My present SStran transmitter at 1680 isn’t grounded, but my 3-meter antenna arrangement on the porch is effective and the signal is good for several blocks. I worry about this at times, and when I see white panel trucks I often switch over to the other SStran at 1550, which has a dimmer antenna. That is, a less productive antenna.
If I were to add a (legal) ground plane to the stronger unit, who knows how good it would be. During the bright of day the signal might go a mile. But of course at night there is all the sky interference and no problem.
So at last I come to the point. What if a good ground plane were connected to the transmitter with a potentiometer which could be dialed weaker for daytime but stronger for nightime?
THAT would be like a nightime power boost but it would still be (we hope) within allowed limits.