Valve identification - UK Vintage Radio Repair and Restoration Discussion Forum

Edwar65 · 8th Jan 2017, 4:37 pm

Hi, I have a number of what look like EL84 and ECC83 valves that I wish to use but have lost their markings. Is there a proven method of identification that one can use to help with this?
Thanks.

Edward Huggins · 8th Jan 2017, 4:48 pm

Well the envelope is much longer on the EL84 and you can only see the one eletrode assembly. The ECC83 is quite stubby and you can clearly see the 2 triode assemblys side by side.

AC/HL · 8th Jan 2017, 4:49 pm

Have a look here: http://www.r-type.org/

Sideband · 8th Jan 2017, 4:55 pm

EL 84's are quite easy to identify. ECC83's can be a little more difficult. At one time, the ECC83 had a shorter anode than an ECC82. I have however got several ECC83's that look identical to ECC82. Some members familiar with factory markings may have a sure-fire method of identification. Why not start off by posting some good close-up pictures?.

Of course your EL84's could be UL84's (or even PL84's). No way of telling those apart by looks.

m0cemdave · 8th Jan 2017, 6:37 pm

Have they lost *all* their markings? If they were made by any of the Philips factories dotted around the world, there would have been a set of numbers near the valve base that can be decoded to give the valve type. They often remain after all other print has rubbed off.

Backtoreality · 9th Jan 2017, 11:39 pm

Hi,
Mullard code rX for EL84, I6 for ECC83. Google "Mullard Factory Valve Codes" for a full list. Shame nobody has done an Excel file for them. Or have they?
David

PJL · 10th Jan 2017, 12:10 am

I have a copy of the Philips code list in pdf format which has been reproduced in machine readable characters rather than a scan. Not sure where it came from.

There are various tricks for revealing worn away printing. Use a strong light source and look at the reflective light or breath on the valve to create a light mist.

AC/HL · 10th Jan 2017, 1:51 am

There are a couple of lists, and they can be a bit fiddly to translate. I find it easier to work out the probables, there'll only be a couple, and look the code up for confirmation.

8th Jan 2017, 4:37 pm	#1
Edwar65 Pentode Join Date: Dec 2012 Location: Cardiff, UK. Posts: 211	Valve identification Hi, I have a number of what look like EL84 and ECC83 valves that I wish to use but have lost their markings. Is there a proven method of identification that one can use to help with this? Thanks.

8th Jan 2017, 4:48 pm	#2
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,335	Re: Valve identification Well the envelope is much longer on the EL84 and you can only see the one eletrode assembly. The ECC83 is quite stubby and you can clearly see the 2 triode assemblys side by side. __________________ Edward.

8th Jan 2017, 4:49 pm	#3
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Valve identification Have a look here: http://www.r-type.org/

8th Jan 2017, 4:55 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,577	Re: Valve identification EL 84's are quite easy to identify. ECC83's can be a little more difficult. At one time, the ECC83 had a shorter anode than an ECC82. I have however got several ECC83's that look identical to ECC82. Some members familiar with factory markings may have a sure-fire method of identification. Why not start off by posting some good close-up pictures?. Of course your EL84's could be UL84's (or even PL84's). No way of telling those apart by looks. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

8th Jan 2017, 6:37 pm	#5
m0cemdave Octode Join Date: Feb 2009 Location: Bletchley, Buckinghamshire, UK. Posts: 1,223	Re: Valve identification Have they lost all their markings? If they were made by any of the Philips factories dotted around the world, there would have been a set of numbers near the valve base that can be decoded to give the valve type. They often remain after all other print has rubbed off.

9th Jan 2017, 11:39 pm	#6
Backtoreality Hexode Join Date: Oct 2007 Location: Ossett, West Yorkshire, UK. Posts: 406	Re: Valve identification Hi, Mullard code rX for EL84, I6 for ECC83. Google "Mullard Factory Valve Codes" for a full list. Shame nobody has done an Excel file for them. Or have they? David

10th Jan 2017, 12:10 am	#7
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Valve identification I have a copy of the Philips code list in pdf format which has been reproduced in machine readable characters rather than a scan. Not sure where it came from. There are various tricks for revealing worn away printing. Use a strong light source and look at the reflective light or breath on the valve to create a light mist. Last edited by PJL; 10th Jan 2017 at 12:15 am.

10th Jan 2017, 1:51 am	#8
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Valve identification There are a couple of lists, and they can be a bit fiddly to translate. I find it easier to work out the probables, there'll only be a couple, and look the code up for confirmation.