Why? input resistor

[najo49]

In my 45 amp direct coupled,C4s, with MQ iron. What is the resistor for, the 326 ohm that is in line with the input for.. Not the screen resistor but the inline one. Thanks Jan Olsen

 

[Grainger49]

Jan,

Do you mean from the hot lead to ground?  If so, that is the load across which the source develops its voltage.  An open circuit isn't friendly to sources here.

 

[2wo]

That sounds like a level matching resistor. If you wanted a bit more gain or just want to you could jumper that out...John

 

[Doc B]

Screen resistor? Not likely since the tubes don't have screens. That is probably a grid stopper resistor. It keeps RFI out of the tube's grid.

 

[2wo]

I misread the value (326 ohm), as Doc said it is a grid stopper and I would leave it...John