PHOTO-ELECTRIC "ARC EXTINGUISHER"
Photo Electric Cells
A close-up view of the interior of the recently developed photo-electric "arc extinguisher" installed at the base of 500,000-watt WLW's 831-ft. vertical radiator antenna to protect equipment from lightning.
Here an "electric eye" stands guard, day and night, to protect valuable equipment against lightning as well as to prevent loss of power and interruption in service caused by "power follow-up arcs" across the safety gap which carries the lightning discharge from the tower into the earth.
In the picture is to be seen the photo-electric box, the double shielding against radio frequency, the photronic cell and its associated relays.
The power relay acts directly on the control circuits for the transmitter,
cutting off the plate voltage for a bare fraction of a second thus
extinguishing the arc draining the antenna of power, then again automatically
restoring the plate voltage---all in a split second.
WLW, Cincinnati, Ohio, was the first United States commercial 50 KW station and the only standard broadcast station to ever broadcast at a power of 500KW from 1934 to 1939.
It was also the first to make use of a directional antenna system for skywave radiation control. (WSUN and WFLA, St. Petersburg, FL. shared the first directional antenna system.)
It was called The Nation's Station and was started by Powel Crosley, a grand innovator of products and services from radios to automobiles.
Courtesy Jim Hawkins - firstname.lastname@example.org