Bottlehead Forum

General Category => General Discussion => Topic started by: najo49 on August 12, 2013, 05:06:46 AM

Title: Why? input resistor
Post by: najo49 on August 12, 2013, 05:06:46 AM

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

Title: Re: Why? input resistor
Post by: Grainger49 on August 12, 2013, 10:57:02 AM

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.

Title: Re: Why? input resistor
Post by: 2wo on August 12, 2013, 11:17:23 AM

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

Title: Re: Why? input resistor
Post by: Doc B. on August 12, 2013, 11:40:59 AM

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.

Title: Re: Why? input resistor
Post by: 2wo on August 12, 2013, 06:46:47 PM

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