Pretty interesting vid if you have about 17 minutes to kill.

http://blog.makezine.com/archive/200...ccum_tube.html

Dave

Great video presentation, much better than any episode of the How It's Made
TV show that I've seen.
Fire, and lots of shop-made metal parts to be observed. Resistance spot
welding and induction heating, too.

It looked as though the equipment he was using was all shop-made, and at the
end of the video, it shows the guy making parts in a well equipped machine
shop.

FWIW, and contrary to popular belief, contained vacuum doesn't have to be
performed by using a vacuum pump.
When a vessel is heated to a high temperature, it's fairly well evacuated of
air. Sealing the vessel/envelope while it's hot can be performed fairly
easily when the envelope is glass, whether it's a small vacuum tube or a
CRT.

A simple grade-school demonstration in the early 1960s involved dropping a
small burning piece of paper into a milk bottle, and placing a hardboiled
egg on top of the opening, as the flame went out.
That was a time when milk came in a heavy reuseable bottle with a large
neck.
Of course, this didn't demonstrate the evacuation process by external heat,
it was just fun to see.

WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
Pretty interesting vid if you have about 17 minutes to kill.

http://blog.makezine.com/archive/200...ccum_tube.html

Dave

On Sep 19, 1:03*am, wrote:
Pretty interesting vid if you have about 17 minutes to kill.

http://blog.makezine.com/archive/200...ccum_tube.html

Dave

I liked how he imitated a doctor delivering a baby when he held up the
"newborn" upside down by one of the leads. -- Funny!

Wild_Bill wrote:
Great video presentation, much better than any episode of the How It's
Made TV show that I've seen.

I'll second that opinion...

Fire, and lots of shop-made metal parts to be observed. Resistance spot
welding and induction heating, too.

It looked as though the equipment he was using was all shop-made, and at
the end of the video, it shows the guy making parts in a well equipped
machine shop.

FWIW, and contrary to popular belief, contained vacuum doesn't have to
be performed by using a vacuum pump.
When a vessel is heated to a high temperature, it's fairly well
evacuated of air. Sealing the vessel/envelope while it's hot can be
performed fairly easily when the envelope is glass, whether it's a small
vacuum tube or a CRT.

A simple grade-school demonstration in the early 1960s involved dropping
a small burning piece of paper into a milk bottle, and placing a
hardboiled egg on top of the opening, as the flame went out.

The egg was sans shell as I recall.

That was a time when milk came in a heavy reuseable bottle with a large
neck.
Of course, this didn't demonstrate the evacuation process by external
heat, it was just fun to see.

I also remember the teacher collapsing (imploding?) a gallon tin can
with condensing steam by screwing the cap on the can after boiling a
little water in it.


WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...

Pretty interesting vid if you have about 17 minutes to kill.

http://blog.makezine.com/archive/200...ccum_tube.html

Dave



Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.98*10^14 fathoms per fortnight.

On Sep 19, 1:03*am, wrote:
Pretty interesting vid if you have about 17 minutes to kill.

http://blog.makezine.com/archive/200...ccum_tube.html

Dave

The person in the video is Claude Paillard, F2FO:
http://translate.google.com/translat...hl=en&ie=UTF-8

This post brings me back a bit. One of my friends fathers worked for a
vacuum tube manufacturer (Eimac) and would patently explain any question
presented by one of the boys hanging out in his garage.

I remember him explaining that the silver you saw on the inside of a tube
was the last step in removing all of the oxygen from the tube. When the
tube had been pumped down and sealed off, there was a heating element that
would vaporize a but of silver and the vapor would bond with the remaining
oxygen and condense on the inside of the tube. The term for this was a
getter as it would "get" the last bits of stray oxygen.

This was the same guy that thought us how to drill a hole in glass using a
copper tube and a slurry of abrasive restrained by a clay dam. He also
explained why it was a real pain to drill stainless steel and showed us how
it could be done by holding pressure on the quill of the drill press with
one hand and using the other hand to turn the pulley. No destroyed bit and
no work hardening of the stainless.


