Is this pinout correct on this 5840 tube?

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pucho812

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I took a clip from a schematic of a piece I am working on.  I want to confirm that I have the correct pins labeled for this 5840 tube. I have been over the data sheets and I just want to confirm I have this correct based on what the data sheet says and what I have labeled as the schematic.

According to the data sheet
pin 1 is grid one,
pins 2,4,8 is cathode and gride #3?
pins 3 & 6 are heaters
Pin 5 is there plate
and Pin 7 is grid Screen 2
 

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pucho812 said:
According to the data sheet
pin 1 is grid one,
pins 2,4,8 is cathode and gride #3?
pins 3 & 6 are heaters
Pin 5 is there plate
and Pin 7 is grid Screen 2

Sounds right to me. Not sure what you're doing with the schematic though.. but I'm guessing you're just asking about the pinout.
 

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I'm helping a friend sort out some issues.
He provided the schematic  I attached and  I added the PIN numbers  in red.  I am just double checking that I labeled things correctly as I am not sure what to do with PIN 8 if anything based on the schematic snippet?
 
Yeah... Weird looking. I've personally never seen one. But, as you said, 8 is 2 is 4 in this case so, it's already doing something.  Maybe some kind of pentode running as triode deal in this circuit....
 
Not sure what you are asking.2, 8 and 4 are connected internally. 

I don't know what you're circuit is and ,even then, not sure I could help...lol

Have to admit though, I was confused because of G2 and G3 tied together but that doesn't mean anything..... it's obviously done sometimes
 
But that circuit shows grid 2 and 3 strapped to anode (plate), and as grid 3 is internally strapped to cathode, you basically have a short circuit valve (tube)!  :eek:
 
radardoug said:
Ah, so you stole the circuit from Oliver, who put a cunning error in the circuit, ensuring it will never work! Hehe!

nothing stolen here, he is working on a mic kit and asked me some questions.  My buddy also picked up parts from them and they sold him the 5840 tube so I am not sure if that is a mistake or not.
 
You need to connect 4,5,7 together. this makes the tube operate as a triode. Pin 1 is grid input. Wire heater to 6.3vdc & either 2 or 8 are cathode connection points.
 
Bill Wilson said:
You need to connect 4,5,7 together. this makes the tube operate as a triode. Pin 1 is grid input. Wire heater to 6.3vdc & either 2 or 8 are cathode connection points.

Yes but internally pins 4  & 8 are cathode and gride 3 due to internal connections. I asked the source to see what they say, that seems to be the only hold up on this...

 

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