Understanding Vacuum Tube Diagrams?

[Chris Cooper]

I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

 

[John Del]

Subject: Understanding Vacuum Tube Diagrams?
From: "Chris Cooper" chrisnews@sc3.net
Date: 11/9/03 7:14 PM Eastern Standard

.. Is there a

simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Try rec.antiques.radio+phono Good group for anything hollow state. The best
thing to do is pick up an RCA Tube Manual (ebay). Lots of very quality info
about vacuum tubes in the front, plus the pin outs, specs, and ratings for each
tube. It's a must have.

John Del
Wolcott, CT

"Nothing is so opportune for tyrants as a people tired of its liberty."
Alan Keyes

(remove S for email reply)

 

[Chaos Master]

I found ancient runes from Chris Cooper[chrisnews@sc3.net] in the floor of
sci.electronics.repair:

I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Ask in rec.antiques.radio+phono, and try to buy an RCA tube manual (from EBay).

--
'You receive a scroll of signature. It says:'
Chaos MasterŽ - Posting from Porto Alegre - Brazil.
E-mail address is yummy food for spammersŽ.

 

[Sam Goldwasser]

What smoked is probably the main filter capacitor. With that
blown out, there is no filtering and thus the hum. Other
electrolytic caps will also need replacement. After that
it may work.

Think of vacuum tubes as enhancement mode MOSFETs in glass
bottles that run on hundreds of volts and like to be warm.
Drain=plate, Source=cathode, Gate=grid. But you probably
won't need to go that deep - replacing the caps may be
all that is needed. Next, would be carbon resistors that
have changed in value. As mentioned in another reply to
your "Reviving 50 year old wire recorder" post, the tubes
are probably good.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.

 

[Robert Baer]

Chris Cooper wrote:

I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

The reference that Jack gave is good for theory, but does not appear
to relate diagram(s) with terminology.
It is getting too late for me to scan some info for you; here is a
"quickie" ASCII pseudo-art:
|
_______ <--- plate (crude)
----- - - - - <---- grid (sort-of crude)
__________
| ^ | <---- cathode (crude)
| / \ <-------- filament
| | |
| | |

Have data on a large number of tubes and can scan what i have for you.
Will see if i can find something better Monday evening (later today).

 

[GPG]

"Chris Cooper" <chrisnews@sc3.net> wrote in message news:<3faed850$0$198$75868355@news.frii.net>...

I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

http://www.allaboutcircuits.com/vol_3/chpt_13/1.html

 

[JURB6006]

Sam;

Oops, that would be depletion mode. No neg on the grid, your tube will be
overdid.

Actually I wonder why they didn't just use cathode plate and grid for FETs.
There are other examples of where they kept an old name for a new item. I can't
think of one right now, but they're out there.

JURB

P.S. Sorry that I am a terrible poet.

 

[Sam Goldwasser]

jurb6006@aol.com (JURB6006) writes:

Sam;

Oops, that would be depletion mode. No neg on the grid, your tube will be
overdid.

Well, except that more positive grid voltage increases current. Or,
the analogy isn't 100 percent.

Actually I wonder why they didn't just use cathode plate and grid for FETs.
There are other examples of where they kept an old name for a new item. I can't
think of one right now, but they're out there.

You don't get Brownie points for reusing old names.

P.S. Sorry that I am a terrible poet.

I hadn't noticed.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.

 

[Zotin Khuma]

jurb6006@aol.com (JURB6006) wrote in message news:<20031111192916.29045.00000027@mb-m12.aol.com>...

Sam;

Oops, that would be depletion mode. No neg on the grid, your tube will be
overdid.

Actually I wonder why they didn't just use cathode plate and grid for FETs.
There are other examples of where they kept an old name for a new item. I can't
think of one right now, but they're out there.

You just gave two examples. After tube technology had been refined, a

"plate" was no longer a simple flat plate, but curved around the
cathode and other electrodes. Grids were no longer grids or meshes,
but wires coiled around the cathode...

JURB

P.S. Sorry that I am a terrible poet.

 

[tiger x]

"Chris Cooper" <chrisnews@sc3.net> wrote in message news:<3faed850$0$198$75868355@news.frii.net>...

