Do you remember CONELRAD? I still remember making/modifying a broadcast receiver that would sound an alarm should an alert be called. You were to switch to either 640 or 1240 KC (now kHz) for instructions. Hams were to cease broadcasting immediately. I will make a point of getting on the air at that time.
Just the word CONELRAD gives me the creeps. I was 5 years old and in kindergarten when the Duck and Cover stuff was going on. It terrified me. I remember one morning at 3 AM a car in my neighborhood caught fire and the horn got stuck and woke me up. I thought it was the sirens and got so scared I got under my bed in the Duck and Cover position. I can still hear those scary sirens.
I remember back in the early 50s they had a test and all stations were off the air for the test as a SWL back then I remember tuning up and down the AM frequency's and only hearing some Mexican stations and weak Canadian stations before the regular broadcast came back on.
Oh, yes. There were a couple of ready-made CONELRAD receivers available to broadcasters, which would fit in a standard 19 inch rack. They were built to decode the 15 seconds of 1 KHz tone coming in from the regional master station, close a relay that would unmute the audio to the built-in speaker, and actuate whatever else you wanted, like a flashing light or a buzzer.
The cheapie receiver that most small stations used was a “Miratel;” basically a standard 5-tube chassis mounted on a rack panel with the tone detector and relay circuit added on. It went for about a hundred bux back in 1960. Of course almost the same radio in consumer table radio form would have been about 10 dollars at the time.
You monitored a station upstream in the hierarchy (usually a large regional or clear channel) who had direct connection to “HQ.”
When the alarm went off (and if it was NOT A TEST) you’d tune to, as you said, either 640 or 1240, where a regional CONELRAD station would go on the air (where it might already be on the air full time as a regular broadcaster). It would have the teletype connection to get the actual emergency message read out on the air, and to stay on the air during the emergency.
If you were a downstream station, your only obligation at that point was to notify your listeners to tune to the CONELRAD frequency, and then get off the air yourself.
You did, however, conduct weekly tests at various times when you could spare a cheap minute of air time. Every station had either a 1 KC (the Hertz wasn’t invented yet!) oscillator, or a 1 KC tone on tape or disc. Best of all was when you had the whole test announcement on tape. Then you could go for a (quick) break, because the whole test was canned.
I well remember it. I used to work as transmitter engineer for a radio station in the early '50s. We had a special receiver for the CONELRAD alert. If it came on, I was to wait for the message to retune your radio to 640 or 1240, then take the transmitter off the air.
Of course the REAL alert never came, but we had practice alerts, with the message for the public being broadcast. Even so, it created a bit of panic when the alert sounded. Is it for real this time?