AM Civil Defense pre-1963

[Deleted User 16173]

This might be a question or questions for Ben Zonia, but can anyone explain how the Civil Defense system operated on AM back before 1963. I know that 640 and 1240 were the channels. Now, if there was a local station on either of those channels did the programming get interrupted for the emergency information? And if there was no local station on those two channels, did the government broadcast emergency information on them? I know that after 1963 radios that were manufactured they stopped putting 640 and 1240 markers on radio dials.

[Round Six]

I found and read a Wiki page about it. I never knew anything about this:

https://en.m.wikipedia.org/wiki/CONELRAD

[kc8yqq]

I remember my first car, a 1963 Buick Lesabre, had both frequencies highlighted on the radio's window.

[HD74]

Supposedly the NORAD channels would be too difficult to radio direction find, as all Primaries would move to these frequencies.
Two older A.M.s I worked at were Primaries and you would set the transmitter to the NORAD frequency you were assigned to.
There was a standard emergency studio setup, with a Collins board and other goodies, lead lined walls were also involved.
Seems like every picture I've seen of one, they all had basically the same gear.

[Ben Zonia]

WJR-FM 96.3 essentially simulcast WJR 760, and apparently had some similar role in warnings. WFBE 95.1 had a big 10 element Yagi at the top of their tower at FCHS to pick this up. The late Ed Rauch told me about that was why it was there, but I cant remember how it was supposed to work.

[HD74]

WKRP had an episode with the infamous orange envelope in it. A tornado hit Cincinnati, and Les opened the envelope, Andy ordered him to just substitute Tornado for Communist, leading to hysterical emergency warnings.

[Deleted User 16171]

I have 3 AM only radios that have the civil defense markers. Two are still working. The one that is non-functional used a mercury battery which I don't think they even make those anymore.

[k8jd]

I recall being shown the mechanisms in the AM transmitter and antenna tower tuning sheds, to change WXYZ's freq from 1270 to 1240 for Conelrad.We updated the monitor reciever from tube to solid state and I got gifted the old tube reciever.

[TC Talks]

Les opened the envelope, Andy ordered him to just substitute Tornado for Communist, leading to hysterical emergency warnings.

I remember the Orange envelope at several stations I worked at. We were told never to open the thing. We would get a new one every so often. I can't remember much more than that from the EAS training I received.

[Ben Zonia]

I recall being shown the mechanisms in the AM transmitter and antenna tower tuning sheds, to change WXYZ's freq from 1270 to 1240 for Conelrad.We updated the monitor reciever from tube to solid state and I got gifted the old tube reciever.

There's some CONELRAD information in the 1960 NAB Engineering Handbook. Whether they switched to 640 or 1240 was not always straightforward, as I remember reading.

https://www.worldradiohistory.com/Archi ... tion-2.pdf

[paul8539]

My understanding is that 640 was for a 'national' channel, as it is a clear channel; 1240 was for the 'local' channel. There were two 640 transmitters, one on the east coast, and one on the west coast, Every city or area had their own 1240 station. Is this understanding correct?