I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

A real simple explaination of vacuum tubes:
1. The source of electrons is the cathode.
2. To release electrons, the cathode must be heated by the filament.
3. Released electrons must be attracted & gathered up by the plate.
4. The flow of electrons through the tube is regulated by the control
grid.
5. Any other grids in the tube are for effecient operation of the
tube.
6. The cathode has a negative potential.
7. The plate has a positive potential.
8. The control grid potential varies according to the input signal.
9. On a schematic, the control grid is the bottom grid and enters on
the left of the tube.
10. The signal out of the tube usually leaves via the plate (top), but
may leave via a resistor connected to the cathode (bottom).

Easy as that!

Tiger

 

[Mike Eno]

tigerx813@hotmail.com (tiger x) wrote in message news:<96dbc078.0311130800.23d681c9@posting.google.com>...

"Chris Cooper" <chrisnews@sc3.net> wrote in message news:<3faed850$0$198$75868355@news.frii.net>...
I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

A real simple explaination of vacuum tubes:
1. The source of electrons is the cathode.
2. To release electrons, the cathode must be heated by the filament.
3. Released electrons must be attracted & gathered up by the plate.
4. The flow of electrons through the tube is regulated by the control
grid.
5. Any other grids in the tube are for effecient operation of the
tube.
6. The cathode has a negative potential.
7. The plate has a positive potential.
8. The control grid potential varies according to the input signal.
9. On a schematic, the control grid is the bottom grid and enters on
the left of the tube.
10. The signal out of the tube usually leaves via the plate (top), but
may leave via a resistor connected to the cathode (bottom).

Easy as that!

Tiger

Man you must be a young buck not to know about vacuum tubes or i'm
just
an old #art. Wet behind the ears but interested in 50 year old vintage
electronic devices, all right then.
I know this is a late response but ...
Vacuum tubes share a lot of similarity to Depletion mode MOSFETs in
terms of the design equations. Mind you tubes require much higher DC
operating voltages plus the aformentioned filament juice.
Source Gate Drain are analagous to Cathode Grid Plate.

MENO

 

[Robert Baer]

Mike Eno wrote:

tigerx813@hotmail.com (tiger x) wrote in message news:<96dbc078.0311130800.23d681c9@posting.google.com>...
"Chris Cooper" <chrisnews@sc3.net> wrote in message news:<3faed850$0$198$75868355@news.frii.net>...
I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

A real simple explaination of vacuum tubes:
1. The source of electrons is the cathode.
2. To release electrons, the cathode must be heated by the filament.
3. Released electrons must be attracted & gathered up by the plate.
4. The flow of electrons through the tube is regulated by the control
grid.
5. Any other grids in the tube are for effecient operation of the
tube.
6. The cathode has a negative potential.
7. The plate has a positive potential.
8. The control grid potential varies according to the input signal.
9. On a schematic, the control grid is the bottom grid and enters on
the left of the tube.
10. The signal out of the tube usually leaves via the plate (top), but
may leave via a resistor connected to the cathode (bottom).

Easy as that!

Tiger

Man you must be a young buck not to know about vacuum tubes or i'm
just
an old #art. Wet behind the ears but interested in 50 year old vintage
electronic devices, all right then.
I know this is a late response but ...
Vacuum tubes share a lot of similarity to Depletion mode MOSFETs in
terms of the design equations. Mind you tubes require much higher DC
operating voltages plus the aformentioned filament juice.
Source Gate Drain are analagous to Cathode Grid Plate.

MENO

....and....i, as well as others posted labelled drawings and links to
numerous references.
Dead issue by now.

 

On Tue, 02 Dec 2003 09:32:16 GMT, Robert Baer
<robertbaer@earthlink.net> wrote:

Mike Eno wrote:

tigerx813@hotmail.com (tiger x) wrote in message news:<96dbc078.0311130800.23d681c9@posting.google.com>...
"Chris Cooper" <chrisnews@sc3.net> wrote in message news:<3faed850$0$198$75868355@news.frii.net>...
I've got an old wire record I'm trying to revive (see my "Reviving 50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

A real simple explaination of vacuum tubes:
1. The source of electrons is the cathode.
2. To release electrons, the cathode must be heated by the filament.
3. Released electrons must be attracted & gathered up by the plate.
4. The flow of electrons through the tube is regulated by the control
grid.
5. Any other grids in the tube are for effecient operation of the
tube.
6. The cathode has a negative potential.
7. The plate has a positive potential.
8. The control grid potential varies according to the input signal.
9. On a schematic, the control grid is the bottom grid and enters on
the left of the tube.
10. The signal out of the tube usually leaves via the plate (top), but
may leave via a resistor connected to the cathode (bottom).

