In cign--(at)--elios.phy.OhioU.Edu (Dave Cigna) writes:
>I prefer a one ohm resistor in the cathode circuit too, but you guys seem
>to be missing the fact that in any case, if you have screen grid resistors
>in place, then you can measure the voltage drop across them and calculate
>the screen current. A little arithmetic never hurt anyone.

I just read thru most of this thread and I was wondering when someone
was going to mention this. Your amp had better have screen resistors, so
measure the voltage across 'em and make note of it. Even if they change
a bit, the deviation will not form a large percentage of the overall cath.
current. So...the high voltage stuff can be checked once and done with.

At that point you can provide 1 ohm resistors with chassis-mounted jacks
so the amp's owner can monitor the bias with a Radio Shack meter without
acquiring a Don King hairdo.

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Also...
Regarding the 'quality of the news group':
What if you bought a book that was supposed to be about guitar amps,
but was in reality a lot of mindless bitching about Kurt Cobain?
I think those in this group have a right to expect posts being close
to topic. Otherwise, why would anyone with reasonable technical
skill want to pay be here?

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And last...
My compliments, Mr. Cigna, on the cool tone control response program.
Good work.

Mark Garvin

Index:

AB crossover	Amp Classes Defined	Amp Classes Explained	Amp Mods Harmful
Bass Cutoff Frequencies	Bias adjust safeguard	Bias Cathode Resistors	Bias Shift
Biasing methods	Biasing	Channel Switching LDRs	Choke Input Filter
Circuit Memory	circuits	Drop B+	Eyelet board
Fender Response Curves	FET source follower	Filament Cathode Ground	Fixed to Cathode Bias
FM Transmitter Voltages	Grid Blocking	Identify Power Trans Leads	Load Impedance
LV No PC boards	Output impedances	PC Boards	PCB amp problems
Phase Inverter Resistors	Pilot Light Tone	Rectifier voltage drops	Resistor Design
Resistor Max Voltage	Resistor noise	Reverb Tank Types	Reverb tanks
Screen Grids	Standby Switch Ratings	Standby switches	TAME Digest
Tone Circuits	Transformer Design Book	Transformer Info	Transformer Placement
Zener Voltage Drop