16 April 19

The FCC allows phone operation on 40 meters, which had been CW only.
The 15 meter band is opened. The Advanced Class is withdrawn from new
applicants, although present holders can continue to renew, and the “exclusive”
75 & 20 meter phone bands are opened to Generals & Conditionals. Everyone, Conditional & above, has the same privileges.

15 April 19

After Hertz received his professorship at Karlsruhe he was experimenting with a pair of Riess spirals in the autumn of 1886 when he noticed that discharging a Leyden jar into one of these coils would produce a spark in the other coil. With an idea on how to build an apparatus, Hertz now had a way to proceed with the “Berlin Prize” problem of 1879 on proving Maxwell’s theory (although the actual prize had expired uncollected in 1882).  He used a Ruhmkorff coil-driven spark gap and one-meter wire pair as a radiator. Capacity spheres were present at the ends for circuit resonance adjustments. His receiver was a simple half-wave dipole antenna with a micrometer spark gap between the elements. This experiment produced and received what are now called radio waves in the very high frequency range.

Click Here for more from Wikipedia ….. Also … American Association for the Advancement of Science