Easy as that!

Tiger

Man you must be a young buck not to know about vacuum tubes or i'm
just
an old #art. Wet behind the ears but interested in 50 year old vintage
electronic devices, all right then.
I know this is a late response but ...
Vacuum tubes share a lot of similarity to Depletion mode MOSFETs in
terms of the design equations. Mind you tubes require much higher DC
operating voltages plus the aformentioned filament juice.
Source Gate Drain are analagous to Cathode Grid Plate.

MENO

...and....i, as well as others posted labelled drawings and links to
numerous references.
Dead issue by now.

Being an old fart who worked with lots of tubes in the good old days.
I'd appreciate these links reposted, since I didnt see these messages.
Thanks

 

[Jack]

http://www.oldtuberadio.com/tubes/theory.htm



"Chris Cooper" <chrisnews@sc3.net> wrote in message
news:3faed850$0$198$75868355@news.frii.net...

I've got an old wire record I'm trying to revive (see my "Reviving 50+
year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes. Is there
a
simple explanation (online preferably) that talks about the "standard
symbols" used in vacuum tube internals?

Thanks!
Chris

 

[Roy Wiggins]

Just a small contribution from another elder! Basically the current from the
cathode to the anode (plate) is modulated by small signals on the grid:
since the current flowing through the valve also flows through the anode
resistor (or cathode resistor) the voltage drop across either of them
reflects the current variations - which, (because of the valve) are
amplified. There, I didn't think I would ever need to say that again.
Regards and have a great Xmas.
Roy
<me@my.com> wrote in message
news:sb1qsvkva70ejgcmd5hs6ojcl2pfn8aee8@4ax.com...

On Tue, 02 Dec 2003 09:32:16 GMT, Robert Baer
robertbaer@earthlink.net> wrote:

Mike Eno wrote:

tigerx813@hotmail.com (tiger x) wrote in message
news:<96dbc078.0311130800.23d681c9@posting.google.com>...
"Chris Cooper" <chrisnews@sc3.net> wrote in message
news:<3faed850$0$198$75868355@news.frii.net>...
I've got an old wire record I'm trying to revive (see my "Reviving
50+ year
old Wire Recorder" post), one of the problems is that I don't quite
understand how to interpret the schematics for the vacuum tubes.
Is there a
simple explanation (online preferably) that talks about the
"standard
symbols" used in vacuum tube internals?

Thanks!
Chris

A real simple explaination of vacuum tubes:
1. The source of electrons is the cathode.
2. To release electrons, the cathode must be heated by the filament.
3. Released electrons must be attracted & gathered up by the plate.
4. The flow of electrons through the tube is regulated by the control
grid.
5. Any other grids in the tube are for effecient operation of the
tube.
6. The cathode has a negative potential.
7. The plate has a positive potential.
8. The control grid potential varies according to the input signal.
9. On a schematic, the control grid is the bottom grid and enters on
the left of the tube.
10. The signal out of the tube usually leaves via the plate (top),
but
may leave via a resistor connected to the cathode (bottom).

Easy as that!

Tiger

Man you must be a young buck not to know about vacuum tubes or i'm
just
an old #art. Wet behind the ears but interested in 50 year old vintage
electronic devices, all right then.
I know this is a late response but ...
Vacuum tubes share a lot of similarity to Depletion mode MOSFETs in
terms of the design equations. Mind you tubes require much higher DC
operating voltages plus the aformentioned filament juice.
Source Gate Drain are analagous to Cathode Grid Plate.

MENO

...and....i, as well as others posted labelled drawings and links to
numerous references.
Dead issue by now.

Being an old fart who worked with lots of tubes in the good old days.
I'd appreciate these links reposted, since I didnt see these messages.
Thanks