

hold:(2nd)     shows signs at 0.1
		blows up at   1.0

hold+spring:
	impulsive source
		hold 0.1  spring 0.01    blows up
		hold 0.1  spring 0.01    blows up
		hold 0.1  spring 0.001   blows up
		hold 0.0001  spring 0.0001   blows up
		hold=0.00001  spring=0.00001 works

		hold=1.0 spring=0.3     not much effect at all

	vibroseis
		hold=1.0 spring=0.3     works shows effect
