In the vacuum tube era, a tube (e.g. 6V6) was usually produced by several
manufacturers. I am not sure of how things actually went, but I would say
that a manufacturer initially designed the tube and put it on the market,
and subsequently other manufacturers "copied" the tube. But how did they
actually copy it? Just by reverse engineering (e.g. measuring dimensions and
distances among electrodes)? Or instead the original manufacturer published
the detailed tube design so allowing others to produce it? The first option
seems more likely to me, as manufacturers should have little interest in
helping others to replicate a tube.

The same question applies to solid-state devices, but in that case I would
expect that reproducing a device having (almost) the same characteristics
through a reverse engineering process would be very hard, if not
impoossible.

Does any one know how things go in practice?

73

Tony I0JX
Rome, Italy

Antonio I0JX wrote:
In the vacuum tube era, a tube (e.g. 6V6) was usually produced by several
manufacturers. I am not sure of how things actually went, but I would say
that a manufacturer initially designed the tube and put it on the market,
and subsequently other manufacturers "copied" the tube. But how did they
actually copy it? Just by reverse engineering (e.g. measuring dimensions and
distances among electrodes)? Or instead the original manufacturer published
the detailed tube design so allowing others to produce it? The first option
seems more likely to me, as manufacturers should have little interest in
helping others to replicate a tube.

The same way it happens today in the solid state era! One company introduces
an IC, and a second company pays a licensing fee to second source the design.
A third company makes a "compatible" device through reverse-engineering and
a fourth company makes an "improved" version with additional features which
meets the specifications on the datasheet but may have something totally
different than the original inside the package.

Also, just because a company is selling it doesn't mean they made it. Most
of the compactron types were only made by GE... they were sold by a lot of
different companies but even the Sylvania ones came from the GE factory.

The same question applies to solid-state devices, but in that case I would
expect that reproducing a device having (almost) the same characteristics
through a reverse engineering process would be very hard, if not
impoossible.

Depends on the device. Just about everybody making a 2N2222 is using a
die that looks the same; they are all copying one another. Intel made
the 8080, but then Zilog made a compatible microprocessor, the Z-80,
that was totally different inside. It wasn't a copy at all. Much of it
has to do with the complexity of the device. The 2N2222 is not so hard to
reverse-engineer, whereas the latest Intel microprocessor is.

Does any one know how things go in practice?

Much worse now that we have so much production in China where intellectual
property regulations are lax at best. Now you can contract a fab line to
make an IC for you, and then after the run is finished they keep an extra
set of masks so they can keep making the part for your competititors...
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

I think 'copying' would have had legal complications. Usually there was
a licensing arrangement involved. In such a case I imagine the license
holder would have provided detailled information.
Of course Brand B could come up with its on version and get it
registered as their own tube. But the differences between it and Brand
A would have to be sufficient so that they didn't get sued.

RCA was by far the largest license holder and they weren't hesitant to
use their lawyers!

-Bill



Antonio I0JX wrote:
In the vacuum tube era, a tube (e.g. 6V6) was usually produced by
several manufacturers. I am not sure of how things actually went, but I
would say that a manufacturer initially designed the tube and put it on
the market, and subsequently other manufacturers "copied" the tube. But
how did they actually copy it? Just by reverse engineering (e.g.
measuring dimensions and distances among electrodes)? Or instead the
original manufacturer published the detailed tube design so allowing
others to produce it? The first option seems more likely to me, as
manufacturers should have little interest in helping others to replicate
a tube.

The same question applies to solid-state devices, but in that case I
would expect that reproducing a device having (almost) the same
characteristics through a reverse engineering process would be very
hard, if not impoossible.

Does any one know how things go in practice?

73

Tony I0JX
Rome, Italy

Bill M wrote:
I think 'copying' would have had legal complications. Usually there was
a licensing arrangement involved. In such a case I imagine the license
holder would have provided detailled information.

It sure did have legal complications, and RCA loved suing people! They
had more lawyers than engineers, it seemed! When the beam power tubes
came out, their patent infringment folks were working three shifts, I think.

Of course Brand B could come up with its on version and get it
registered as their own tube. But the differences between it and Brand
A would have to be sufficient so that they didn't get sued.

Which is why you get the 25L6, which sounds like it's a 6L6, but it's really
not.

RCA was by far the largest license holder and they weren't hesitant to
use their lawyers!

