a number of papers from sylvania and rca engineers about some of their discoveries regarding material properties and their effects on tube performance. All of this would have to be \'relearned\'.
In any event, here is a video that I like a lot. It is helpful to have some of the equipment that he does, to build a tube: tack welder, vacuum pump, glass tube lathe, glass furnace, etc. it appears that even his electronic test gear is handmade. A real craftsman....
https://www.youtube.com/watch?v=EzyXMEpq4qw
enjoy
j

There are places in the world where I think they never stopped making
tubes. How\'s your Chinese?

 

[server]

On Thu, 23 Dec 2021 15:23:06 -0800 (PST), Three Jeeps
<jjhudak4@gmail.com> wrote:

On Thursday, December 23, 2021 at 2:03:19 PM UTC-5, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.
Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.
My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.
I\'m really into that kind of thing. In theory at any rate.

i\'ve built my own vacuum tube as an experiment long time ago. I even had (still have?) ideas about starting my own tube fab facility for audio amps. Alas, the tricks of the trade are probably too far buried in the past and the learning curve would be steep. I\'ve read a number of papers from sylvania and rca engineers about some of their discoveries regarding material properties and their effects on tube performance. All of this would have to be \'relearned\'.
In any event, here is a video that I like a lot. It is helpful to have some of the equipment that he does, to build a tube: tack welder, vacuum pump, glass tube lathe, glass furnace, etc. it appears that even his electronic test gear is handmade. A real craftsman....
https://www.youtube.com/watch?v=EzyXMEpq4qw
enjoy
j

I think the cathode coatings were the magical parts.



--

I yam what I yam - Popeye

 

[Three Jeeps]

On Tuesday, December 28, 2021 at 2:03:29 AM UTC-5, bitrex wrote:

On 12/23/2021 6:23 PM, Three Jeeps wrote:
On Thursday, December 23, 2021 at 2:03:19 PM UTC-5, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.
Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.
My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.
I\'m really into that kind of thing. In theory at any rate.

i\'ve built my own vacuum tube as an experiment long time ago. I even had (still have?) ideas about starting my own tube fab facility for audio amps. Alas, the tricks of the trade are probably too far buried in the past and the learning curve would be steep. I\'ve read a number of papers from sylvania and rca engineers about some of their discoveries regarding material properties and their effects on tube performance. All of this would have to be \'relearned\'.
In any event, here is a video that I like a lot. It is helpful to have some of the equipment that he does, to build a tube: tack welder, vacuum pump, glass tube lathe, glass furnace, etc. it appears that even his electronic test gear is handmade. A real craftsman....
https://www.youtube.com/watch?v=EzyXMEpq4qw
enjoy
j


There are places in the world where I think they never stopped making
tubes. How\'s your Chinese?

The quality of my Chinese (and Russian) is about the same as the quality of a lot of their electron tubes-not very good at all ...(some from my own experience, and feedback from ppl in other groups I interact with (e.g. audiophile and ham radio)).

 

[Three Jeeps]

On Tuesday, December 28, 2021 at 10:40:11 AM UTC-5, jla...@highlandsniptechnology.com wrote:

On Thu, 23 Dec 2021 15:23:06 -0800 (PST), Three Jeeps
jjhu...@gmail.com> wrote:

On Thursday, December 23, 2021 at 2:03:19 PM UTC-5, Cursitor Doom wrote:
On Wed, 22 Dec 2021 13:36:14 +0000, Tom Gardner
spam...@blueyonder.co.uk> wrote:

While I have some sympathy for the sentiment, I don\'t agree
with the reasoning and conclusion. OTOH if it is solely for
your sense of achievement, then that\'s a justifiable reason.