--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.
"Wild_Bill" wrote in message
...
Great video presentation, much better than any episode of the How It's
Made
TV show that I've seen.
Fire, and lots of shop-made metal parts to be observed. Resistance spot
welding and induction heating, too.

It looked as though the equipment he was using was all shop-made, and at
the
end of the video, it shows the guy making parts in a well equipped machine
shop.

FWIW, and contrary to popular belief, contained vacuum doesn't have to be
performed by using a vacuum pump.
When a vessel is heated to a high temperature, it's fairly well evacuated
of
air. Sealing the vessel/envelope while it's hot can be performed fairly
easily when the envelope is glass, whether it's a small vacuum tube or a
CRT.

A simple grade-school demonstration in the early 1960s involved dropping a
small burning piece of paper into a milk bottle, and placing a hardboiled
egg on top of the opening, as the flame went out.
That was a time when milk came in a heavy reuseable bottle with a large
neck.
Of course, this didn't demonstrate the evacuation process by external
heat,
it was just fun to see.

WB
.........
metalworking projects
www.kwagmire.com/metal_proj.html


wrote in message
...
Pretty interesting vid if you have about 17 minutes to kill.

http://blog.makezine.com/archive/200...ccum_tube.html

Dave

On Sat, 20 Sep 2008 13:43:09 -0700, Roger Shoaf wrote:
This post brings me back a bit. One of my friends fathers worked for a
vacuum tube manufacturer (Eimac) and would patently explain any question
presented by one of the boys hanging out in his garage.

I remember him explaining that the silver you saw on the inside of a
tube was the last step in removing all of the oxygen from the tube.
When the tube had been pumped down and sealed off, there was a heating
element that would vaporize a but of silver and the vapor would bond
with the remaining oxygen and condense on the inside of the tube. The
term for this was a getter as it would "get" the last bits of stray
oxygen.

I don't know whether silver is ever used as a getter; the usual
getter is barium. http://en.wikipedia.org/wiki/Vacuum_tube
says zirconium is used in large tubes, and phosphorus was used in
some early tubes.

This was the same guy that thought us how to drill a hole in glass using
a copper tube and a slurry of abrasive restrained by a clay dam. He
also explained why it was a real pain to drill stainless steel and
showed us how it could be done by holding pressure on the quill of the
drill press with one hand and using the other hand to turn the pulley.
No destroyed bit and no work hardening of the stainless.

--
jiw

The silver looking stuff in Tubes is mercury.
The getter was a pan of mercury and it was excited by an RF probe after
the tube was sealed on the line to oxidize itself so when the filament
is heated to red to red-white in color it would last many hours.

I've made tubes that you could pass a lunch box through without touching
sides. The filament was as large as a pencil. It was a research tube.
The largest I have put my hand on was 15 feet tall. The smallest was just
larger than a pencil eraser.

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


James Waldby wrote:
On Sat, 20 Sep 2008 13:43:09 -0700, Roger Shoaf wrote:
This post brings me back a bit. One of my friends fathers worked for a
vacuum tube manufacturer (Eimac) and would patently explain any question
presented by one of the boys hanging out in his garage.

I remember him explaining that the silver you saw on the inside of a
tube was the last step in removing all of the oxygen from the tube.
When the tube had been pumped down and sealed off, there was a heating
element that would vaporize a but of silver and the vapor would bond
with the remaining oxygen and condense on the inside of the tube. The
term for this was a getter as it would "get" the last bits of stray
oxygen.

I don't know whether silver is ever used as a getter; the usual
getter is barium. http://en.wikipedia.org/wiki/Vacuum_tube
says zirconium is used in large tubes, and phosphorus was used in
some early tubes.

This was the same guy that thought us how to drill a hole in glass using
a copper tube and a slurry of abrasive restrained by a clay dam. He
also explained why it was a real pain to drill stainless steel and
showed us how it could be done by holding pressure on the quill of the
drill press with one hand and using the other hand to turn the pulley.
No destroyed bit and no work hardening of the stainless.



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In article ,
"Martin H. Eastburn" wrote:

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

The years of the 807 and 6146, 12A7, etc. etc?

John Husvar wrote:

In article ,
"Martin H. Eastburn" wrote:

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

The years of the 807 and 6146, 12A7, etc. etc?


