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Pete & Renee Davis September 8th 04 08:26 PM

Civil Defense symbols
 
Can anyone tell me when the civil defense frequencies started being
marked on radio AM dials, and when the markings were discontinued? I
have come across several radio that have them. One was a Motorola add-on
car tube radio (in a stylish shade of turquoise) but no date on the
paperwork, another was a Zenith AM/FM whose paper labels had worn off,
and the other is Bendix Navigator 420 that was listed in catalogs for
1965 (Thanks Walt!).

My Cold War history is a bit sketchy. Could this have come about after
the Cuban Missile Crisis in 1962? I just remember the grown ups being
really worried then, but I probably wasn't even aware of radio at the
time. I'm wondering if anyone on the list can shed some light on these
markings, and whether they might be useful in dating my mystery Zenith.

Pete Davis



Irv Finkleman September 8th 04 08:32 PM

Pete & Renee Davis wrote:

Can anyone tell me when the civil defense frequencies started being
marked on radio AM dials, and when the markings were discontinued? I
have come across several radio that have them. One was a Motorola add-on
car tube radio (in a stylish shade of turquoise) but no date on the
paperwork, another was a Zenith AM/FM whose paper labels had worn off,
and the other is Bendix Navigator 420 that was listed in catalogs for
1965 (Thanks Walt!).

My Cold War history is a bit sketchy. Could this have come about after
the Cuban Missile Crisis in 1962? I just remember the grown ups being
really worried then, but I probably wasn't even aware of radio at the
time. I'm wondering if anyone on the list can shed some light on these
markings, and whether they might be useful in dating my mystery Zenith.

Pete Davis


You can learn lots on Google by looking at the Conelrad (Control of Electromagnetic
Radiation) sites. The concept was developed in 1951 and it was in 1953 that
AM radios had to have the markings on them at 640 and 1240 khz.

Therefore I would suggest your radio was no earlier than 1953, but just
how late the markings continued I don't know -- I didn't bother reading
that far.

Irv VE6BP

Irv
--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

Scott Dorsey September 8th 04 08:34 PM

In article ,
Pete & Renee Davis wrote:
Can anyone tell me when the civil defense frequencies started being
marked on radio AM dials, and when the markings were discontinued? I
have come across several radio that have them. One was a Motorola add-on
car tube radio (in a stylish shade of turquoise) but no date on the
paperwork, another was a Zenith AM/FM whose paper labels had worn off,
and the other is Bendix Navigator 420 that was listed in catalogs for
1965 (Thanks Walt!).


They were not really civil defense frequencies, they were part of the CONELRAD
system. Do a web search on CONELRAD.

As far as I know, the CONELRAD system stuck around until the beginning of EBS.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[email protected] September 9th 04 02:06 AM

On 8 Sep 2004 15:34:27 -0400, (Scott Dorsey) wrote:

In article ,
Pete & Renee Davis wrote:
Can anyone tell me when the civil defense frequencies started being
marked on radio AM dials, and when the markings were discontinued? I
have come across several radio that have them. One was a Motorola add-on
car tube radio (in a stylish shade of turquoise) but no date on the
paperwork, another was a Zenith AM/FM whose paper labels had worn off,
and the other is Bendix Navigator 420 that was listed in catalogs for
1965 (Thanks Walt!).


They were not really civil defense frequencies, they were part of the CONELRAD
system. Do a web search on CONELRAD.


I think it might be reasonable to call them civil defense
frequencies. The "Control" part of the name, as I recall, consisted of
a.) all normal broadcasts were to cease and b.) the broadcasts on the
designated frequencies were arranged to switch among various
transmitters at short intervals. In effect, "spread location",
analogous in a vague way to "spread spectrum".The idea was to have
radio silence, except for the designated stations which each
transmitted in rotating bursts so that enemy aircraft or missiles
could not use a continuously transmitting station as a navigational
beacon.

At least that was the way it was described at the time.



As far as I know, the CONELRAD system stuck around until the beginning of EBS.
--scott



Just curious -- what's the ststus of EBS? I don't recall
hearing any of their tests in quite some time. IIRC, about three to
five years back, there was a dustup over an alert that was sent out as
if live -- no "This is a drill" wrapper was sent with it. When it got
to the radio stations, apparently almost all the GMs (or whoever had
the authority) said, "Naah, this is bogus -- we're not putting this on
the air."


Pete & Renee Davis September 9th 04 12:54 PM

Thanks to all who replied to this thread. This group is one of the few that
are worth a damn when it comes to staying on topic and mutual assistance.

Pete

Pete & Renee Davis wrote:

Can anyone tell me when the civil defense frequencies started being
marked on radio AM dials, and when the markings were discontinued? I
have come across several radio that have them. One was a Motorola add-on
car tube radio (in a stylish shade of turquoise) but no date on the
paperwork, another was a Zenith AM/FM whose paper labels had worn off,
and the other is Bendix Navigator 420 that was listed in catalogs for
1965 (Thanks Walt!).

My Cold War history is a bit sketchy. Could this have come about after
the Cuban Missile Crisis in 1962? I just remember the grown ups being
really worried then, but I probably wasn't even aware of radio at the
time. I'm wondering if anyone on the list can shed some light on these
markings, and whether they might be useful in dating my mystery Zenith.

Pete Davis



Scott Dorsey September 9th 04 03:58 PM

In article ,
wrote:
Just curious -- what's the ststus of EBS? I don't recall
hearing any of their tests in quite some time. IIRC, about three to
five years back, there was a dustup over an alert that was sent out as
if live -- no "This is a drill" wrapper was sent with it. When it got
to the radio stations, apparently almost all the GMs (or whoever had
the authority) said, "Naah, this is bogus -- we're not putting this on
the air."


EBS is gone and has been replaced with the EAS system, which is supposedly
more suited to local disaster events and less for national alerts. It uses
FSK digital data keys rather than the single tone pair for keying. Frankly
it hasn't shown itself to be any real improvement if you ask me.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Chuck Reti September 11th 04 06:37 AM

In article ,
Pete & Renee Davis wrote:

Can anyone tell me when the civil defense frequencies started being
marked on radio AM dials, and when the markings were discontinued? I
have come across several radio that have them. One was a Motorola add-on
car tube radio (in a stylish shade of turquoise) but no date on the
paperwork, another was a Zenith AM/FM whose paper labels had worn off,
and the other is Bendix Navigator 420 that was listed in catalogs for
1965 (Thanks Walt!).

My Cold War history is a bit sketchy. Could this have come about after
the Cuban Missile Crisis in 1962? I just remember the grown ups being
really worried then, but I probably wasn't even aware of radio at the
time. I'm wondering if anyone on the list can shed some light on these
markings, and whether they might be useful in dating my mystery Zenith.

Pete Davis


Check out http://www.conelrad.com/

Chuck Reti
Detroit MI


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