6F7M

 All the Rogers tubes with the "M" suffix, have an Octal shell base, with 8 contact pins and 1 dowel locator pin. The Museum informations states 7 pins. The M series are all Metal Spray Shielded with contact to pin 1, which serves to ground the metal shell.

There is also not a direct substitute for this tube/valve. A 6P7G may be used if the socket is rewired.

Please see this PDF file for M series Rogers tubes. 

http://pacifictv.ca/schematics/rogerstubedata.pdf

Regards, 

Frank van de Ven

Dear Frank,

Many thanks for the information you sent. The tube base type is now changed to octal. If you have even a pinout diagram to load it would be fine.

Emilio