More like the 4CX250 family. I ran over 800 watts out of a pair in a
TV Transmitter on Ch. 8.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

On Sat, 20 Sep 2008 21:46:42 -0500, "Martin H. Eastburn"
wrote:

The silver looking stuff in Tubes is mercury.
The getter was a pan of mercury and it was excited by an RF probe after
the tube was sealed on the line to oxidize itself so when the filament
is heated to red to red-white in color it would last many hours.

I've made tubes that you could pass a lunch box through without touching
sides. The filament was as large as a pencil. It was a research tube.
The largest I have put my hand on was 15 feet tall. The smallest was just
larger than a pencil eraser.

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

Martin

Martin H. Eastburn

Mercury? I would think that any residual Hg in the tube would vaporize
with the heat of operation, presenting a real problem for the electron
emission getting to the plate. Any "gas" in a vacuum tube is usually
considered a bad thing.

I think that I had heard years ago that barium was most commonly
used.You did mention that it was oxidized, but I thought the oxide was
red in color. Most of my work with tubes was in lower power stuff, up
to, say, 6GL6, etc.

I remember there were some diodes (high current ?) that used mercury
in their operation, though.

The big ones are cool; I keep trying to get the engineer at our local
University station to save a defunct transmitter tube for me (I do a
weekly volunteer stint there as a DJ).

Joe

As I recall there were various elements (or compounds) used as getters . . .

Some of the old broadcast tubes were quite large. I went into one of the border Mexican stations,
you know the type that was directional into N. America. One the roof was a large wooden-slatted
cooling tower. Inquiring as if I had stumbled into an old-fashioned ice plant by mistake, I was
informed that the tower was cooling water used in the plate circuit of the final amplifiers.

Bob Swinney
"Joe" wrote in message news On Sat, 20 Sep 2008 21:46:42 -0500, "Martin H. Eastburn"
wrote:

The silver looking stuff in Tubes is mercury.
The getter was a pan of mercury and it was excited by an RF probe after
the tube was sealed on the line to oxidize itself so when the filament
is heated to red to red-white in color it would last many hours.

I've made tubes that you could pass a lunch box through without touching
sides. The filament was as large as a pencil. It was a research tube.
The largest I have put my hand on was 15 feet tall. The smallest was just
larger than a pencil eraser.

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

Martin

Martin H. Eastburn

Mercury? I would think that any residual Hg in the tube would vaporize
with the heat of operation, presenting a real problem for the electron
emission getting to the plate. Any "gas" in a vacuum tube is usually
considered a bad thing.

I think that I had heard years ago that barium was most commonly
used.You did mention that it was oxidized, but I thought the oxide was
red in color. Most of my work with tubes was in lower power stuff, up
to, say, 6GL6, etc.

I remember there were some diodes (high current ?) that used mercury
in their operation, though.

The big ones are cool; I keep trying to get the engineer at our local
University station to save a defunct transmitter tube for me (I do a
weekly volunteer stint there as a DJ).

Joe

On Sat, 20 Sep 2008 21:46:42 -0500, Martin H. Eastburn wrote:

-- snip --

Eimac was the maker of Power transmitting tubes. I think of pyramid
tubes and potato sized kilowatt transmitting rubes. TV and Radio as
well as military used them. I think I have one or two in the shop.
They used to advertise in ELECTRONICS magazine in the 50's. Those were
the years.

Martin

-- snip --

Was??

http://www.eimac.com/division.cfm/9

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

The really big ones - Ignatrons (sp) used arc points and were the
10,000 amp class of SCR's. Still in use I suspect - plating plants....

Many power amp tubes of all sort used the stuff - I have some in the shop.
The internal arcing - getting the getter to activate and vaporize onto
the walls was done by an RF probe that injected through the glass
(acting like a cap). Many power rectifiers and power triodes (like two
fists on top of each other) had Hg in the current flow.

I might have one of those in the shop, but seems to me it was replaced
with solid state.

Heat in the normal tube wasn't enough to activate atom mobility.

