Hello Norm,
(2 questions)
I am rewireing an old tube radio, a Rogers Majestic 10-55. i have the schematics. My question is how do you identify the pin numbers on the tube itself. I have no problem following the pins on paper, when i arrive at the socket i have no positive identification on the tube pins . My tubes are an (80,75M,41M,6A7M,88M). I have found some data on the tubes above, but whitout the 'M' , is there a difference with or whitout the 'M' ?

Can you help
tank you ,
bob

Hi Bob

Look from the bottom, large pins toward you. Start with a large pin on the left. This is #1. Count clockwise until you get to the other large pin. This is the highest number. On an 80 it's 4, the rest 6 or 7.

You are looking at Canadian tube numbers. As far as I know the "S" doesn't make a difference. Ed will know the meaning of "S". I'll forward him a copy of this question.

Norm

:Hello Norm,
:(2 questions)
:I am rewireing an old tube radio, a Rogers Majestic 10-55. i have the schematics. My question is how do you identify the pin numbers on the tube itself. I have no problem following the pins on paper, when i arrive at the socket i have no positive identification on the tube pins . My tubes are an (80,75M,41M,6A7M,88M). I have found some data on the tubes above, but whitout the 'M' , is there a difference with or whitout the 'M' ?
:
:Can you help
:tank you ,
:bob

Sorry about that. I was thinking "S" which usually means shield. I sent your question to Ed. Hopefully he will respond with meaning on "M".

Norm

:Hi Bob
:
: Look from the bottom, large pins toward you. Start with a large pin on the left. This is #1. Count clockwise until you get to the other large pin. This is the highest number. On an 80 it's 4, the rest 6 or 7.
:
: You are looking at Canadian tube numbers. As far as I know the "S" doesn't make a difference. Ed will know the meaning of "S". I'll forward him a copy of this question.
:
:Norm
:
:
:
::Hello Norm,
::(2 questions)
::I am rewireing an old tube radio, a Rogers Majestic 10-55. i have the schematics. My question is how do you identify the pin numbers on the tube itself. I have no problem following the pins on paper, when i arrive at the socket i have no positive identification on the tube pins . My tubes are an (80,75M,41M,6A7M,88M). I have found some data on the tubes above, but whitout the 'M' , is there a difference with or whitout the 'M' ?
::
::Can you help
::tank you ,
::bob

:Sorry about that. I was thinking "S" which usually means shield. I sent your question to Ed. Hopefully he will respond with meaning on "M".

My tubes are an (80,75M,41M,6A7M,88M).

The "M" is a Rogers Spray Shield Tube. They had a mettalic shielding material sprayed over the glass envelope. In many cases they were more common tubes in an octal base with pin one connected to the shield. Other tubes can be used but they may require an adapter, rebasing or a shield added.

Using a Rogers Replacement Tube Chart your 75M is a 6Q7G or 6B6G; 41M a 6K6G; 6A7M a 6A8 or 6A8G & 88M a 6P5G.

I have not yet found a Rogers chart giving specifications and internal structure related to the base pins.

Ed.