[AMPS] The 3/2 Power Law

[Lamb]

Rich:

That is not my definition of the 3/2 power law.  It is Eimac's.

Eimac also says:

"the screen voltage is not critical for most applications and the value used
has been chosen as a convenient value consistent with low driving power and
reasonable screen dissipation.  If lower values of screen voltages are used,
more driving voltage will be required on the grid to obtain the same plate
current.  ... The value of screen voltage can be chosen to suit available
power supplies or amplifier conditions."

In the case of the G2DAF amplifier, the designer simply chose to vary the
voltage on both the control grid and screen grid.

Tubes are used quite frequently with variable voltages applied to two of the
grids - even in designs by Collins and Hallicrafters.  The tubes are
heptodes and the circuits are commonly called mixers.  They are linear and
do not distort.  Of course there are bad mixed designs which do cause
distortion.

 You throw out the 1% distortion figure for the G2DAF design - but that is
just a figure pulled out of your hat.

73,  Colin  K7FM


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