Svar till: CW or MCW?

[rich.g.williams]

Hi Jörg (and Fredrik),

I can see how the keying method would be called a “magnetic amplifier” because it uses the 3KWatt DC to control the 200KWatt SAQ carrier.

That said, if I understand correctly, its not a magnetic amplifier really. As I understand it the 3KWatt DC completely pushes the “output transformer” cores metal into saturation and the cores metal can no longer couple the Alternator output into the Antenna. This can happen to any inductor or transformer whenever there is a DC current component present in any winding.

I would guess that the 250 Volt 12 Amp max DC current is passed through a series resistor (that gets pretty hot) to limit the current to the 12 Amp maximum. So when the Morse Key is released the 250 Volt is applied across the resistor and an output transformer winding in series, the current flowing starts at 0 Amp and builds up very quickly to 12 Amp and the output transformer core is by then saturated. Similarly when the Morse Key is pressed the DC current flow is stopped (diverted and absorbed) and the magnetic core very quickly moves out of saturation.

A very similar principle is used by Fluxgate Compasses, in this case the Earth’s static field pushes the small core into varying partial saturation.