• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

EMI tubes (British made)

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EMI tubes (British made)

I have a question about EMI tube/valve manufacturing. I found an EMI photomultiplier tube (PMT) in my Perkin Elmer 202 UV-Vis spectrophotometer and it says it was made in England. Did EMI make any other tubes, such as audio tubes? Did EMI actually make tubes or did they just relabel tubes made by other companies, ie. Mullard tubes? Is this the same EMI that made the plate reverb system and was/is involved in the recording industry?


You can see the partly faded EMI logo in the picture below. On the tag it says:

Type 9592B
S/No. 27119
MADE IN GREAT BRITAIN

Near the pins is another tag taped to the tube that is that says: 27119

There's also some brown-black writing on the glass envelope that says:

EMI ELECTRON CS LTD.
VALVE DIVISION
BURY STREET RUISLIP
MIDDLESEX
MADE IN ENGLAND


More pictures here http://www.geocities.com/antiquesci/PE124/EMI-PMT.html
 

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Ex-Moderator
Joined 2003
Yes, it's Electrical & Musical Industries. Yes, they made valves. PMTs are rather specialised, and used to be used extensively in broadcast television for transferring film to television (telecines). If EMI bought any valves in, they would have been from firms they had a television link such as RCA or Marconi-Osram (the 405 line television system was originally known as the Marconi-EMI system).
 

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I found some EMI patents that are relevant to what I'm talking about. You can look them up here:

http://ep.espacenet.com/numberSearch?locale=en_ep

http://www.pat2pdf.org/

(need Adobe Acrobat Reader)


US 3039016 Electrodes
PMT EMI

US 2001005 Method of and means for recording sound
EMI

US 2100259 Television
EMI

US 2107519 Electron discharge device
EMI

US 2124394 Picture and sound transmission
EMI

US 2210034 Electron multipler
EMI

US 2786888 Deflection and accelerating voltage correction circuits for flying spot film scanners
EMI

US 2836755 Electron multipliers
EMI

US 2841728 Electron multipliers
EMI

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These plate reverb patents were assigned to another company.

US 2923369 Acoustic reverberation arrangements
plate


US 3719905 REVERBERATION DEVICE
plate, theory, reduced dimensions


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Some spring reverb patents if anyone's interested.

US 2982819 Artificial reverberation apparatus
hanging springs

US 3106610 Artificial reverberation unit
springs
 
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