They were the Microsoft of their day.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Sat, 18 Oct 2014 09:24:33 +0200, Antonio I0JX wrote:

In the vacuum tube era, a tube (e.g. 6V6) was usually produced by
several manufacturers. I am not sure of how things actually went, but I
would say that a manufacturer initially designed the tube and put it on
the market, and subsequently other manufacturers "copied" the tube. But
how did they actually copy it? Just by reverse engineering (e.g.
measuring dimensions and distances among electrodes)? Or instead the
original manufacturer published the detailed tube design so allowing
others to produce it? The first option seems more likely to me, as
manufacturers should have little interest in helping others to replicate
a tube.

The same question applies to solid-state devices, but in that case I
would expect that reproducing a device having (almost) the same
characteristics through a reverse engineering process would be very
hard, if not impoossible.

Does any one know how things go in practice?

73

Tony I0JX Rome, Italy

While some copying may have happened, a lot of tubes weren't copied.
Look at a number of any of the common tubes, like 6SN7. There is a large
variety of internal construction.

And, as someone else mentioned, there was re-branding, where one company
made tubes with someone else's name on them. Every company did that,
both as a supplier and a buyer.

--
Jim Mueller

To get my real email address, replace wrongname with dadoheadman.
Then replace nospam with fastmail. Lastly, replace com with us.

On Sat, 18 Oct 2014 17:25:36 -0400, Bill M
wrote:

I think 'copying' would have had legal complications. Usually there was
a licensing arrangement involved. In such a case I imagine the license
holder would have provided detailled information.
Of course Brand B could come up with its on version and get it
registered as their own tube. But the differences between it and Brand
A would have to be sufficient so that they didn't get sued.

RCA was by far the largest license holder and they weren't hesitant to
use their lawyers!

-Bill

A: Because it messes up the order in which people normally read text.

Q: Why is top-posting such a bad thing?

A: Top-posting.

Q: What is the most annoying thing in usenet?

Antonio I0JX wrote:
In the vacuum tube era, a tube (e.g. 6V6) was usually produced by
several manufacturers. I am not sure of how things actually went, but I
would say that a manufacturer initially designed the tube and put it on
the market, and subsequently other manufacturers "copied" the tube. But
how did they actually copy it? Just by reverse engineering (e.g.
measuring dimensions and distances among electrodes)? Or instead the
original manufacturer published the detailed tube design so allowing
others to produce it? The first option seems more likely to me, as
manufacturers should have little interest in helping others to replicate
a tube.

The same question applies to solid-state devices, but in that case I
would expect that reproducing a device having (almost) the same
characteristics through a reverse engineering process would be very
hard, if not impoossible.

Does any one know how things go in practice?

73

Tony I0JX
Rome, Italy


--
Why don't fundamentalists push for a revisionist taxonomy that places
bats among the birds instead of the mammals? Or to have the schools
give equal time to the "demon theory of disease" whenever they discuss
he "germ theory of disease"?

RCA was built from the surplus of GE and Westinghouse.

So I don't think RCA was in any position to sue the General for anything.

Everyone in those days was in the commercial electronics business, small radios and communications and later television.

Other companies such as Rayethon, Murata Erie, Sylvania came along later.

Most of the residents of my small town migrated to Emporium and St. Mary's PA during WW II to get jobs in the small tube manufacturer plants.
Brookville PA, along with Dubois and Bradford also had tube plants.

Most of those plants shifted production to Powder Metals after the war.
Some upgraded their plants to produce light bulbs and other electronics.

Barry OGrady wrote:

A: Top-posting.

Q: What is the most annoying thing in usenet?

No, Usenet trolls are the most annoying thing. Get a life.

"Scott Dorsey" wrote in message
...

Intel made
the 8080, but then Zilog made a compatible microprocessor, the Z-80,
that was totally different inside.

ISTR that the Z80 was designed by an Intel team, but when Intel opted
instead for the 8085 as the next step after the 8080, that the Z80 team
decamped and set up Zilog.

(Info gained when on an Intel training course in Swindon in 1981)

The solution, of course, is to post both at the top, and also at the bottom
in your socially-minded attempt to make everyone happy!

"Bill M" wrote in message
...
Barry OGrady wrote:

A: Top-posting.

Q: What is the most annoying thing in usenet?

No, Usenet trolls are the most annoying thing. Get a life.

The solution, of course, is to post both at the top, and also at the bottom
in your socially-minded attempt to make everyone happy!