CV1820 valve? - UK Vintage Radio Repair and Restoration Discussion Forum

QWENIX · 25th Mar 2018, 10:32 pm

A friend of mine found a CV valve which is numbered 1820. But this one is B7G miniature based.

I did following research:

Internet says octal base and equivalents 1H5GT en DAC32 maybe VT-25.

Next research: In my valves handbooks.
Dutch handbooks Muiderkring Electronic tubes and transistors handbook.
2 x CV valves register air ministry hardcopy
Preferred valve list.
Babani encyclopedia all 3 books red green blue
The Universal Electronic vade mecum polish edition
Colomor Elsevier edition of the Electronic Universal Vade Mecum
the Red Books DVD Electronic Valve Specifications EVS.

I have my thoughts.....

Anyone a clue ??

ms660 · 26th Mar 2018, 9:30 am

CV820?

Lawrence.

ukcol · 26th Mar 2018, 9:44 am

Yes, CV820 looks quite possible.

The CV820 has a centre tapped heater so there should be continuity between pins 1, 5 and 7 if it is indeed an 820.

ms660 · 26th Mar 2018, 9:58 am

CV820>>>AM ref?:

https://www.langrex.co.uk/products/3...0-mullard-nos/

Lawrence.

M0FYA Andy · 26th Mar 2018, 11:31 am

Lawrence, I'm not sure what you are asking about the AM Reference. Earlier on, valves were given Stores References in Section 10E of A.P.1086, but after the CV numbering came into existence, they allocated 10CV/ numbers. Which I agree is inconsistent as this looks like a sub-section of 10C which is for capacitors and chokes, not valves.

So the AM reference of the CV820 will be 10CV/820. Maybe somebody misread the / for a 1

Andy

ms660 · 26th Mar 2018, 11:40 am

Quote:

Originally Posted by M0FYA Andy

So the AM reference of the CV820 will be 10CV/820. Maybe somebody misread the / for a 1 Andy

That was my thinking from what was written on the box in the link.

Lawrence.

QWENIX · 29th Mar 2018, 4:30 pm

Thank you guys for answering my question. It was a misprint but i just wanted to have that small piece of extra info. Well I think ive got it. To you all:

25th Mar 2018, 10:32 pm	#1
QWENIX Pentode Join Date: Jan 2006 Location: Amsterdam, The Netherlands Posts: 180	CV1820 valve? A friend of mine found a CV valve which is numbered 1820. But this one is B7G miniature based. I did following research: Internet says octal base and equivalents 1H5GT en DAC32 maybe VT-25. Next research: In my valves handbooks. Dutch handbooks Muiderkring Electronic tubes and transistors handbook. 2 x CV valves register air ministry hardcopy Preferred valve list. Babani encyclopedia all 3 books red green blue The Universal Electronic vade mecum polish edition Colomor Elsevier edition of the Electronic Universal Vade Mecum the Red Books DVD Electronic Valve Specifications EVS. I have my thoughts..... Anyone a clue ?? Attached Thumbnails

26th Mar 2018, 9:30 am	#2
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: CV1820 valve? CV820? Lawrence.

26th Mar 2018, 9:44 am	#3
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Re: CV1820 valve? Yes, CV820 looks quite possible. The CV820 has a centre tapped heater so there should be continuity between pins 1, 5 and 7 if it is indeed an 820.

26th Mar 2018, 9:58 am	#4
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: CV1820 valve? CV820>>>AM ref?: https://www.langrex.co.uk/products/3...0-mullard-nos/ Lawrence. Last edited by ms660; 26th Mar 2018 at 10:07 am.

26th Mar 2018, 11:31 am	#5
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: CV1820 valve? Lawrence, I'm not sure what you are asking about the AM Reference. Earlier on, valves were given Stores References in Section 10E of A.P.1086, but after the CV numbering came into existence, they allocated 10CV/ numbers. Which I agree is inconsistent as this looks like a sub-section of 10C which is for capacitors and chokes, not valves. So the AM reference of the CV820 will be 10CV/820. Maybe somebody misread the / for a 1 Andy

29th Mar 2018, 4:30 pm	#7
QWENIX Pentode Join Date: Jan 2006 Location: Amsterdam, The Netherlands Posts: 180	Re: CV1820 valve? Thank you guys for answering my question. It was a misprint but i just wanted to have that small piece of extra info. Well I think ive got it. To you all: