After purchasing an RCA AM radio at a swap meet this weekend, I noticed two Civil Defense markings between 600-700 KHz and 1200-1400 KHz. In fact, the Motorola clock radio (mentioned in other Tech Forum postings)has these markings. Were these frequencies to be used by the government in case of a nuclear attack? I'm just curious. Thanks.

Mark

Yes, 640 & 1240 were two frequencies which were to be used in case of an attack. All the regular radio stations would go off the air. Then the stations would take turns transmitting on these frequencies. I remember a few tests. Singal level would go up and down as different stations transmitted. This made it hard to use direction finding equipment.

Norm

: After purchasing an RCA AM radio at a swap meet this weekend, I noticed two Civil Defense markings between 600-700 KHz and 1200-1400 KHz. In fact, the Motorola clock radio (mentioned in other Tech Forum postings)has these markings. Were these frequencies to be used by the government in case of a nuclear attack? I'm just curious. Thanks.

The Conelrad system was the predescesor to the EBS, and it's current replacement.

Ostensibly it was intended for "general national emergencies", but the obvious nuclear attack would qualify.

The tests that Norm recalls, also put a tremendous stress on the transmitters when the test were conducted, which was why the EBS replaced the conelrads.

: Mark

: Yes, 640 & 1240 were two frequencies which were to be used in case of an attack. All the regular radio stations would go off the air. Then the stations would take turns transmitting on these frequencies. I remember a few tests. Singal level would go up and down as different stations transmitted. This made it hard to use direction finding equipment.

: Norm

: : After purchasing an RCA AM radio at a swap meet this weekend, I noticed two Civil Defense markings between 600-700 KHz and 1200-1400 KHz. In fact, the Motorola clock radio (mentioned in other Tech Forum postings)has these markings. Were these frequencies to be used by the government in case of a nuclear attack? I'm just curious. Thanks.

Hi Norm,

When you say that "it made it harder to use direction finding equipment", are you referring to an invading enemy locating a station with direction finding equipment and blowing it up? Is that why the stations took turns transmitting on 640 and 1240? Or were there other reasons?

: Mark

: Yes, 640 & 1240 were two frequencies which were to be used in case of an attack. All the regular radio stations would go off the air. Then the stations would take turns transmitting on these frequencies. I remember a few tests. Singal level would go up and down as different stations transmitted. This made it hard to use direction finding equipment.

: Norm

: : After purchasing an RCA AM radio at a swap meet this weekend, I noticed two Civil Defense markings between 600-700 KHz and 1200-1400 KHz. In fact, the Motorola clock radio (mentioned in other Tech Forum postings)has these markings. Were these frequencies to be used by the government in case of a nuclear attack? I'm just curious. Thanks.

i am doing home work and i need to know what civil defense was like in the 1950's, and what it means, can you guys help me?

:i am doing home work and i need to know what civil defense was like in the 1950's, and what it means, can you guys help me?
:
:
Well, I started grade school in 1959. We did the air raid drills where we climbed under the desk or filed outside into a bus. Many public buildings were outfitted with a shelter, often not much more than a basement with a bunch of canned foods, saltines, water and a radio.
Many of the city thoroughfares were marked as "emergency evacuation" routes so as to give some clue as to how to head out of Dodge in case of an attack.
It got a bit more intense in the early 60s when the nuclear warheads were actually pointed at the US. "Fallout" shelters became the norm and quite a few folks had these built in their back yard. I remember seeing them on display at a home and garden show I went to :-) I don't know if these was ever officially promoted or just marketeering.
Lamentably, none of these efforts would have been any more effective than the latest duct tape episode and its a good thing we never had to depend on these procedures for survival. But a major part of the whole concept then, just as now, was awareness and in that regard it seemed effective.

