I just bought an OM2000+ amplifier from OM-Power.
The amplifier are running flawlessly and I enjoy the easiness and quality.
The tune up are pretty simple and I am sure I do it the right way, to
ensure good and right tune of the amplifier.
But now I am start wondering if I can do it even better.
The tune procedure is straight forward. Use Tune knob for maximum output.
And Load knob to insure the ?I? mark is inside the boundaries. The display
will show > I < when the Load knob is adjusted correctly.
Sometimes the Load knob can be adjusted quite a lot, and still be inside
I can then choose to set the knob in the middle of the two boundaries points.
I think this is the way it should be done.
But then I start wondering about the grid and screen current under this
Will these two values help me find exactly the right spot?
I am not a tube expert and only know the basic things.
The amplifier uses a Tetrode called FU-728.
As I understand it, the grid current will normally be close to 0 mA for my
kind of operation using output power about 1000 W or less.
But the 2. Screen will vary a bit during the tuneup.
It will accept up to 50 mA of screen current, but mostly I see the value
be in the 0 to -15 mA ranges at my power levels.
So the question is now:
Can I use the 2. screen current (or maybe the Grid current) to make a
more precise fine tuning of the amplifier than the broad > I < mark can
Of course I will never go outside the > I <, but I still have some
adjustment window inside the boundaries.
Has anyone any thoughts or tips regarding this matter?
Thomas / OZ1JTE (Denmark).
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