Were 6Q7G valves ever coated? - UK Vintage Radio Repair and Restoration Discussion Forum

Neil Purling · 6th Aug 2012, 10:49 am

I have EBC33 examples and their envelopes have the external metalised coating.
Is this not really necessary, as I have not encountered a 6Q7 that has been externally coated.

Mr Moose · 6th Aug 2012, 12:17 pm

Hello,

The 6Q7 is an American valve and they normally have metal versions, rather than the European metallized versions, if a screened valve is required; or a glass (6Q7G or 6Q7GT) valve could be used in a screening can.

The 6Q7 is a metal screened (as opposed to a metallized) valve, see http://www.radiomuseum.org/tubes/tube_6q7.html
The 6Q7G and 6Q7GT are unscreened glass valves , see http://www.radiomuseum.org/tubes/tube_6q7g.html
There is also the 6Q7GM which is metallized, see http://www.radiomuseum.org/tubes/tube_6q7gm.html
And the 6Q7MG see with a metal coat, see http://www.radiomuseum.org/tubes/tube_6q7mg.html

Yours, Richard

Peter.N. · 6th Aug 2012, 4:22 pm

There were a few purpose made metal cased American valves but otherwise as Richard says.

Peter

AC/HL · 7th Aug 2012, 12:30 am

That Swedish one looks suspiciously like a re-badged EBC33.

Neil Purling · 7th Aug 2012, 9:30 pm

I have seen the metal coat examples. I believe the ones I saw were French.

6th Aug 2012, 10:49 am	#1
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Were 6Q7G valves ever coated? I have EBC33 examples and their envelopes have the external metalised coating. Is this not really necessary, as I have not encountered a 6Q7 that has been externally coated.

6th Aug 2012, 12:17 pm	#2
Mr Moose Octode Join Date: Jul 2008 Location: Gloucestershire, UK. Posts: 1,043	Re: Were 6Q7G valves ever coated? Hello, The 6Q7 is an American valve and they normally have metal versions, rather than the European metallized versions, if a screened valve is required; or a glass (6Q7G or 6Q7GT) valve could be used in a screening can. The 6Q7 is a metal screened (as opposed to a metallized) valve, see http://www.radiomuseum.org/tubes/tube_6q7.html The 6Q7G and 6Q7GT are unscreened glass valves , see http://www.radiomuseum.org/tubes/tube_6q7g.html There is also the 6Q7GM which is metallized, see http://www.radiomuseum.org/tubes/tube_6q7gm.html And the 6Q7MG see with a metal coat, see http://www.radiomuseum.org/tubes/tube_6q7mg.html Yours, Richard Last edited by Mr Moose; 6th Aug 2012 at 12:30 pm.

6th Aug 2012, 4:22 pm	#3
Peter.N. Dekatron Join Date: Jul 2008 Location: Charmouth, Dorset, UK. Posts: 3,601	Re: Were 6Q7G valves ever coated? There were a few purpose made metal cased American valves but otherwise as Richard says. Peter

7th Aug 2012, 12:30 am	#4
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Were 6Q7G valves ever coated? That Swedish one looks suspiciously like a re-badged EBC33.

7th Aug 2012, 9:30 pm	#5
Neil Purling Nonode Join Date: Jul 2005 Location: Hull, East Yorkshire, UK. Posts: 2,087	Re: Were 6Q7G valves ever coated? I have seen the metal coat examples. I believe the ones I saw were French.