The June 1942 issue of Service magazine carried this ad for an air raid alarm to be added to any radio.  It noted that the first sign of an air raid would often be local radio stations leaving the air, lest they serve as a beacon for incoming bombers.  If you were listening to the radio during the day, you would know immediately.  But at night, with the radio off, you would be caught unaware.

With this home alert, you would leave the radio on standby, and if the station you were tuned to left the air, this would be the sign of a possible air raid.  The ad noted that during air raid alarms in Los Angeles, radios equipped with this device sounded the alarm from six to ten minutes before the sirens sounded.

The unit sold for $5, and could be installed by a local service shop.

Seventy-five years ago this month, the cover of Popular Mechanics, June 1942, pictured this aircraft spotter with the latest in portable listening equipment. This plane detector featured a parabolic microphone worn as a headpiece. The spotter would listen for the low-pitched hum of an approaching aircraft, and turn his body until the sound was the loudest. He would then be facing the source and could use his binoculars to swiftly and accurately focus in on the plane.

The amplifier, featuring miniature tubes, was worn in a carrying case slung over the shoulder, which also included batteries and accessories. The magazine noted that the set could be used in places where more elaborate units were not available.

For another aircraft detector, see our earlier post.

U.S. dive bombers attacking Japanese carrier. Wikipedia photo.

Today marks the 75th anniversary of two battles of World War II in the Pacific. the Battle of Midway began on June 4, 1942, and the Aleutian Islands Campaign began the day before.

At Midway, the Japanese had intended to eliminate the United States as a strategic power in the Pacific. The Japanese had made faulty assumptions of American reaction, and American cryptographers had been able to determine the date and location of the planned attack. The battle was a U.S. victory, and all four of Japan’s large aircraft carriers were sunk. Along with the Guadalcanal Campaign which began in August, the battle is considered a turning point in the war in the Pacific.

Navy radio station at Dutch Harbor, AK. Wikipedia photo.

On June 3 and 4, the Japanese attacked the SuS. airfield at Dutch Harbor, Alaska.

The attack on Dutch Harbor prompted a blackout of radio stations along the West Coast of North America. According to the June 8, 1942, issue of Broadcasting, stations along the West Coast were silenced for more than eight hours, from 9:01 PM until 5:24 AM the next morning. This was the longest radio blackout to date. Stations in British Columbia, Canada, and Baja California, Mexico, were also off the air for about the same time period.

The magazine noted that the blackout resulted in heavy loss of revenue, but the West Coast stations “cheerfully dug in for the duration.” In most cases, full staff remained on duty. Station switchboards were flooded with calls from listeners, but “operators and attendants on duty kept the public reassured.” According to the magazine, “stations up and down the entire Pacific Coast area have been highly complimented by official Washington, the Army and Navy, as well as by an appreciative public for their efficient cooperation in following through on all orders given.”