[G6Tanuki]

Interesting... I like that ALC circuit.

One trick I've used in the past is "negative cycle loading" on the modulator transformer secondary. The thing that causes 'splatter' is that when the modulator pulls the PA anode voltage going to zero - at which point the modulator is working into an infinite impedance which causes nasty things to happen to the waveform.

"negative cycle loading' uses a diode and series resistor, wired across the modulation transformer, so there's always an appropriate load on the modulator, even on negative peaks, so there's less liklelihood of generating splatter when the modulation-level is high. It's actually possible to achieve over-100%-modulation !!