DK23 Dekatron Do-Hickie - All 4 Modes

All 4 operation modes: (1)Slinky - like the old toy. Ask someone over 45. (2)Gauge - responds to ambient sound. Pendulum, when quiet. (3)Radar - like old radar display. (4)Jellyfish . Dekatrons are up/down counting tubes, that predate ICs. Only one dot is glowing at anyone time. These patterns are generated with the help of a modern computer chip.