cathode current on 3 tubes

General discussion area for tube amps.

Moderators: pompeiisneaks, Colossal

Post Reply
Jered
Posts: 121
Joined: Wed Sep 10, 2008 8:26 am
Location: Orange County CA

cathode current on 3 tubes

Post by Jered »

76 JMP w/EL34's 100 watts. Plate volts = 462
On tubes 1, 2, and 4 I'm getting .037 mA of current. Tube 3 no current and no voltage.
I have swapped tubes, changed the 1 ohm cathode resistor, even changed the tube socket.
Can anybody help me out, I'm stumped. Thanks
pdf64
Posts: 2932
Joined: Sat Mar 12, 2011 9:23 pm
Location: Staffordshire, UK
Contact:

Re: cathode current on 3 tubes

Post by pdf64 »

Is its screen grid resistor good?
Is its heater heating (tube getting hot)?
Vdc on terminals 3,4 and 5?
https://www.justgiving.com/page/5-in-5-for-charlie This is my step son and his family. He is running 5 marathons in 5 days to support the research into STXBP1, the genetic condition my grandson Charlie has. Please consider supporting him!
Jered
Posts: 121
Joined: Wed Sep 10, 2008 8:26 am
Location: Orange County CA

Re: cathode current on 3 tubes

Post by Jered »

Screen resistor. Thank you
pdf64
Posts: 2932
Joined: Sat Mar 12, 2011 9:23 pm
Location: Staffordshire, UK
Contact:

Re: cathode current on 3 tubes

Post by pdf64 »

You're welcome, thanks for the close out report!
https://www.justgiving.com/page/5-in-5-for-charlie This is my step son and his family. He is running 5 marathons in 5 days to support the research into STXBP1, the genetic condition my grandson Charlie has. Please consider supporting him!
Post Reply