Ralph Mowery wrote:

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** Heathkit ? 1kW ??

FYI, there is ZERO phase angle between the V and I drawn by an amplifier.


I don't know how accurate it was, but a few years ago I replaced the
tubes in my Sb-200 amp. I wanted to see how efficient the amp was.

I had an el cheepo China meter that showed Volts, amps, watts. The
volts did check with my Fluke meter.

With a bathroom heater the watts and V times A were vey close maybe
because of the very small fan motor. When hooked to my amp and loaded
to 600 to 700 watts RF out the watts and V times A were way off. One
showed maybe 80 to 90 $ different depending on the loading. I took that
to be the inductance of the transformer causing that.

I don't know enough AC theory to explain it if there is not more than a
ZERO phase angle.


** The PF of general electronic load is about 0.5 to 0.65.

But that has NOTHING to do with transformer inductance ( a myth) or phase angle and cannot be fixed with a capacitor across the supply.

It has everything to do with the current wave be made up of pulses ( at double the supply frequency ) and so not being a sine wave.

The "true rms" value of a pulsed current is higher than a comparable steady sine current.



..... Phil