It is a small point that is in a cup and then coats a small area of the glass.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Joe wrote:
On Sat, 20 Sep 2008 21:46:42 -0500, "Martin H. Eastburn"
wrote:

The silver looking stuff in Tubes is mercury.
The getter was a pan of mercury and it was excited by an RF probe after
the tube was sealed on the line to oxidize itself so when the filament
is heated to red to red-white in color it would last many hours.

I've made tubes that you could pass a lunch box through without touching
sides. The filament was as large as a pencil. It was a research tube.
The largest I have put my hand on was 15 feet tall. The smallest was just
larger than a pencil eraser.

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

Martin

Martin H. Eastburn

Mercury? I would think that any residual Hg in the tube would vaporize
with the heat of operation, presenting a real problem for the electron
emission getting to the plate. Any "gas" in a vacuum tube is usually
considered a bad thing.

I think that I had heard years ago that barium was most commonly
used.You did mention that it was oxidized, but I thought the oxide was
red in color. Most of my work with tubes was in lower power stuff, up
to, say, 6GL6, etc.

I remember there were some diodes (high current ?) that used mercury
in their operation, though.

The big ones are cool; I keep trying to get the engineer at our local
University station to save a defunct transmitter tube for me (I do a
weekly volunteer stint there as a DJ).

Joe


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The largest ones I saw were those Klystrons that people climb into
in order to change the filament. They had a swimming pool that had
'blue' water within as a cooling start - and used an isolation tank
to transfer the heat to a pool attached to a large body of water.

Naturally the blue was nuclear in nature.
Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Robert Swinney wrote:
As I recall there were various elements (or compounds) used as getters . . .

Some of the old broadcast tubes were quite large. I went into one of the border Mexican stations,
you know the type that was directional into N. America. One the roof was a large wooden-slatted
cooling tower. Inquiring as if I had stumbled into an old-fashioned ice plant by mistake, I was
informed that the tower was cooling water used in the plate circuit of the final amplifiers.

Bob Swinney
"Joe" wrote in message news On Sat, 20 Sep 2008 21:46:42 -0500, "Martin H. Eastburn"
wrote:

The silver looking stuff in Tubes is mercury.
The getter was a pan of mercury and it was excited by an RF probe after
the tube was sealed on the line to oxidize itself so when the filament
is heated to red to red-white in color it would last many hours.

I've made tubes that you could pass a lunch box through without touching
sides. The filament was as large as a pencil. It was a research tube.
The largest I have put my hand on was 15 feet tall. The smallest was just
larger than a pencil eraser.

I taught Tube design (circuit) and later, taught EE's who knew tubes
solid state. So I had to know both designs and show relationships.

Eimac was the maker of Power transmitting tubes. I think of pyramid tubes
and potato sized kilowatt transmitting rubes. TV and Radio as well as
military used them. I think I have one or two in the shop. They used
to advertise in ELECTRONICS magazine in the 50's. Those were the years.

Martin

Martin H. Eastburn

Mercury? I would think that any residual Hg in the tube would vaporize
with the heat of operation, presenting a real problem for the electron
emission getting to the plate. Any "gas" in a vacuum tube is usually
considered a bad thing.

I think that I had heard years ago that barium was most commonly
used.You did mention that it was oxidized, but I thought the oxide was
red in color. Most of my work with tubes was in lower power stuff, up
to, say, 6GL6, etc.

I remember there were some diodes (high current ?) that used mercury
in their operation, though.

The big ones are cool; I keep trying to get the engineer at our local
University station to save a defunct transmitter tube for me (I do a
weekly volunteer stint there as a DJ).

Joe



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---= - Total Privacy via Encryption =---

I don't know if they are THE maker they were at one time.
So many companies are into the game now.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Tim Wescott wrote:
On Sat, 20 Sep 2008 21:46:42 -0500, Martin H. Eastburn wrote:

-- snip --
Eimac was the maker of Power transmitting tubes. I think of pyramid
tubes and potato sized kilowatt transmitting rubes. TV and Radio as
well as military used them. I think I have one or two in the shop.
They used to advertise in ELECTRONICS magazine in the 50's. Those were
the years.

Martin

-- snip --

Was??

http://www.eimac.com/division.cfm/9



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