| spark transmitter | |
| —n | |
| an early type of radio transmitter in which power is generated by discharging a capacitor through an inductor in series with a spark gap | |
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |