[Roger A. Modjeski]

Here is a 33 minuite documentary on the famous Blackburn Factory. Its starts off a little slow but the factory pictures are very good and typical of how tubes were made in the USA. It appears they made a lot of their own equipment, some of which looks rather Rube Goldberg but so did the machinery I saw at the Sylvania factory in Pennsylvania.

The sad thing is that while this factory was ever and proudly expanding, transistor production had already started in earnest and their days were numbered. Of course, at that time it was thought the transistor would never overtake the tube, early transistors couldn't do much.  Perhaps if they had not gotten so big they might still be around. This was a very big operation. Much larger than the Sylvania factory which was our last to build and last to close.

I happen to have a Mullard Radio Valve Manual from 1957 (around the time of this video) which does include 19 pages on transistor theory and application contrasted to 102 pages on valve theory and application. They were making some primitive transistors for small signal applications as did Sylvania, Tungsol, Philco and many other US tube makers who later dropped out of that field. The Mullard range of tubes was not nearly so large as RCA and other US makers and even though Television is given as a big reason for increased production, the range of TV tubes by Mullard is very small where the range of TV tubes in the US was very large.

Here's the link on youtube.  http://www.youtube.com/watch?v=GDvF89Bh27Y&feature=g-hist

[Rocket_Ronny]

 


Rocket_Bottle Head_Ronny

[Russell Dawkins]

I hope the equipment was not trashed but is still in use somewhere.  It's sad to think of all that innovative energy going to waste. The timing seemed painfully bad, almost as if they were in denial about the potential of the transistor.
I wonder how the machining equipment was controlled. This was pre-robotics - at least pre-computer control, I think, although I seem to recall that IBM style punch cards were used for some machine control functions for which a computer would be used these days.

[Roger A. Modjeski]

Those machines and the ones I saw at Sylvania were pure mechanical and ingenious. There was a half horsepower motor at the bottom of most and lots of gears, cams and levers. The machines were all made in house. However in most of Europe, Phillips made the machines and supplied the tooling, designs and materials. Which is why a Yugo 12AX7 looks just like a Telefunken except for the diamond on the bottom of the glass.

[Rclark]

I love old documentaries. After viewing this one, I understand why good tubes are very expensive. They are incredibly complicated to make. I always thought the prices were somewhat arbitrary. I couldn't believe how many steps had to be taken in their construction and how many pretty sophisticated looking machines were needed for the job (make it color and hidef and you'd think you were looking at industrial robots, some of them). And one realizes just how state of the art these things were (tubes) back then.

Thanks for posting that 

[Ericus Rex]

I just now found the time to watch the full video.  FASCINATING!!!!!!  Thanks so much for sharing, Roger.

And now I know how to correctly pronounce 'Mullard'   

[Berndt]

That is pretty amazing. Some of those machines looked like a setup nightmare.
More human touch involved than i would have thought.

[Roger A. Modjeski]

There was even more human touch in the EI factory in Yugoslavia when I visited in 1990. Mullard had automated more than most.  The British are famous for making complex machinery, it may look funny but it works... with lots of tinkering.

[HAL]

If you take a Mullard ECC83 dual triode and put a Mullard OC44 germanium transistor in front of it, you have most of the original sound of early british rock recordings.  Thank goodness that they existed side-by-side! 

[Roger A. Modjeski]

If you take a Mullard ECC83 dual triode and put a Mullard OC44 germanium transistor in front of it, you have most of the original sound of early british rock recordings.  Thank goodness that they existed side-by-side! 

Do you have a schematic of this?

[HAL]

This is for an electric guitar.  The original device was called a Dallas Rangemaster treble booster.  Very simple single transistor HP filter.   The schematic is easily searchable in Google.  Use that to drive a Mullard ECC83 in the first stage of a Laney or Marshall amp, you have the early british rock guitar sound.