valve type systems - UK Vintage Radio Repair and Restoration Discussion Forum

adibrook · 19th Apr 2006, 11:32 pm

It seems that there are several alrge scale valve naming systems around.

Thers the ''common'' (mullard) one with letters representing heater power and functions, such as ECC83 = 6.3v-triode-triode-83.

Also thers the american system which i dont quiet understand, although the 1st number gives the approx heater voltage i think. (but why is it just 6 rather than 6.3? For simplicity? I dont quiet get what the letters mean. But i'm sure thers some kind of list of letters and their meaning.

Also i'm aware of several other systems used in early valves and other things.

but what's the X17 and the Z17 for example? I dont think they follow the normal mullard system, but not the american one either. Is there a nother majour system in use?

paulsherwin · 20th Apr 2006, 12:45 am

Hi Adi. The Pro-Electron system used by Mullard and Philips was only one of a large number of valve numbering systems used by many manufacturers. It became widely used in Europe after WW2 because it is obviously sensible, but many manufacturers carried on using private systems including Mazda and Cossor.

I believe the American system has something to do with the number of elements in the valve. It's basically an approximate indication of heater voltage followed by a type code followed by the element count, so you have 12AU7 (ECC82), 12AX7 (ECC83) etc.

Best regards, Paul

Paul Stenning · 20th Apr 2006, 7:46 am

There is some information on the different type number schemes here http://www.vintage-radio.com/repair-...numbering.html

19th Apr 2006, 11:32 pm	#1
adibrook Retired Dormant Member Join Date: Dec 2004 Location: Weymouth, Dorset, UK. Posts: 377	valve type systems It seems that there are several alrge scale valve naming systems around. Thers the ''common'' (mullard) one with letters representing heater power and functions, such as ECC83 = 6.3v-triode-triode-83. Also thers the american system which i dont quiet understand, although the 1st number gives the approx heater voltage i think. (but why is it just 6 rather than 6.3? For simplicity? I dont quiet get what the letters mean. But i'm sure thers some kind of list of letters and their meaning. Also i'm aware of several other systems used in early valves and other things. but what's the X17 and the Z17 for example? I dont think they follow the normal mullard system, but not the american one either. Is there a nother majour system in use?

20th Apr 2006, 12:45 am	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,970	Re: valve type systems Hi Adi. The Pro-Electron system used by Mullard and Philips was only one of a large number of valve numbering systems used by many manufacturers. It became widely used in Europe after WW2 because it is obviously sensible, but many manufacturers carried on using private systems including Mazda and Cossor. I believe the American system has something to do with the number of elements in the valve. It's basically an approximate indication of heater voltage followed by a type code followed by the element count, so you have 12AU7 (ECC82), 12AX7 (ECC83) etc. Best regards, Paul

20th Apr 2006, 7:46 am	#3
Paul Stenning Administrator Join Date: Dec 2002 Location: Cardiff Posts: 9,073	Re: valve type systems There is some information on the different type number schemes here http://www.vintage-radio.com/repair-...numbering.html __________________ Paul Stenning Forum Admin/Owner and BVWS Webmaster