MV 41 valve?

[SurreyNick]

Here's a conundrum which remains unsolved.

I have picked up a Marconiphone Model 55 portable receiver dated 1929 and in it is a valve which I can find no reference of!

It appears to be a MV 41 (pictured) and is in substitute of the H210 which acts as the leaky grid detector. Has anyone ever heard of the MV 41? There's nothing at all on Radio Museum or The National Valve Museum, which really surprised me as that's a first for me!

The only other writing on the glass envelope is:

VI No. 74
GPO
SERIAL No

Does anyone here know anything about this valve?

Nick
   

[ppppenguin]

There is some info on GPO valve numbering but I can't find a comprehensive cross reference online. This page gives some idea of how the numbering system works.

http://www.r-type.org/exhib/aaj0005.htm

[SurreyNick]

It's a good start Jeffrey. If it was never intended for public sale then it might have been a replacement put in by someone who had access to these valves and subsequently it may be impossible to find any reference.
Nick.

[pwdrive]

Can't help with that valve Nick, according to the Marconi Valve Data the 55 receiver uses three HL2's, one L210 and one P215.

Lawrence.

[Terry]

We had a customer who worked for the GPO and owned a valve attache case portable - I can't remember which but it was a reasonable size.

When I opened it up I was rather surprised to find that the AD35 LT battery had been replaced with a rather large GPO single cell. It was just a wee bit too fat for the space available - which he has resolved by chiselling away a layer or two in the bottom of the plywood case in order to make a depression running the length of the cell ...!

[ppppenguin]

Partial GPO cross reference chart here:
http://www.audiotubes.com/VT%20crossreference.htm

Not sure how useful it is in this case.

[SurreyNick]

I think I'm happy enough that it was a valve equivalent made for the GPO and therefore there is no reference and no reason why there should need to be either. In my '55' it's in place of the H210.
Thanks for your help guys, I now know where it came from and so my question has been answered
Nick

[ppppenguin]

Nick, on a related topic ISTR that you once published a huge spreadsheet of valve equivalents. Something that was potentially very useful for people who were cataloguing their own valve collections. Would you be willing to publish the latest version here?

[SurreyNick]

I did and here it is Jeffrey.
I don't claim credit for the raw data, just the format. The raw data was available open source on the internet. I just changed the format and put it into a spreadsheet. So I can't guarantee the data's accuracy.
Nick

  Valve Tube Equivalents.xlsx (Size: 891.2 KB / Downloads: 27)

[ppppenguin]

Thank you. I'm sure it will be useful to me and to other GVR members. Please don't blame Nick for any errors. It would be miraculous if there were none.