But why stop at discrete semiconductors? Why not go a little
further and make your own inductors, capacitors and valves.
Yes, why not? I recall there\'s an old book called something like
\'desert island radio\' which explains how to build a working comms
radio solely from stuff you\'d find washed up on a beach - including
valves. Fascinating.
My father has a book describing how to make your own
car - starting with how to make the tools necessary to make
the car.
I\'m really into that kind of thing. In theory at any rate.

i\'ve built my own vacuum tube as an experiment long time ago. I even had (still have?) ideas about starting my own tube fab facility for audio amps.. Alas, the tricks of the trade are probably too far buried in the past and the learning curve would be steep. I\'ve read a number of papers from sylvania and rca engineers about some of their discoveries regarding material properties and their effects on tube performance. All of this would have to be \'relearned\'.
In any event, here is a video that I like a lot. It is helpful to have some of the equipment that he does, to build a tube: tack welder, vacuum pump, glass tube lathe, glass furnace, etc. it appears that even his electronic test gear is handmade. A real craftsman....
https://www.youtube.com/watch?v=EzyXMEpq4qw
enjoy
j
I think the cathode coatings were the magical parts.
--

I yam what I yam - Popeye

That is what I have gleaned from my readings as well. I don\'t have the indepth physics background to understand the details or the chemistry behind it.

 

[Tabby]

On Saturday, 25 December 2021 at 04:57:32 UTC, palli...@gmail.com wrote:

Tabby wrote:
==============
The vacuum would be the interesting part of that.

It turns out you don\'t need a vacuum to get a thermionic valve to work.

https://odysee.com/@doctorvolt:a/can-we-build-a-tube-amplifier-with-light:1
** The vid does not say the was no vacuum.

did you not watch it? His expermient showed about 50% atmospheric pressure in the crude valve / lightbulb.

Common light bulbs contain low pressure nitrogen but some small types have
a vacuum inside.

IME regular electron tubes ( triodes / pentodes) fail to operate immediately
when air leaks in.


..... Phil

Pressure is not the only issue, IIUC it depends on gas composition too. Air is not good in that respect, N2 is.

 

[Phil Hobbs]

Tabby wrote:

On Saturday, 25 December 2021 at 04:57:32 UTC, palli...@gmail.com wrote:
Tabby wrote:
==============
The vacuum would be the interesting part of that.

It turns out you don\'t need a vacuum to get a thermionic valve to work.

https://odysee.com/@doctorvolt:a/can-we-build-a-tube-amplifier-with-light:1
** The vid does not say the was no vacuum.

did you not watch it? His expermient showed about 50% atmospheric pressure in the crude valve / lightbulb.

Common light bulbs contain low pressure nitrogen but some small types have
a vacuum inside.

IME regular electron tubes ( triodes / pentodes) fail to operate immediately
when air leaks in.


..... Phil

Pressure is not the only issue, IIUC it depends on gas composition too. Air is not good in that respect, N2 is.

Ordinary incandescents have a low-pressure argon fill. Nitrogen is way
too reactive at > 2500 K.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Wed, 29 Dec 2021 13:51:14 -0800 (PST), Tabby <tabbypurr@gmail.com>
wrote:

On Saturday, 25 December 2021 at 04:57:32 UTC, palli...@gmail.com wrote:
Tabby wrote:
==============
The vacuum would be the interesting part of that.

It turns out you don\'t need a vacuum to get a thermionic valve to work.

https://odysee.com/@doctorvolt:a/can-we-build-a-tube-amplifier-with-light:1
** The vid does not say the was no vacuum.

did you not watch it? His expermient showed about 50% atmospheric pressure in the crude valve / lightbulb.

Common light bulbs contain low pressure nitrogen but some small types have
a vacuum inside.

IME regular electron tubes ( triodes / pentodes) fail to operate immediately
when air leaks in.


..... Phil

Pressure is not the only issue, IIUC it depends on gas composition too. Air is not good in that respect, N2 is.

Some linear amplifier tubes had deliberate gas fill, which increased
gain somehow. But it made them slow.

Thyratrons and VR and T/R and krytron tubes of course used inert gas.

https://www.dropbox.com/s/7vkdemdk48k3myd/Kry_Danger.jpg?raw=1

Some demo CRTs had a gas fill that made the beam visible.

