Over a hundred years of journals are available for your reading pleasure on the World Radio History web site. Take a look and enjoy! Read more
Shortwave broadcasting paradox: better, cheaper radios and few broadcast signals. Let’s enjoy the ones that remain. Read more
Today’s AM broadcasters reduce carrier level to save money on their power bills. Here is a summary of the modulation dependent carrier level methods. Read more
Although you don’t know it, most AM broadcasters rapidly adjust their power up and down to save energy costs. The technique is called Modulation Dependent Carrier Level. Read more
Today is World Radio Day 2018. This year’s event celebrates sports broadcasting on the radio, something that continues to be very popular over 100 years. Read more
While the wonders of wireless entertainment swept over the world during the 1930’s, early Soviet radio broadcasting took a much different path. Read more
Hurricane Maria radio communications relied heavily on legacy equipment and ham radio after the “modern infrastructure” just disappeared. Read more
Remember those little triangles on your radio dial? The triangles were the civil defense mark. Between 1951-1963, all AM radios sold in North America needed to be CONELRAD system compliant and part of the emergency broadcasting system. Here’s why and how. Read more
Civil defense sirens were probably the earliest form of emergency broadcasting. Are you old enough to remember the siren near your house?
When I was a kid, civil defense sirens were placed in most of our neighborhoods. I remember one just down the street. It was tested once a month. A very scary sound, especially for kids and their moms.
These civil defense sirens were part of the legacy of air raid sirens from World War II. Only during the 1950’s and 1960’s, they were meant to warn us about atomic war. Strange as it may seem today, many believed atomic war was survivable. Everyone, especially children, was taught about duck and cover. When they were first installed, there was lots of controversy about which level of government should pay to install and maintain them. Here is an interesting newspaper story about their Canadian history in Toronto.
Civil defense sirens are still used all over the world, including North America. Although here, the warning sound is more often about an approaching tornado, or a signal to alert volunteer firefighters.
Today, citizens and governments are trying to protect kids from being scared. Back then, scaring us was the best way to get out attention, apparently.
Civil Defense Sirens and Calgary’s Big Evacuation Test
By the middle of the 1950’s, “duck and cover” gave way to “evacuate”. Wise people figured out that the best way to survive nuclear attack was to go away. In 1955, the City of Calgary conducted one of the only major civil defense evacuations ever held. Operation Lifesaver was a carefully planned warning and evacuation of northeast Calgary. It was thoroughly reported in this Operation Lifesaver documentary.
Good thing this was only a test. The first problem was the weather. Emergency officials originally planned to sound the sirens at 10:50 a.m. on September 21st. The idea was to evacuate northeast Calgary to rural locations, feed them lunch, and then send the home by early evening. Unfortunately a freak snowstorm blocked most of the highways around Calgary. As a result of impassable roads, the test was delayed until September 28th.
The second problem was low participation. Only around 6,000 of the 40,000 population actually evacuated. Most went shopping, instead. After all, it was a day off from school and work. Sigh.
Finally, there was confusion about the sirens. Most people thought the original siren was the “all clear”. For some reason, Canadian and U.S. emergency officials chose the opposite signals that people had gotten use to hearing in newsreels about the Blitz in London, England. Lots of confusion.
Honestly, I am not making this stuff up. It really happened.