What meter for Bias?

[WildOne]

I want to add a panel meter on my new amp project for bias. Anyone know what kind of meter i am looking for and maybe where they are available?

Thanks
WO

[knoberik]

You really need to see tube current, not bias voltage. Analogue amp-meter gauge connected straight to the tube cathode or digital mV-meter over cathode resistor will do. If using 1 Ohm cathode resistor, then 1mA = 1mV.

Originally Posted by WildOne

I want to add a panel meter on my new amp project for bias. Anyone know what kind of meter i am looking for and maybe where they are available?

Thanks
WO

[WildOne]

Thanks

If i go with the digital mV-meter what size?

0-75Mv? 0-200Mv?

Thanks
WO

[Alastair E]

Originally Posted by WildOne

Thanks

If i go with the digital mV-meter what size?

0-75Mv? 0-200Mv?

Thanks
WO

Well--Whats the nominal bias Current of your valves...??

[quikie22]

M = Mega, m=mili...

size depends on what your sense resistor value will be and the current you are sensing.. keeping it simple at 1ohm sense R.. then choose a meter with voltage that will cover the estimated bias/idle current...

[knoberik]

I use 200mV digital meters.

If using 1 Ohm cathode resistor, then 1mV = 1mA. In this case 200mV mV-meter supports current measurements up to 200mA.

If using 0,1 Ohm cathode resistor, then 1mV = 10 mA, this supports larger currents, up to 2A. Usually there is possibility to remove the decimal point from mV-meter, so the reading will be as the current.

Originally Posted by WildOne

Thanks
If i go with the digital mV-meter what size?
0-75Mv? 0-200Mv?

Thanks
WO