Does anyone know what this is?

https://www.dropbox.com/s/np4s7ifgg5f4gbz/DSC01841.JPG?raw=1


--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Three Jeeps]

On Wednesday, December 29, 2021 at 6:13:09 PM UTC-5, John Larkin wrote:

On Wed, 29 Dec 2021 13:51:14 -0800 (PST), Tabby <tabb...@gmail.com
wrote:
On Saturday, 25 December 2021 at 04:57:32 UTC, palli...@gmail.com wrote:
Tabby wrote:
==============
The vacuum would be the interesting part of that.

It turns out you don\'t need a vacuum to get a thermionic valve to work.

https://odysee.com/@doctorvolt:a/can-we-build-a-tube-amplifier-with-light:1
** The vid does not say the was no vacuum.

did you not watch it? His expermient showed about 50% atmospheric pressure in the crude valve / lightbulb.

Common light bulbs contain low pressure nitrogen but some small types have
a vacuum inside.

IME regular electron tubes ( triodes / pentodes) fail to operate immediately
when air leaks in.


..... Phil

Pressure is not the only issue, IIUC it depends on gas composition too. Air is not good in that respect, N2 is.
Some linear amplifier tubes had deliberate gas fill, which increased
gain somehow. But it made them slow.

Thyratrons and VR and T/R and krytron tubes of course used inert gas.

https://www.dropbox.com/s/7vkdemdk48k3myd/Kry_Danger.jpg?raw=1

Some demo CRTs had a gas fill that made the beam visible.

Does anyone know what this is?

https://www.dropbox.com/s/np4s7ifgg5f4gbz/DSC01841.JPG?raw=1
--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

A SWAG, Russian equivalent of half-wave rectifier, equivalent to 6W4 or full wave rectifier, 5YG3 perhaps?

 

[John Larkin]

On Wed, 29 Dec 2021 15:28:48 -0800 (PST), Three Jeeps
<jjhudak4@gmail.com> wrote:

On Wednesday, December 29, 2021 at 6:13:09 PM UTC-5, John Larkin wrote:
On Wed, 29 Dec 2021 13:51:14 -0800 (PST), Tabby <tabb...@gmail.com
wrote:
On Saturday, 25 December 2021 at 04:57:32 UTC, palli...@gmail.com wrote:
Tabby wrote:
==============
The vacuum would be the interesting part of that.

It turns out you don\'t need a vacuum to get a thermionic valve to work.

https://odysee.com/@doctorvolt:a/can-we-build-a-tube-amplifier-with-light:1
** The vid does not say the was no vacuum.

did you not watch it? His expermient showed about 50% atmospheric pressure in the crude valve / lightbulb.

Common light bulbs contain low pressure nitrogen but some small types have
a vacuum inside.

IME regular electron tubes ( triodes / pentodes) fail to operate immediately
when air leaks in.


..... Phil

Pressure is not the only issue, IIUC it depends on gas composition too. Air is not good in that respect, N2 is.
Some linear amplifier tubes had deliberate gas fill, which increased
gain somehow. But it made them slow.

Thyratrons and VR and T/R and krytron tubes of course used inert gas.

https://www.dropbox.com/s/7vkdemdk48k3myd/Kry_Danger.jpg?raw=1

Some demo CRTs had a gas fill that made the beam visible.

Does anyone know what this is?

https://www.dropbox.com/s/np4s7ifgg5f4gbz/DSC01841.JPG?raw=1
--



If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

A SWAG, Russian equivalent of half-wave rectifier, equivalent to 6W4 or full wave rectifier, 5YG3 perhaps?

It doesn\'t have a filament. I\'m guessing it\'s a waveguide radar t/r
switch.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Phil Allison]

Phil Hobbs wrote:

Ordinary incandescents have a low-pressure argon fill.

** No they don\'t - most use Nitrogen.




...... Phil

 

[Phil Allison]

Tabby wrote:
=============

IME regular electron tubes ( triodes / pentodes) fail to operate immediately
when air leaks in.

Pressure is not the only issue, IIUC it depends on gas composition too.

** Really ??

> Air is not good in that respect,

** Shame about the Oxygen.