GPO VT valve numbers - UK Vintage Radio Repair and Restoration Discussion Forum

M0FYA Andy · 17th Jun 2011, 2:50 pm

Has anyone got an equivalents list between GPO VT valve numbers and their normal commercial numbering please?

(Note that the GPO VT valve numbering system was not the same as the American military VT valve numbering system).

I have a VT91 I would like to identify. It has a British 5-pin base, and was made by M-O. It has 'VT91' inside the usual M-O oval 'Made & patented in England' logo, and on the opposite side of the bulb

G 41
GPO 234
VT No. 91

Any ideas?

Many thanks,

Andy

Marconi_MPT4 · 17th Jun 2011, 3:07 pm

Hi Andy,

According to 'Service Valve Equivalents' book published by the RSGB in 1962,

GPO valve type VT91 is a CV1038 which is either a MHL4 (MOV) or 41MLF (Cossor) and has an english B5 base.

Cheers

Rich

AVO_VCM163 · 17th Jun 2011, 4:12 pm

See Page 16 of the CV register HERE.

Normally the USA VT seris are written VT-nn and the UK ones VTnn to differentiate.
Roy

M0FYA Andy · 17th Jun 2011, 4:16 pm

Hi Rich and Roy,

Very many thanks!

Andy

G4XWDJim · 17th Jun 2011, 5:55 pm

Andy,

I have a specific GPO page or two in one of my data books I can let you have in a few days if no-one else sends it first.

Jim

M0FYA Andy · 17th Jun 2011, 6:19 pm

Jim,

Thanks! i'm sure I have seen one somewhere, but I'm blowed if I can find it. Sometimes one can have just too much information at one's fingertips!

Andy

Tim · 17th Jun 2011, 8:17 pm

There's a little "Post office VT numbers" table on the last page of the AVO valve tester book.

Alistair D · 24th Oct 2014, 12:50 pm

Just found this page while looking for something else.

http://frank.pocnet.net/more.html

Edit. Also this http://frank.pocnet.net/other/nobr.html

Al

17th Jun 2011, 2:50 pm	#1
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	GPO VT valve numbers Has anyone got an equivalents list between GPO VT valve numbers and their normal commercial numbering please? (Note that the GPO VT valve numbering system was not the same as the American military VT valve numbering system). I have a VT91 I would like to identify. It has a British 5-pin base, and was made by M-O. It has 'VT91' inside the usual M-O oval 'Made & patented in England' logo, and on the opposite side of the bulb G 41 GPO 234 VT No. 91 Any ideas? Many thanks, Andy

17th Jun 2011, 3:07 pm	#2
Marconi_MPT4 Heptode Join Date: Mar 2011 Location: Dorset, UK. Posts: 521	Re: GPO VT valve numbers Hi Andy, According to 'Service Valve Equivalents' book published by the RSGB in 1962, GPO valve type VT91 is a CV1038 which is either a MHL4 (MOV) or 41MLF (Cossor) and has an english B5 base. Cheers Rich

17th Jun 2011, 4:12 pm	#3
AVO_VCM163 Retired Dormant Member Join Date: Mar 2008 Location: Hampshire, UK. Posts: 297	Re: GPO VT valve numbers See Page 16 of the CV register HERE. Normally the USA VT seris are written VT-nn and the UK ones VTnn to differentiate. Roy

17th Jun 2011, 4:16 pm	#4
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: GPO VT valve numbers Hi Rich and Roy, Very many thanks! Andy

17th Jun 2011, 5:55 pm	#5
G4XWDJim Octode Join Date: Oct 2008 Location: Littlehampton, West Sussex, UK. Posts: 1,465	Re: GPO VT valve numbers Andy, I have a specific GPO page or two in one of my data books I can let you have in a few days if no-one else sends it first. Jim

17th Jun 2011, 6:19 pm	#6
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: GPO VT valve numbers Jim, Thanks! i'm sure I have seen one somewhere, but I'm blowed if I can find it. Sometimes one can have just too much information at one's fingertips! Andy

17th Jun 2011, 8:17 pm	#7
Tim Dekatron Join Date: Jan 2003 Location: Bradford on Avon, Wiltshire, UK. Posts: 3,310	Re: GPO VT valve numbers There's a little "Post office VT numbers" table on the last page of the AVO valve tester book. __________________ "Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly."

24th Oct 2014, 12:50 pm	#8
Alistair D Nonode Join Date: Jan 2010 Location: Edinburgh, UK. Posts: 2,008	Re: GPO VT valve numbers Just found this page while looking for something else. http://frank.pocnet.net/more.html Edit. Also this http://frank.pocnet.net/other/nobr.html Al __________________ I won't tell you how I discovered that. Last edited by Alistair D; 24th Oct 2014 at 12:56 pm.