::i am doing home work and i need to know what civil defense was like in the 1950's, and what it means, can you guys help me?
::
::
:Well, I started grade school in 1959. We did the air raid drills where we climbed under the desk or filed outside into a bus. Many public buildings were outfitted with a shelter, often not much more than a basement with a bunch of canned foods, saltines, water and a radio.
:Many of the city thoroughfares were marked as "emergency evacuation" routes so as to give some clue as to how to head out of Dodge in case of an attack.
:It got a bit more intense in the early 60s when the nuclear warheads were actually pointed at the US. "Fallout" shelters became the norm and quite a few folks had these built in their back yard. I remember seeing them on display at a home and garden show I went to :-) I don't know if these was ever officially promoted or just marketeering.
:Lamentably, none of these efforts would have been any more effective than the latest duct tape episode and its a good thing we never had to depend on these procedures for survival. But a major part of the whole concept then, just as now, was awareness and in that regard it seemed effective.

Bill has given a very good description of civil defense of that era. I started school in 1960, so Bill and I are about the same age. Like him, I remember the drills where the teacher would have us crawl under our desks, etc. As young children, we did not know what all of this really meant, we just knew that was what we were supposed to do when instructed by the teacher. I can remember describing these drills to my parents at home, and they just shaking their heads in bewilderment.
A number of "fallout shelters" were built as free-standing concrete or masonry structures in back yards, as Bill has described. Since I live in West Virginia where terrain is hilly, many of these were partially recessed into hillsides. Some even had ventilation systems where a pipe exited from the roof with an inverted "P-trap", similar to the plumbing drain traps you see underneath sinks, etc. How this would have prevented any nuclear contamination is of course open to debate!
But these elaborate structures were the exception, rather than the rule. Since most homes in my part of the country have basements, it was more common to see a masonry room with a steel door built into the center or corner of a basement. Some people stocked these with 5-gallon glass jugs full of water, canned foods, battery radios and flashlights. I am told that "do-it-yourself" plans for these shelters were available for purchase through magazine and newspaper ads. There were also contractors who styled themselves as "experts" in this field who would custom build these shelters, no doubt at considerable profit to themselves.
As Bill has mentioned, these Civil Defense efforts intensified after Sputnik, when the Soviet Union got the jump on us in their space program and the fear of "attack from space" added to the public concern.
The triangular "Civil Defense" logo which appeared on radio dials indicated the frequency where emergency broadcasts would appear in event of an attack. This same logo, usually in bright yellow and black colors, would be posted on small metal signs outside public buildings which were equipped with fallout shelters. Even today, on older buildings you can still sometimes see these old signs, now usually faded with age.

Poston

As I recall, the system was known as CONELRAD. I'm not 100% sure
of that spelling and sure as heck don't remember what the
acronym stood for. Do you remember, Norm? In the back of my
mind it seems there was an episode of "Fury" -- oh, God, did I
ever date myself -- that picked up on that, although I think
the idea there was that those frequencies could be used for
emergency broadcasts besides those needed in case of a
threatened nuclear strike. But that may have been just TV hype.

Dean

I just happened to be in the dictionary on Saturday looking up
"confab" and happened to see "CONELRAD" right above it! It
stands for CONtrol of ELectromagnetic RADiation.

Dean

During what years were civil defense markings printed on radio dials? I have a clock radio from 1962 which carries these markings. When did they cease using this system?

:During what years were civil defense markings printed on radio dials? I have a clock radio from 1962 which carries these markings. When did they cease using this system?
:

Here are a few links to the "CONELRAD SYSTEMS" I have found,
http://www.westgeorgia.org/conelrad/

http://www.piedmontcommunities.us/servlet/go_ProcServ/dbpage=page&GID=00134000000973802080999925&PG=00139000000976071566049464

http://www.fas.org/nuke/guide/usa/c3i/conelrad.htm

http://www.conelrad.com/media/atomicmusic/ebs_lp68.html

http://www.conelrad.com/perki.html

http://www.northernelectric.ca/radios/cdmarks/cdmarks.htm

Hope this helps, Dennis.